<SUBMISSION>
<ACCESSION-NUMBER>0000950123-09-027948
<TYPE>424B5
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20090731
<DATE-OF-FILING-DATE-CHANGE>20090731
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>RXI PHARMACEUTICALS CORP
<CIK>0001390478
<ASSIGNED-SIC>2834
<IRS-NUMBER>000000000
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>424B5
<ACT>33
<FILE-NUMBER>333-158968
<FILM-NUMBER>09975257
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>60 PRESCOTT  STREET
<CITY>WORCESTER
<STATE>MA
<ZIP>01605
<PHONE>508-767-3861
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>60 PRESCOTT  STREET
<CITY>WORCESTER
<STATE>MA
<ZIP>01605
</MAIL-ADDRESS>
</FILER>
<DOCUMENT>
<TYPE>424B5
<SEQUENCE>1
<FILENAME>b76520b5e424b5.htm
<DESCRIPTION>RXI PHARMACEUTICALS CORPORATION
<TEXT>
<HTML>
<HEAD>
<TITLE>e424b5</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
</DIV><!-- END PAGE WIDTH -->
<DIV style="width: 93%; margin-left: 3%"><!-- BEGIN PAGE WIDTH -->

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<TR>
    <TD width="50%"></TD>
    <TD width="50%"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">    <FONT style="font-size: 9pt; font-family: 'Times New Roman', Times">PROSPECTUS
    SUPPLEMENT
    </FONT></TD>
    <TD nowrap align="right">    <FONT style="font-size: 9pt; font-family: 'Times New Roman', Times">
    Filed pursuant to Rule&#160;424(b)(5)
    </FONT></TD>
</TR>

</TABLE>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

<TR>
    <TD width="50%"></TD>
    <TD width="50%"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">    <FONT style="font-size: 9pt; font-family: 'Times New Roman', Times">(To
    Prospectus dated May&#160;22, 2009)
    </FONT></TD>
    <TD nowrap align="right">    <FONT style="font-size: 9pt; font-family: 'Times New Roman', Times">
    Registration
    <FONT style="white-space: nowrap">No.&#160;333-158968</FONT>
    </FONT></TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 12pt">2,385,715&#160;Shares of Common
    Stock</FONT></B>
</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 12pt">Warrants to Purchase
    954,286&#160;Shares of Common Stock</FONT></B>
</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <FONT style="font-size: 26pt">RXI PHARMACEUTICALS CORPORATION
    </FONT>
</DIV>

<DIV style="margin-top: 36pt; font-size: 1pt">&nbsp;</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are offering up to 2,385,715&#160;shares of our common stock
    and warrants to purchase up to 954,286&#160;shares of our common
    stock in this offering (and the shares of common stock issuable
    from time to time upon exercise of these warrants). The common
    stock and warrants will be sold in units, with each unit
    consisting of one share of common stock and a warrant to
    purchase 0.40&#160;shares of common stock at an exercise price
    of $4.50 per share of common stock. Each unit will be sold at a
    negotiated price of $3.50 per unit. The shares of common stock
    and warrants will be issued separately but can only be purchased
    together in this offering.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Units will not be issued or certificated. Our common stock is
    traded on the Nasdaq Capital Market under the symbol
    &#147;RXII.&#148; On July&#160;28, 2009, the closing price of
    our common stock was $4.79 per share.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B>Investing in our securities involves a high degree of risk.
    Before buying any securities, you should read the discussion of
    material risks of investing in our common stock under the
    heading &#147;Risk factors&#148; beginning on
    <FONT style="white-space: nowrap">page&#160;S-4</FONT>
    of this prospectus supplement.</B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B>Neither the Securities and Exchange Commission nor any state
    securities commission has approved or disapproved of these
    securities or passed upon the adequacy or accuracy of this
    prospectus supplement or the accompanying prospectus. Any
    representation to the contrary is a criminal offense.</B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have retained Rodman&#160;&#038; Renshaw, LLC to act as our
    exclusive placement agent in connection with the arrangement of
    this transaction. We have agreed to pay the placement agent the
    placement agent fees set forth in the table below, which assumes
    that we sell all of the units we are offering. We have also
    agreed to issue the placement agent or its designees warrants to
    purchase common stock and to reimburse the placement agent for
    certain of its expenses as described under &#147;Plan of
    distribution&#148; in this prospectus supplement. The placement
    agent is not required to arrange for the sale of any specific
    number of units or dollar amount but will use best efforts to
    arrange for the sale of all of the units.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="73%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="2%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=02 type=lead -->
    <TD width="4%" align="right">&nbsp;</TD>	<!-- colindex=02 type=body -->
    <TD width="1%" align="left">&nbsp;</TD>	<!-- colindex=02 type=hang1 -->
    <TD width="3%">&nbsp;</TD>	<!-- colindex=03 type=gutter -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=03 type=lead -->
    <TD width="14%" align="right">&nbsp;</TD>	<!-- colindex=03 type=body -->
    <TD width="1%" align="left">&nbsp;</TD>	<!-- colindex=03 type=hang1 -->
</TR>
<!-- Table Width Row END -->
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
    <B>Maximum<BR>
    </B>
</TD>
<TD>
&nbsp;
</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
    <B>Offering<BR>
    </B>
</TD>
<TD>
&nbsp;
</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
    <B>Per Unit<BR>
    </B>
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
    <B>Amount</B>
</TD>
<TD>
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Offering price
</DIV>
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
    $
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
    3.50
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
    8,350,002.50
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
</TR>
<TR style="font-size: 1pt">
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Placement agent fees
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    0.21
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    &#160;&#160;&#160;&#160;&#160;&#160;$
</TD>
<TD nowrap align="right" valign="bottom">
    501,000.15
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR style="font-size: 1pt">
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Proceeds, before expenses, to us
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    3.29
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    7,849,002.30
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR style="font-size: 1pt">
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom" style="border-top: 1px solid #000000">
&nbsp;
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We estimate the total expenses of this offering, excluding the
    placement agent fees, will be approximately $82,500. Because
    there is no minimum offering amount required as a condition to
    closing in this offering, the actual offering amount, the
    placement agent fees and net proceeds to us, if any, in this
    offering may be substantially less than the maximum offering
    amounts set forth above.
</DIV>

<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Rodman&#160;&#038;
    Renshaw, LLC<BR>
    </FONT></B>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-size: 10pt; font-family: 'Times New Roman', Times">The
    date of this prospectus supplement is July&#160;30, 2009.
    </FONT>
</DIV>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="width: 93%; margin-left: 3%"><!-- BEGIN PAGE WIDTH -->
</DIV><!-- END PAGE WIDTH -->
<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<DIV align="left">
<!-- TOC -->
</DIV>

<DIV align="left">
<A name="tocpage"></A>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B>This prospectus supplement is not complete without, and may
    not be utilized except in connection with, the accompanying
    prospectus dated May&#160;22, 2009 and any amendments to such
    prospectus. This prospectus supplement provides supplemental
    information regarding us, updates certain information contained
    in the accompanying prospectus and describes the specific terms
    of this offering. The accompanying prospectus gives more general
    information, some of which may not apply to this offering. We
    incorporate important information into this prospectus
    supplement and the accompanying prospectus by reference. You may
    obtain the information incorporated by reference into this
    prospectus supplement and the accompanying prospectus without
    charge by following the instructions under &#147;Where you can
    find more information.&#148; You should carefully read both this
    prospectus supplement and the accompanying prospectus, as well
    as the additional information described under
    &#147;Incorporation of certain documents by reference,&#148;
    before deciding to invest in the units.</B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B>You should rely only on the information contained and
    incorporated by reference in this prospectus supplement and the
    accompanying prospectus. We have not, and the placement agent
    has not, authorized anyone to give you different or additional
    information. You should not assume that the information included
    or incorporated by reference in this prospectus supplement and
    accompanying prospectus is accurate as of any date after the
    respective dates of the documents containing the information.</B>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">TABLE OF
    CONTENTS</FONT></B>
</DIV>

<DIV style="font-size: 3pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->



<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="88%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="4%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="3%">&nbsp;</TD>	<!-- colindex=02 type=quadleft -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=02 type=maindata -->
    <TD width="3%">&nbsp;</TD>	<!-- colindex=02 type=quadright -->
</TR>
<!-- Table Width Row END -->
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="left" valign="bottom">
    <B><FONT style="font-size: 10pt">Prospectus supplement</FONT></B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom">
&nbsp;
</TD>
</TR>
<TR style="line-height: 12pt; font-size: 1pt">
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#101'>Prospectus supplement summary</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-1
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#102'>Risk factors</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-4
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#103'>Note regarding forward-looking statements</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-18
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#104'>Use of proceeds</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-18
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#105'>Price range of common stock</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-19
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#106'>Dividend policy</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-19
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#107'>Dilution</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-20
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#108'>Description of securities</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-21
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#109'>Plan of distribution</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-22
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#110'>Where you can find more information</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-24
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#111'>Incorporation of certain documents by
    reference</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-24
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#112'>Legal matters</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-25
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#113'>Experts</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    S-25
</TD>
<TD>&nbsp;
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="92%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="4%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=02 type=quadleft -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=02 type=maindata -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=02 type=quadright -->
</TR>
<!-- Table Width Row END -->
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="left" valign="bottom">
    <B><FONT style="font-size: 10pt">Prospectus</FONT></B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom">
&nbsp;
</TD>
</TR>
<TR style="line-height: 12pt; font-size: 1pt">
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Summary
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#101'>Our company</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    1
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#102'>Risk factors</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    2
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#103'>Note regarding forward-looking statements</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    2
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#104'>Use of proceeds</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    3
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#105'>Selling Stockholder</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    3
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#106'>Plan of distribution</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    5
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#107'>Description of Common Stock</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    7
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#108'>Description of Preferred Stock</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    8
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#109'>Description of Warrants</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    9
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#110'>Description of Debt Securities</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    10
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#111'>Where you can find more information</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    17
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#112'>Incorporation of documents by reference</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    17
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#113'>Legal matters</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    18
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#114'>Experts</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    18
</TD>
<TD>&nbsp;
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV align="left">
<!-- /TOC -->
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Unless the context otherwise requires, &#147;RXi,&#148; the
    &#147;Company,&#148; &#147;we,&#148; &#147;us,&#148;
    &#147;our&#148; and similar names refer to RXi Pharmaceuticals
    Corporation.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<DIV style="width: 100%; height: 9in; border-top: 1px solid #000000; padding-top: 14pt; border-right: 1px solid #000000; padding-right: 14pt; border-bottom: 1px solid #000000; padding-bottom: 14pt; border-left: 1px solid #000000; padding-left: 14pt"><!-- Begin box 1 -->
<A name='601'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Prospectus
    supplement summary
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>This summary highlights selected information appearing
    elsewhere or incorporated by reference in this prospectus
    supplement and accompanying prospectus and may not contain all
    of the information that is important to you. This prospectus
    supplement and the accompanying prospectus include or
    incorporate by reference information about the shares we are
    offering as well as information regarding our business and
    detailed financial data. You should read this prospectus
    supplement and the accompanying prospectus in their entirety,
    including the information incorporated by reference.</I>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">BUSINESS
    OVERVIEW</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are a discovery-stage biopharmaceutical company pursuing
    proprietary therapeutics based on RNA interference, or RNAi, a
    naturally occurring cellular mechanism for the regulation of
    gene expression that has the potential to be harnessed to
    selectively inhibit the activity of any human gene. As described
    in Kim and Rossi&#146;s review published in March 2007 in Nature
    Reviews Genetics, it is believed that this inhibition may
    potentially treat human diseases by &#147;turning off&#148;
    genes that lead to disease. While no therapeutic RNAi products
    have yet been approved, there has been significant growth in the
    field of RNAi development and potential therapeutic
    applications. This growth is driven by the potential ability to
    use RNAi to rapidly develop lead compounds that specifically and
    selectively inhibit a target gene.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We intend to focus our internal research and development
    programs on certain inflammatory and metabolic diseases, and to
    pursue other therapeutic areas with potential partners. By
    utilizing our expertise in RNAi and the RNAi technology platform
    we have built, we believe we will be able to discover lead
    compounds and move them into clinical development more
    efficiently than traditional drug discovery approaches.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our proprietary technology platform is comprised of two main
    components:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Novel RNAi compounds, referred to as
    rxRNA<SUP style="font-size: 85%; vertical-align: top"><FONT style="font-variant: SMALL-CAPS">tm</FONT></SUP>

    compounds, that are distinct from, and we believe convey
    significant advantages over classic siRNA
    (conventionally-designed &#147;small interfering RNA&#148;
    compounds), and offer many of the properties that we believe are
    important to the clinical development of RNAi-based drugs. We
    have developed unique forms of rxRNA compounds, which have been
    shown to be highly potent.
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Multiple technologies to potentially enable the delivery of our
    rxRNA compounds via local, systemic and oral administration. For
    example, we believe our delivery technologies may enable the
    delivery of rxRNA compounds to macrophages, which are key
    inflammatory cells involved in the progression of various
    inflammatory diseases, resulting in efficient delivery of our
    rxRNA compounds to sites of inflammation. We believe this
    technology provides us with a potential competitive advantage in
    the delivery of RNAi therapeutics, and is a major focus of our
    R&#038;D activities. We are also pursuing other potential
    approaches for the local and systemic delivery of rxRNA
    compounds to other targets of interest, such as certain targets
    involved in metabolic disease.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We intend to use our RNAi technology platform and our expertise
    in RNAi to identify lead compounds and advance towards
    pre-clinical and clinical development programs in the following
    therapeutic areas:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    <I>Inflammatory disease.</I>&#160;Inflammation is responsible
    for a variety of diseases representing significant unmet medical
    need and large market opportunities. Our initial targets include
    validated gene targets related to the TNFa pathway, which is
    involved in many diseases, including, for example, rheumatoid
    arthritis, Crohn&#146;s disease and psoriasis, and our follow-on
    programs involve other novel gene targets that are implicated in
    atherosclerosis, type 2 diabetes and other inflammatory diseases.
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    <I>Metabolic disease.</I>&#160;We have two primary efforts in
    metabolic disease. First, we are targeting an undisclosed gene
    thought to be responsible for elevated cholesterol. We have also
    in-licensed intellectual property developed by Dr.&#160;Michael
    Czech (one of our scientific co-founders and scientific advisory
    board members) on genes that appear to be important regulators
    of metabolism. Studies conducted in Dr.&#160;Czech&#146;s
    laboratory at the University of Massachusetts Medical School
    (UMMS) and by others at Imperial College of London have
    demonstrated that inactivation of one of these genes, called
    RIP140, can cause fat cells to metabolize rather than store fat.
    Mice in these studies that did not express RIP140 remained lean
    and non-diabetic even when maintained on a high-fat diet. We are
    currently designing RNAi compounds targeting RIP140 as a
    potential treatment for obesity and obesity-related type 2
    diabetes.
</TD>
</TR>

</TABLE>
<P>

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-1</FONT></B>
</DIV>
<P></P>
</DIV><!-- End box 1 -->

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<DIV style="width: 100%; height: 9in; border-top: 1px solid #000000; padding-top: 14pt; border-right: 1px solid #000000; padding-right: 14pt; border-bottom: 1px solid #000000; padding-bottom: 14pt; border-left: 1px solid #000000; padding-left: 14pt"><!-- Begin box 1 -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    <I>Additional indications.</I>&#160;There are many well-studied
    genes that have been associated with numerous diseases but have
    been difficult to target with conventional medicinal chemistry.
    We believe RNAi technology may play an important role in
    targeting these genes and potentially treating the related
    diseases. With that in mind, we may also pursue additional
    disease areas with the goal of creating multiple clinical
    development programs, either by our company alone or in
    partnership with pharmaceutical or larger biotechnology
    companies.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We believe that we possess a strong intellectual property
    portfolio. We have secured exclusive, co-exclusive and
    nonexclusive licenses from both academic institutions and
    commercial entities to certain issued and pending patents and
    patent applications covering RNAi technologies in the following
    three categories: (i)&#160;therapeutic targets,
    (ii)&#160;chemistry and configurations of RNAi compounds and
    (iii)&#160;delivery of RNAi compounds within the body. We have
    also filed patents based on our internal discoveries in the each
    of the areas mentioned above.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our principal executive offices are located at 60 Prescott
    Street, Worcester, MA 01605, and our phone number is
    <FONT style="white-space: nowrap">(508)&#160;767-3861.</FONT>
</DIV>
<P>

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-2</FONT></B>
</DIV>
<P></P>
</DIV><!-- End box 1 -->

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<DIV style="width: 100%; height: 9in; border-top: 1px solid #000000; padding-top: 14pt; border-right: 1px solid #000000; padding-right: 14pt; border-bottom: 1px solid #000000; padding-bottom: 14pt; border-left: 1px solid #000000; padding-left: 14pt"><!-- Begin box 1 -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">The offering
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="50%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="2%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="48%">&nbsp;</TD>	<!-- colindex=02 type=maindata -->
</TR>
<!-- Table Width Row END -->
<TR valign="bottom">
<TD align="left" valign="top">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Common stock we are offering
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    2,385,715&#160;shares
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="top">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Common stock to be outstanding after this offering
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    16,207,625&#160;shares
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="top">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Warrants we are offering
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD align="left" valign="bottom">
    Warrants to purchase 954,286&#160;shares of common stock will be
    offered in this offering. The warrants will be exercisable
    during the period commencing six&#160;months after the date of
    original issuance and ending five years from the date the
    warrants become exercisable at an exercise price of $4.50 per
    share of common stock. This prospectus supplement also relates
    to the offering of the shares of common stock issuable upon
    exercise of the warrants.
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="top">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Use of proceeds
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD align="left" valign="bottom">
     We intend to use the net proceeds from the sale of the
    securities covered by this prospectus for general corporate
    purposes, which may include working capital, capital
    expenditures, research and development expenditures, clinical
    trial expenditures, commercial expenditures, acquisitions of new
    technologies or businesses, and investments. See &#147;Use of
    proceeds.&#148;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="top">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Nasdaq Capital Market symbol
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    RXII
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The number of shares of common stock shown above to be
    outstanding after this offering is based on the
    13,821,910&#160;shares outstanding as of July&#160;28, 2009 and
    excludes:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    3,382,342&#160;shares of our common stock subject to options
    outstanding as of July&#160;28, 2009 having a weighted average
    exercise price of $5.53 per share;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    1,295,832&#160;shares of our common stock that have been
    reserved for issuance in connection with future grants under our
    stock option plans as of July&#160;28, 2009;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    332,500&#160;shares of our common stock that have been reserved
    for issuance upon exercise of outstanding warrants as of
    July&#160;28, 2009 having a weighted average exercise price of
    $5.85 per share;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    shares of common stock issuable upon the exercise of warrants
    offered hereby.
</TD>
</TR>

</TABLE>
</DIV><!-- End box 1 -->
<P>

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-3</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<A name='602'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Risk factors
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Investing in our common stock and warrants involves a high
    degree of risk. In addition to the risks related to our business
    set forth in the accompanying prospectus and the other
    information included and incorporated by reference in this
    prospectus supplement and accompanying prospectus, you should
    carefully consider the risks described below before purchasing
    our common stock. If any of the following risks actually occurs,
    our business, results of operations and financial condition will
    likely suffer. As a result, the trading price of our common
    stock may decline, and you might lose part or all of your
    investment.</I>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Risks
    Relating to RXi&#146;s Business and Industry</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">The
    approach we are taking to discover and develop novel
    therapeutics using RNAi is unproven and may never lead to
    marketable products.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The scientific discoveries that form the basis for our efforts
    to discover and develop new drugs are relatively new. The RNAi
    technologies that we have licensed or have created internally
    and that we intend to develop have not yet been clinically
    tested by us, nor are we aware of any clinical trials for
    efficacy having been completed by third parties involving these
    technologies. To date, neither we nor any other company has
    received regulatory approval to market therapeutics utilizing
    RNAi. The scientific evidence to support the feasibility of
    developing drugs based on these discoveries is both preliminary
    and limited. Successful development of RNAi-based products by us
    will require solving a number of issues, including providing
    suitable methods of stabilizing the RNAi material and delivering
    it into target cells in the human body. We may spend large
    amounts of money trying to solve these issues and never succeed
    in doing so. In addition, any compounds that we develop may not
    demonstrate in patients the chemical and pharmacological
    properties ascribed to them in laboratory studies, and they may
    interact with human biological systems in unforeseen,
    ineffective or even harmful ways.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Further, our exclusive focus on RNAi technology for developing
    products as opposed to multiple, more proven technologies for
    drug development increases the risk associated with our
    business. If we are not successful in developing a product
    candidate using RNAi technology, we may not be able to identify
    and successfully implement an alternative product development
    strategy.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We
    will be subject to competition and may not be able to compete
    successfully.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    A number of medical institutions and pharmaceutical companies
    are seeking to develop therapeutic products. Companies working
    in this area include: Alnylam Pharmaceuticals, MDRNA Inc.,
    Cequent Pharmaceuticals, Tacere Therapeutics, Benitec Ltd., OPKO
    Health, Silence Therapeutics, Dicerna Pharmaceuticals, Quark
    Pharmaceuticals, Rosetta Genomics, Lorus Therapeutics and
    Calando Pharmaceuticals, as well as a number of the
    multinational pharmaceutical companies. In addition, a number of
    companies are developing therapeutics for the same diseases we
    are targeting using technologies other than RNA interference.
    Most of these competitors have substantially greater research
    and development capabilities and financial, scientific,
    technical, manufacturing, marketing, distribution, and other
    resources than us, and we may not be able to successfully
    compete with them. In addition, even if we are successful in
    developing our product candidates, in order to compete
    successfully we may need to be first to market or to demonstrate
    that our RNAi based products are superior to therapies based on
    different technologies. If we are not first to market or are
    unable to demonstrate such superiority, any products for which
    we are able to obtain approval may not be successful.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We may
    not be able to maintain the third party relationships that are
    necessary to develop or potentially commercialize some or all of
    our product candidates.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We expect to depend on collaborators, partners, licensees,
    clinical research organizations and other third parties to
    support our discovery efforts, to formulate product candidates,
    and to conduct clinical trials for some or all of our product
    candidates. We cannot guarantee that we will be able to
    successfully negotiate agreements for or maintain relationships
    with collaborators, partners, licensees, clinical investigators
    and other third parties on favorable terms, if at all. If we are
    unable to obtain or maintain these agreements, we may not be
    able to clinically develop, formulate, obtain regulatory
    approvals for or commercialize our product candidates. Under
    certain license agreements that we have already entered into, we
    have minimum dollar amounts per calendar year that we are
    obligated to spend on the development of the technology we have
    licensed from our contract partners. If we fail to
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-4</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    meet this requirement under any of our licenses, we may be in
    breach of our obligations under such agreement which may result
    in the loss of the technology licensed. We cannot necessarily
    control the amount or timing of resources that our contract
    partners will devote to our research and development programs,
    product candidates or potential product candidates, and we
    cannot guarantee that these parties will fulfill their
    obligations to us under these arrangements in a timely fashion.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We
    will rely upon third parties for the manufacture of our clinical
    product candidates.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We do not have the facilities or expertise to manufacture
    supplies of any of our potential product candidates.
    Accordingly, we will be dependent upon contract manufacturers
    for these supplies. We have no manufacturing supply arrangements
    for any of our product candidates, and there can be no assurance
    that we will be able to secure needed supply arrangements on
    attractive terms, or at all. Our failure to secure these
    arrangements as needed could have a materially adverse effect on
    our ability to complete the development of our product
    candidates or, if we obtain regulatory approval for our product
    candidates, to commercialize them.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our current plans call for the manufacture of our rxRNA
    compounds and, as necessary, any delivery vehicles that may be
    used to deliver our rxRNA compounds in vitro such as the
    particles used to delivery our rxRNA compounds to macrophages by
    contract manufacturers offering research grade, Good Laboratory
    grade and Good Manufacturing Practices grade materials for
    preclinical studies (e.g. toxicology studies) and for clinical
    use. The chemistry, manufacturing and controls for RNAi active
    pharmaceutical ingredient will be addressed by our clinical
    development team in close collaboration with a contract
    manufacturer with extensive experience in RNA drug synthesis.
    RNA is a complex molecule requiring many synthesis steps, which
    may lead to challenges with purification and
    <FONT style="white-space: nowrap">scale-up.</FONT>
    These challenges could result in increased costs and delays in
    manufacturing. Additionally, although we are not currently aware
    of any such litigation or threatened litigation or challenge, if
    we have litigation or threatened litigation for or challenge to
    the composition of our products candidates in the future,
    manufacturers may refuse to manufacture such compounds.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Any
    drug candidates we develop may fail in development or be delayed
    or may not be commercially viable.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    All of our products in development must be approved by the FDA
    or similar foreign governmental agencies before they can be
    marketed. The process for obtaining FDA approval is both
    time-consuming and costly, with no certainty of a successful
    outcome. This process typically includes the conduct of
    extensive preclinical and clinical testing, which may take
    longer or cost more than we anticipate, and may prove
    unsuccessful due to numerous factors. Product candidates that
    may appear to be promising at early stages of development may
    not successfully reach the market for a number of reasons. The
    results of pre-clinical and initial clinical testing of these
    products may not necessarily indicate the results that will be
    obtained from later or more extensive testing. Companies in the
    pharmaceutical and biotechnology industries have suffered
    significant setbacks in advanced clinical trials, even after
    obtaining promising results in earlier trials.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We, the FDA or other applicable regulatory authorities, or an
    institutional review board (&#147;IRB&#148;), an independent
    committee under the oversight of the United States Department of
    Health and Human Services (&#147;HHS&#148;), which has been
    formally registered with HHS and functions to approve, monitor
    and review biomedical and behavioral research involving humans,
    may suspend clinical trials of a drug candidate at any time for
    various reasons, including if we or they believe the subjects or
    patients participating in such trials are being exposed to
    unacceptable health risks. Among other reasons, adverse side
    effects of a drug candidate on subjects or patients in a
    clinical trial could result in the FDA or other regulatory
    authorities suspending or terminating the trial and refusing to
    approve a particular drug candidate for any or all indications
    of use.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Clinical trials of a new drug candidate require the enrollment
    of a sufficient number of patients, including patients who are
    suffering from the disease the drug candidate is intended to
    treat and who meet other eligibility criteria. Rates of patient
    enrollment are affected by many factors, and delays in patient
    enrollment can result in increased costs and longer development
    times.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Clinical trials also require the review and oversight of IRBs,
    which approve and continually review clinical investigations and
    protect the rights and welfare of human subjects. An inability
    or delay in obtaining IRB approval could prevent or delay the
    initiation and completion of clinical trials and the FDA may
    decide not to consider any data or information derived from a
    clinical investigation not subject to initial and continuing IRB
    review and approval.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-5</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Numerous factors could affect the timing, cost or outcome of our
    drug development efforts, including the following:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Delays in filing initial drug applications,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Difficulty in securing centers to conduct trials,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Conditions imposed on us by the FDA or comparable foreign
    authorities regarding the scope or design of our clinical trials,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Problems in engaging IRBs to oversee trials or problems in
    obtaining or maintaining IRB approval of studies,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Difficulty in enrolling patients in conformity with required
    protocols or projected timelines,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Unexpected adverse reactions by patients in trials,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Difficulty in obtaining clinical supplies of the product,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Negative or inconclusive results from our clinical trials or the
    clinical trials of others for drug candidates similar to our own
    or inability to generate statistically significant data
    confirming the efficacy of the product being tested,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Changes in the FDA&#146;s requirements for our testing during
    the course of that testing,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Modification of the drug during testing,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Reallocation of our limited financial and other resources to
    other clinical programs,&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Adverse results obtained by other companies developing RNAi
    drugs.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The substances we are intending to develop may represent a new
    class of drug, and the FDA has not yet established any
    definitive policies, practices or guidelines in relation to
    these drugs. While we expect any product candidates that we
    develop will be regulated as a new drug under the Federal Food,
    Drug, and Cosmetic Act, the FDA could decide to regulate them or
    other products we may develop as biologics under the Public
    Health Service Act. The lack of policies, practices or
    guidelines may hinder or slow review by the FDA of any
    regulatory filings that we may submit. Moreover, the FDA may
    respond to these submissions by defining requirements that we
    may not have anticipated.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    It is possible that none of the product candidates that we
    develop will obtain the appropriate regulatory approvals
    necessary for us to begin selling them or that any regulatory
    approval to market a product may be subject to limitations on
    the indicated uses for which we may market the product. The time
    required to obtain FDA and other approvals is unpredictable but
    often can take years following the commencement of clinical
    trials, depending upon the complexity of the drug candidate. Any
    analysis we perform of data from clinical activities is subject
    to confirmation and interpretation by regulatory authorities,
    which could delay, limit or prevent regulatory approval. Any
    delay or failure in obtaining required approvals could have a
    material adverse effect on our ability to generate revenue from
    the particular drug candidate.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are also subject to numerous foreign regulatory requirements
    governing the conduct of clinical trials, manufacturing and
    marketing authorization, pricing and third-party reimbursement.
    The foreign regulatory approval process includes all of the
    risks associated with FDA approval described above as well as
    risks attributable to the satisfaction of local regulations in
    foreign jurisdictions. Approval by the FDA does not assure
    approval by regulatory authorities outside of the United States.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">The
    FDA approval process may be delayed for any drugs we develop
    that require the use of specialized drug delivery devices or
    vehicles.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Some drug candidates that we develop may need to be administered
    using specialized vehicles that deliver RNAi therapeutics
    directly to diseased parts of the body. For example, we
    anticipate using an implantable pump to deliver drug candidates
    to the nervous system. While we expect to rely on drug delivery
    vehicles that have been approved by the FDA or other regulatory
    agencies to deliver our drug candidates, we may need to modify
    the design or labeling of these delivery vehicles for some
    products we may develop. In such an event, the FDA may regulate
    the product as a combination product of a drug and a device or
    require additional approvals or clearances for the
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-6</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    modified delivery. Additionally, it has been observed in at
    least one previous clinical trial, conducted by another company,
    that delivery vehicles similar to the delivery vehicle
    in-licensed from UMMS may cause toxicity, which could delay or
    prevent approval of this delivery vehicle.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Further, to the extent the specialized delivery vehicle is owned
    by another company, we would need that company&#146;s
    cooperation to implement the necessary changes to the vehicle,
    or its labeling, and to obtain any additional approvals or
    clearances. Any delays in finding suitable drug delivery
    vehicles to administer RNAi therapeutics directly to diseased
    parts of the body could negatively affect our ability to
    successfully develop our RNAi therapeutics.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">If we
    are not successful in developing pre-clinical product
    candidates, we will not be able to commence clinical trials in
    humans or obtain approval for our product
    candidates.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are in the new drug discovery phase and we have not yet
    identified any lead compounds for therapeutic development in our
    initial areas of focus. RNA interference is a relatively new
    scientific field, and the technologies are still in the early
    stage of development. We have no compounds in pre-clinical
    toxicology studies, and we may not be able to advance any
    product candidate through the pre-clinical stage into clinical
    trials. Additionally, our development efforts may never result
    in the identification of a pre-clinical candidate which we are
    able to successfully develop into a drug. Even if we are able to
    designate a lead candidate, we may not be able to identify data
    that would support entering such a candidate into clinical
    trials. Furthermore, even if we successfully enter into clinical
    studies, the results from pre-clinical testing of a drug
    candidate may not predict the results that will be obtained on
    human clinical trials.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">If our
    pre-clinical testing does not produce successful results or our
    clinical trials do not demonstrate safety and efficacy in
    humans, we will not be able to commercialize our drug
    candidates.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Before obtaining regulatory approval for the sale of our drug
    candidates, we must conduct, at our own expense, extensive
    pre-clinical tests and clinical trials to demonstrate the safety
    and efficacy in humans of our drug candidates. However, we are
    required to do extensive testing in animal models with our
    product candidates before we can be approved by the FDA to
    initiate clinical trials in humans. Furthermore, we cannot be
    sure that our product candidates will be safely tolerated by
    humans or be efficacious. Pre-clinical and clinical testing is
    expensive, difficult to design and implement, can take many
    years to complete and is uncertain as to outcome. Success in
    pre-clinical testing and early clinical trials does not ensure
    that later clinical trials will be successful, and interim
    results of a clinical trial do not necessarily predict final
    results.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    A failure of one or more of our pre-clinical studies or clinical
    trials can occur at any stage of testing. We may experience
    numerous unforeseen events during, or as a result of, the
    pre-clinical testing and the clinical trial process that could
    delay or prevent our ability to receive regulatory approval or
    potentially commercialize our drug candidates, including:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Regulators or IRBs may not authorize us to commence a clinical
    trial or conduct a clinical trial at a prospective trial site,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Our pre-clinical tests or clinical trials may produce negative
    or inconclusive results, and we may decide, or regulator may
    require us, to conduct additional pre-clinical testing or
    clinical trials, or we may abandon projects that we previously
    expected to be promising,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Enrollment in our clinical trials may be slower than we
    anticipate or participants may drop out of our clinical trials
    at a higher rate than we anticipate, resulting in significant
    delays,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Our third party contractors may fail to comply with regulatory
    requirements or meet their contractual obligations to us in a
    timely manner,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    Our drug candidates may have very different chemical and
    pharmacological properties in humans than in laboratory testing
    and it may interact with human biological systems in unforeseen,
    ineffective or harmful ways,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    We might have to suspend or terminate our clinical trials if the
    participants are being exposed to unacceptable health risks,
</TD>
</TR>

</TABLE>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-7</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    IRBs or regulators, including the FDA, may require that we hold,
    suspend or terminate clinical research for various reasons,
    including noncompliance with regulatory requirements,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    the cost of our clinical trials may be greater than we
    anticipate,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    the supply or quality of our drug candidates or other necessary
    materials necessary to conduct our clinical trials may be
    insufficient or inadequate,&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    effects of our drug candidates may not be the desired effects or
    may include undesirable side effects or the drug candidates may
    have other unexpected characteristics.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Even
    if we obtain regulatory approvals, our marketed drugs will be
    subject to ongoing regulatory review. If we fail to comply with
    continuing U.S. and foreign regulations, we could lose our
    approvals to market drugs and our business would be materially
    adversely affected.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Following any initial regulatory approval of any drugs we may
    develop, we will also be subject to continuing regulatory
    review, including the review of adverse drug experiences and
    clinical results that are reported after our drug products are
    made available to patients. This would include results from any
    post marketing tests or vigilance required as a condition of
    approval. The manufacturer and manufacturing facilities we use
    to make any of our drug candidates will also be subject to
    periodic review and inspection by the FDA. The discovery of any
    new or previously unknown problems with the product,
    manufacturer or facility may result in restrictions on the drug
    or manufacturer or facility, including withdrawal of the drug
    from the market. Our product promotion and advertising also will
    be subject to regulatory requirements and continuing regulatory
    review. If we fail to comply with applicable continuing
    regulatory requirements, we may be subject to fines, suspension
    or withdrawal of regulatory approval, product recalls and
    seizures, operating restrictions and other adverse consequences.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Even
    if we receive regulatory approval to market our product
    candidates, our product candidates may not be accepted
    commercially, which may prevent us from becoming
    profitable.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The product candidates that we are developing are based on new
    technologies and therapeutic approaches. RNAi products are
    expected to be substantially more expensive to manufacture than
    traditional small molecule drugs, which may make them more
    costly than competing small molecule drugs. Additionally, RNAi
    products are likely to require injection or implantation, and do
    not readily cross the so-called blood brain barrier, which will
    make them less convenient to administer than drugs administered
    orally. Key participants in the pharmaceutical marketplace, such
    as physicians, medical professionals working in large reference
    laboratories, public health laboratories and hospitals,
    third-party payors and consumers, may not accept products
    intended to improve therapeutic results based on RNAi
    technology. As a result, it may be more difficult for us to
    convince the medical community and third-party payors to accept
    and use our product, or to provide favorable reimbursement. And
    if medical professionals working with large reference
    laboratories, public health laboratories and hospitals choose
    not to adopt and use our RNAi technology, our products may not
    achieve broader market acceptance.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Other factors that we believe will materially affect market
    acceptance of our product candidates include:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The timing of our receipt of any marketing approvals, the terms
    of any approvals and the countries in which approvals are
    obtained,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The safety, efficacy and ease of administration of our product
    candidates,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The advantages of our product candidates over those of our
    competitors,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The willingness of patients to accept relatively new therapies,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The success of our physician education programs,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The availability of government and third-party payor
    reimbursement,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The pricing of our products, particularly as compared to
    alternative treatments,&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    The availability of effective alternative treatments and the
    relative risks
    <FONT style="white-space: nowrap">and/or</FONT>
    benefits of the treatments.
</TD>
</TR>

</TABLE>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-8</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We may
    be unable to protect our intellectual property rights licensed
    from UMMS or others, our intellectual property rights may be
    inadequate to prevent third parties from using our technologies
    or developing competing products, and we may need to license
    additional intellectual property from others.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have a non-exclusive license to the Mello and Fire
    foundational RNAi patent owned by UMMS and the Carnegie
    Institution of Washington, which claims various aspects of RNAi
    or genetic inhibition by double stranded RNA. This license
    continues to be available to third parties, and as such it does
    not provide us with the ability to exclude others from its use
    or protect us from competition. Therapeutic applications of gene
    silencing technologies, delivery methods, and other technologies
    that we license from UMMS are also claimed in a number of UMMS
    pending patent applications, but there can be no assurance that
    these applications will result in any issued patents or that
    those patents would withstand possible legal challenges or
    protect our technologies from competition. United States Patent
    and Trademark Office and patent granting authorities in other
    countries have upheld stringent standards for the RNAi patents
    that have been prosecuted so far. Consequently, pending patents
    that we have licensed may continue to experience long and
    difficult prosecution challenges and may ultimately issue with
    much narrower claims than those in the pending applications. We
    are aware of a number of issued patents covering various
    particular forms and compositions of RNAi-mediating molecules
    and therapeutic methods that we do not currently expect to use.
    Third parties may, however, hold or seek to obtain additional
    patents that could make it more difficult or impossible for us
    to develop products based on the gene silencing technology that
    we have licensed.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In addition, others may challenge the patent owned by UMMS and
    the Carnegie Institution of Washington or other patents that we
    currently license or may license in the future and, as a result,
    these patents could be narrowed, invalidated or rendered
    unenforceable, which would negatively affect our ability to
    exclude others from use of RNAi technologies described in these
    patents. There can be no assurance that these patent or other
    pending applications or issued patents we licensed in will
    withstand possible legal challenges. Moreover, the laws of some
    foreign countries may not protect our proprietary rights to the
    same extent as do the laws of the United States. Any patents
    issued to us or our licensors may not provide us with any
    competitive advantages, and there can be no assurance that the
    patents of others will not have an adverse effect on our ability
    to do business or to continue to use our technologies freely.
    Our efforts to enforce and maintain our intellectual property
    rights may not be successful and may result in substantial costs
    and diversion of management time. Even if our rights are valid,
    enforceable and broad in scope, competitors may develop products
    based on technology that is not covered by our licenses.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may need to license additional intellectual property rights
    from third parties in order to be able to complete the
    development or enhance the efficacy of our product candidates or
    avoid possible infringement of the rights of others.
    Additionally, many of our UMMS licenses are limited to ALS,
    obesity, diabetes and cancer, and in order to pursue other
    diseases against proprietary gene targets, we may need licenses
    from other third parties that may be unavailable. To the extent
    that we are required to obtain multiple licenses from third
    parties to develop or commercialize a product candidate, the
    aggregate licensing fees and milestones and royalty payments
    made to these parties may materially reduce our economic returns
    or even cause us to abandon development or commercialization of
    a product candidate. Accordingly, there is no assurance that we
    will be able to acquire any additional intellectual property
    rights on satisfactory terms, or at all.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In addition to our licenses, we also rely on copyright and
    trademark protection, trade secrets, know-how, continuing
    technological innovation and licensing opportunities. In an
    effort to maintain the confidentiality and ownership of our
    trade secrets and proprietary information, we require our
    employees, consultants, advisors and others to whom we disclose
    confidential information to execute confidentiality and
    proprietary information agreements. However, it is possible that
    these agreements may be breached, invalidated or rendered
    unenforceable, and if so, there may not be an adequate
    corrective remedy available. Furthermore, like many companies in
    our industry, we may from time to time hire scientific personnel
    formerly employed by other companies involved in one or more
    areas similar to the activities we conduct. In some situations,
    our confidentiality and proprietary information agreements may
    conflict with, or be subject to, the rights of third parties
    with whom our employees, consultants or advisors have prior
    employment or consulting relationships. Although we require our
    employees and consultants to maintain the confidentiality of all
    confidential information of previous employers, we or these
    individuals may be subject to allegations of trade secret
    misappropriation or other similar claims as a result of their
    prior affiliations. Finally, others may independently develop
    substantially equivalent proprietary information and techniques,
    or otherwise gain access to our trade secrets. Our failure to
    protect our proprietary information and techniques may inhibit
    or limit our ability to exclude certain competitors from the
    market and execute our business strategies.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-9</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Our
    success depends upon our ability to obtain and maintain
    intellectual property protection for our products and
    technologies.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our success will depend on our ability to obtain and maintain
    adequate protection of our intellectual property covering our
    product candidates and technologies. The ultimate degree of
    patent protection that will be afforded to biotechnology
    products and processes, including ours, in the United States and
    in other important markets remains uncertain and is dependent
    upon the scope of protection decided upon by the patent offices,
    courts and lawmakers in these countries. There is no certainty
    that our existing patents, or patent applications if obtained,
    will afford us substantial protection or commercial benefit.
    Similarly, there is no assurance that our pending patent
    applications or patent applications licensed from third parties
    will ultimately be granted as patents or that those patents that
    have been issued or are issued in the future will stand if they
    are challenged in court.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    There may be patent or other intellectual property rights
    belonging to others that require us to alter our products, pay
    licensing fees or cease certain activities. If our products
    infringe patent or other intellectual property rights of others,
    the owners of those rights could bring legal actions against us
    claiming damages and seeking to enjoin manufacturing and
    marketing of the affected products. If these legal actions are
    successful, in addition to any potential liability for damages,
    we could be required to obtain a license in order to continue to
    manufacture or market the affected products. We may not prevail
    in any action brought against us, and any license required under
    any rights that we infringe may not be available on acceptable
    terms or at all.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Other
    companies or organizations may assert patent rights that prevent
    us from developing our products.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    RNA interference is a relatively new scientific field that has
    generated many different patent applications from organizations
    and individuals seeking to obtain important patents in the
    field. These applications claim many different methods,
    compositions and processes relating to the discovery,
    development, delivery and commercialization of RNAi
    therapeutics. Because the field is so new, very few of these
    patent applications have been fully processed by government
    patent offices around the world, and there is a great deal of
    uncertainty about which patents will issue, when, to whom, and
    with what claims. While we are not aware of any litigation,
    threatened litigation or challenge to our intellectual property
    rights, it is likely that there will be significant litigation
    and other proceedings, such as interference and opposition
    proceedings in various patent offices, relating to patent rights
    in the RNAi field. Others may attempt to invalidate our
    intellectual property rights or those of our licensors. Even if
    our rights, or those of our licensors, are not directly
    challenged, disputes among third parties could lead to the
    weakening or invalidation of our intellectual property rights.
    Any attempt by third parties to circumvent or invalidate our
    intellectual property rights could be costly to defend, require
    significant time and attention of our management and have a
    material adverse effect on our business.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We are
    dependent on technologies we license, and if we lose the right
    to license such technologies or we fail to license new
    technologies in the future, our ability to develop new products
    would be harmed.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We currently are dependent on licenses from third parties for
    our key technologies relating to fundamental RNAi technologies.
    Our current licenses impose, and any future licenses we enter
    are likely to impose, various development, funding, royalty,
    diligence, sublicensing, insurance and other obligations on us.
    If our license with respect to any of these technologies is
    terminated for any reason, the development of the products
    contemplated by the licenses would be delayed, or suspended
    altogether, while we seek to license similar technology or
    develop new non-infringing technology. The costs of obtaining
    new licenses are high, and many patents in the RNAi field have
    already been exclusively licensed to third parties, including
    our competitors. If any of our existing licenses is terminated,
    the development of the products contemplated by the licenses
    could be delayed or terminated and we may not be able to
    negotiate additional licenses on acceptable terms, if at all,
    which would have a material adverse effect on our business.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We are
    subject to potential liabilities from clinical testing and
    future product liability claims.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If any of our future products are alleged to be defective, they
    may expose us to claims for personal injury by patients in
    clinical trials of our products or by patients using our
    commercially marketed products. Even if the marketing of one or
    more of our products is approved by the FDA, users may claim
    that such products caused unintended adverse effects. We will
    seek to obtain clinical trial insurance for clinical trials that
    we conduct, as well as liability insurance for any products that
    we market. There can be no assurance that we will be able to
    obtain
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-10</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

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<P></P>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    insurance in the amounts we seek, or at all. We anticipate that
    licensees who develop our products will carry liability
    insurance covering the clinical testing and marketing of those
    products. There is no assurance, however, that any insurance
    maintained by us or our licensees will prove adequate in the
    event of a claim against us. Even if claims asserted against us
    are unsuccessful, they may divert management&#146;s attention
    from our operations and we may have to incur substantial costs
    to defend such claims.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Any
    drugs we develop may become subject to unfavorable pricing
    regulations, third-party reimbursement practices or healthcare
    reform initiatives, which could have a material adverse effect
    on our business.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We intend to sell our products primarily to hospitals which
    receive reimbursement for the health care services they provide
    to their patients from third-party payors, such as Medicare,
    Medicaid and other domestic and international government
    programs, private insurance plans and managed care programs.
    Most third-party payors may deny reimbursement if they determine
    that a medical product was not used in accordance with
    cost-effective treatment methods, as determined by the
    third-party payor, or was used for an unapproved indication.
    Third-party payors also may refuse to reimburse for experimental
    procedures and devices. Furthermore, because our programs are in
    the early stages of development, we are unable at this time to
    determine their cost-effectiveness and the level or method of
    reimbursement. Increasingly, the third-party payors who
    reimburse patients are requiring that drug companies provide
    them with predetermined discounts from list prices, and are
    challenging the prices charged for medical products. If the
    price we are able to charge for any products we develop is
    inadequate in light of our development and other costs, our
    profitability could be adversely effected.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We currently expect that any drugs we develop may need to be
    administered under the supervision of a physician. Under
    currently applicable law, drugs that are not usually
    self-administered may be eligible for coverage by the Medicare
    program if:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    They are &#147;incidental&#148; to a physician&#146;s services,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    They are &#147;reasonable and necessary&#148; for the diagnosis
    or treatment of the illness or injury for which they are
    administered according to accepted standard of medical practice,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    They are not excluded as immunizations,&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    They have been approved by the FDA.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    There may be significant delays in obtaining insurance coverage
    for newly-approved drugs, and insurance coverage may be more
    limited than the purpose for which the drug is approved by the
    FDA. Moreover, eligibility for insurance coverage does not imply
    that any drug will be reimbursed in all cases or at a rate that
    covers our costs, including research, development, manufacture,
    sale and distribution. Interim payments for new drugs, if
    applicable, may also not be sufficient to cover our costs and
    may not be made permanent. Reimbursement may be based on
    payments for other services and may reflect budgetary
    constraints or imperfections in Medicare data. Net prices for
    drugs may be reduced by mandatory discounts or rebates required
    by government health care programs or private payors and by any
    future relaxation of laws that presently restrict imports of
    drugs from countries where they may be sold at lower prices than
    in the United States. Third-party payors often rely upon
    Medicare coverage policy and payment limitations in setting
    their own reimbursement rates. Our inability to promptly obtain
    coverage and profitable reimbursement rates from both
    government-funded and private payors for new drugs that we
    develop could have a material adverse effect on our operating
    results, our ability to raise capital needed to develop
    products, and our overall financial condition.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Additionally, third-party payors are increasingly attempting to
    contain health care costs by limiting both coverage and the
    level of reimbursement for medical products and services. A
    number of legislative and regulatory proposals to change the
    healthcare system in the United States and other major
    healthcare markets have been proposed in recent years and
    currently are under consideration in Congress. These proposals
    have included prescription drug benefit legislation recently
    enacted in the United States and healthcare reform legislation
    enacted by certain states. Levels of reimbursement may decrease
    in the future, and future legislation, regulation or
    reimbursement policies of third-party payors may adversely
    affect the demand for and price levels of our products. If our
    customers are not reimbursed for our products, they may reduce
    or discontinue purchases of our products, which could have a
    material adverse effect on our business, financial condition and
    results of operations.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-11</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

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<P></P>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Some states and localities have established drug importation
    programs for their citizens, and federal drug import legislation
    has been introduced in Congress. The Medicare Prescription Drug
    Plan legislation, which became law in December 2003, required
    the Secretary of Health and Human Services to promulgate
    regulations for drug reimportation from Canada into the United
    States under some circumstances, including when the drugs are
    sold at a lower price than in the United States. The Secretary,
    however, retained the discretion not to implement a drug
    reimportation plan if he finds that the benefits do not outweigh
    the costs, and has so far declined to approve a reimportation
    plan. Proponents of drug reimportation may attempt to pass
    legislation that would directly allow reimportation under
    certain circumstances. Legislation or regulations allowing the
    reimportation of drugs, if enacted, could decrease the price we
    receive for any products that we may develop and adversely
    affect our future revenues and prospects for profitability.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">If we
    fail to attract, hire and retain qualified personnel, we may not
    be able to design, develop, market or sell our products or
    successfully manage our business.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are highly dependent on our named executive officers and
    Scientific Advisory Board (&#147;SAB&#148;) members. The
    continued service of our named executive officers and SAB
    members is critical to our success. We have entered into
    employment agreements with our named executive officers, all of
    which can be terminated by such persons on short or no notice.
    The loss of any of our named executive officers or SAB members,
    or our inability to identify, attract, retain and integrate
    additional qualified key personnel, could make it difficult for
    us to manage our business successfully and achieve our business
    objectives.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Competition for skilled research, product development,
    regulatory and technical personnel also is intense, and we may
    not be able to recruit and retain the personnel we need. The
    loss of the services of any key research, product development,
    regulatory, and technical personnel, or our inability to hire
    new personnel with the requisite skills, could restrict our
    ability to develop our product candidates.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We use
    biological and hazardous materials and if we do not comply with
    laws regulating the protection of the environment and health and
    human safety, our business could be adversely
    affected.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our research and development activities involve the controlled
    use of potentially harmful biological materials as well as
    hazardous materials, chemicals and various radioactive
    compounds. We cannot completely eliminate the risk of accidental
    contamination or injury; we could be held liable for any damages
    that result, and any liability could exceed our resources. We
    are subject to federal, state and local laws and regulations
    governing the use, storage, handling and disposal of these
    materials and specific waste products. We are also subject to
    numerous environmental, health and workplace safety laws and
    regulations, including those governing laboratory procedures,
    exposure to blood-borne pathogens and the handling of
    biohazardous materials. The cost of compliance with these laws
    and regulations could be significant and may adversely affect
    capital expenditures to the extent we are required to procure
    expensive capital equipment to meet regulatory requirements.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are also subject to numerous environmental, health and
    workplace safety laws and regulations, including those governing
    laboratory procedures, exposure to blood-borne pathogens and the
    handling of biohazardous materials. We maintain workers&#146;
    compensation insurance to cover us for costs and expenses we may
    incur due to injuries to our employees resulting from the use of
    these materials. The limits of our workers&#146; compensation
    insurance are mandated by state law, and our workers&#146;
    compensation liability is capped at these state-mandated limits.
    We do not maintain insurance for environmental liability or
    toxic tort claims that may be asserted against us in connection
    with our storage or disposal of biological, hazardous or
    radioactive materials. Additional federal, state and local laws
    and regulations affecting our operations may be adopted in the
    future. We may incur substantial costs to comply with, and
    substantial fines or penalties if we violate any of these laws
    or regulations.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Risks
    Relating to a Publicly Traded Company and Future Financing
    Needs</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">You
    may have difficulty evaluating our business, because we have
    limited history and our historical financial information may not
    be representative of our future results.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The historical financial information included in our Annual
    Report on
    <FONT style="white-space: nowrap">Form&#160;10-K</FONT>
    for the year ended December&#160;31, 2008 does not necessarily
    reflect the financial condition, results of operations or cash
    flows that we would have achieved as a separate company during
    the periods presented or those that we will achieve in the
    future. Prior to the contribution of our RNAi assets from CytRx
    Corporation (&#147;CytRx&#148;), our RNAi research and
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-12</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    development activities were conducted by CytRx as part of its
    broader operations, rather than as an independent division or
    subsidiary, and were primarily conducted through sponsored
    research arrangements rather than through internal activities.
    CytRx also performed various corporate functions relating to our
    business, as discussed above. Our historical financial
    information reflects allocations of indirect expenses from CytRx
    for these and similar functions. We believe that these
    allocations are comparable to the expenses we would have
    incurred had we operated as a separate company, although we may
    incur higher expenses as a separate company.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We
    have limited operating experience and may not be able to
    effectively operate.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are a discovery-stage company with limited operating history.
    We will focus solely on developing and, if we obtain regulatory
    approval for our product candidates, commercializing therapeutic
    products based upon RNAi technologies, and there is no assurance
    that we will be able to successfully implement our business
    plan. While our management collectively possesses substantial
    business experience, there is no assurance that we will be able
    to manage our business effectively, or that we will be able to
    identify, hire and retain any needed additional management or
    scientific personnel to develop and implement our product
    development plans, obtain third-party contracts or any needed
    financing, or achieve the other components of our business plan.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">The
    obligations associated with being an independent public company
    require significant resources and management
    attention.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    As a publicly traded company, we are subject to the reporting
    requirements of the U.S.&#160;Securities Exchange Act of 1934,
    as amended (the &#147;Exchange Act&#148;), and the
    Sarbanes-Oxley Act of 2002. In addition, the Exchange Act
    requires that we file annual, quarterly and current reports. Our
    failure to prepare and disclose this information in a timely
    manner could subject us to penalties under federal securities
    laws, expose us to lawsuits and restrict our ability to access
    financing. The Sarbanes-Oxley Act requires that we, among other
    things, establish and maintain effective internal controls and
    procedures for financial reporting and we are presently
    evaluating our existing internal controls in light of the
    standards adopted by the Public Company Accounting Oversight
    Board. It is possible that we or our independent registered
    public accounting firm may identify significant deficiencies or
    material weaknesses in our internal control over financial
    reporting in the future. Any failure or difficulties in
    implementing and maintaining these controls could cause us to
    fail to meet the periodic reporting obligations or result in
    material misstatements in our financial statements.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Section&#160;404 of the Sarbanes-Oxley Act requires annual
    management assessments of the effectiveness of our internal
    control over financial reporting. Our failure to satisfy the
    requirements of Section&#160;404 on a timely basis could result
    in the loss of investor confidence in the reliability of our
    financial statements, which in turn could have a material
    adverse effect on our business and our common stock.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We may
    not be able to obtain sufficient financing, and may not be able
    to develop our product candidates.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We believe that our existing cash, cash equivalents, and
    potential proceeds from this offering and the Standby Equity
    Distribution Agreement, or SEDA, we entered into on
    January&#160;30, 2009 with YA Global Master SPV Ltd., or YA
    Global, should be sufficient to fund our operations through
    2010. In the future, we will be dependent on obtaining further
    financing from third parties in order to maintain our operations
    and to meet our financial obligations. Before we are able to
    access additional capital from the SEDA, we must satisfy certain
    conditions, including the requirement that shares of our stock
    to be sold to YA Global be registered with the
    U.S.&#160;Securities and Exchange Commission (&#147;SEC&#148;),
    and there is risk of delays in our satisfying these conditions.
    In addition, pursuant to the terms of the securities purchase
    agreement related to this offering, we are prohibited from
    issuing shares under the SEDA for a period of 30&#160;days. We
    cannot assure that additional debt or equity or other funding to
    maintain our operations and to meet our obligations to our
    licensors will be available to us in the future on acceptable
    terms, or at all. If we fail to obtain additional funding when
    needed, we would be forced to scale back, or terminate, our
    operations, or to seek to merge with or to be acquired by
    another company.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We anticipate that we will need to raise substantial amounts of
    money to fund a variety of future activities integral to the
    development of our business, which may include but are not
    limited to the following:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    to conduct research and development to successfully develop our
    RNAi technologies,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    to obtain regulatory approval for our products,
</TD>
</TR>

</TABLE>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-13</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    to file and prosecute patent applications and to defend and
    assess patents to protect our technologies,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    to retain qualified employees, particularly in light of intense
    competition for qualified scientists,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    to manufacture products ourselves or through third parties,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    to market our products, either through building our own sales
    and distribution capabilities or relying on third
    parties,&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    to acquire new technologies, licenses, products or companies.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We cannot assure you that any financing needed for the
    development of our business will be available to us on
    acceptable terms or at all. If we cannot obtain additional
    financing in the future, our operations may be restricted and we
    may ultimately be unable to continue to develop and potentially
    commercialize our product candidates.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Future
    financing may be obtained through, and future development
    efforts may be paid for by, the issuance of debt or equity,
    which may have an adverse effect on our stockholders or may
    otherwise adversely affect our business.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If we raise funds through the issuance of debt or equity, any
    debt securities or preferred stock issued will have rights,
    preferences and privileges senior to those of holders of our
    common stock in the event of a liquidation. In such event, there
    is a possibility that once all senior claims are settled, there
    may be no assets remaining to pay out to the holders of common
    stock. In addition, if we raise funds through the issuance of
    additional equity, whether through private placements or
    additional public offerings, such an issuance would dilute your
    ownership in us.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The terms of debt securities may also impose restrictions on our
    operations, which may include limiting our ability to incur
    additional indebtedness, to pay dividends on or repurchase our
    capital stock, or to make certain acquisitions or investments.
    In addition, we may be subject to covenants requiring us to
    satisfy certain financial tests and ratios, and our ability to
    satisfy such covenants may be affected by events outside of our
    control.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We
    expect to continue to incur significant research and development
    expenses, which may make it difficult for us to attain
    profitability, and may lead to uncertainty about or as to our
    ability to continue as a going concern.</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Substantial funds were expended to develop our RNAi
    technologies, and additional substantial funds will be required
    for further research and development, including pre-clinical
    testing and clinical trials of any product candidates, and to
    manufacture and market any products that are approved for
    commercial sale. Because the successful development of our
    products is uncertain, we are unable to precisely estimate the
    actual funds we will require to develop and potentially
    commercialize them. In addition, we may not be able to generate
    enough revenue, even if we are able to commercialize any of our
    product candidates, to become profitable.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In the event that we are unable to achieve or sustain
    profitability or to secure additional financing, we may not be
    able to meet our obligations as they come due, raising
    substantial doubts as to our ability to continue as a going
    concern. Any such inability to continue as a going concern may
    result in our common stock holders losing their entire
    investment. There is no guaranty that we will become profitable
    or secure additional financing. Our financial statements
    contemplate that we will continue as a going concern and do not
    contain any adjustments that might result if we were unable to
    continue as a going concern. Changes in our operating plans, our
    existing and anticipated working capital needs, the acceleration
    or modification of our expansion plans, increased expenses,
    potential acquisitions or other events will all affect our
    ability to continue as a going concern.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Risks
    Related to Ownership of Our Common Stock</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">The
    market price and trading volume of our common stock may be
    volatile</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The market price of our common stock could fluctuate
    significantly for many reasons, including the following factors:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    announcements of regulatory developments or technological
    innovations by us or our competitors,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    changes in our relationship with our licensors and other
    strategic partners,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    changes in our ownership or other relationships with CytRx,
</TD>
</TR>

</TABLE>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-14</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    our quarterly operating results,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    developments in patent or other technology ownership rights,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    public concern regarding the safety of our products,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    government regulation of drug pricing,&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    general changes in the economy, the financial markets or the
    pharmaceutical or biotechnology industries.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In addition, factors beyond our control may also have an impact
    on the price of our stock. For example, to the extent that other
    large companies within our industry experience declines in their
    stock price, our stock price may decline as well. In addition,
    when the market price of a company&#146;s common stock drops
    significantly, stockholders often institute securities class
    action lawsuits against the company. A lawsuit against us could
    cause us to incur substantial costs and could divert the time
    and attention of our management and other resources.
</DIV>

<DIV style="margin-top: 15pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Future
    sales of our shares by CytRx, or the possibility of such sales,
    could adversely affect our stock price.</FONT></I></B>
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx owns 6,268,881&#160;shares of our common stock, or
    approximately 46% of our outstanding shares. We have agreed
    that, upon request by CytRx, we will use our best efforts to
    cause all of our shares issued to CytRx pursuant to the two
    contribution agreements we entered into in relation to our
    initial capitalization to be registered under the Securities
    Act, with certain exceptions, with all expenses incurred in
    connection with any such registration will be borne by us.
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We also have granted CytRx what are commonly known as
    &#147;piggyback&#148; registration rights to include our shares
    currently owned by CytRx, or owned by CytRx in the future as a
    result of a dividend or distribution with respect to shares
    currently owned by CytRx, in other registration statements that
    we may file with the SEC on behalf of our company or our
    security holders. CytRx exercised this &#147;piggyback&#148;
    registration right in relation to our recent registration
    statement on Form&#160;S-3, to which this prospectus supplement
    relates, in which 500,000&#160;shares owned by CytRx were
    registered for resale on an on-going basis. The availability of
    our shares held by CytRx for resale publicly, as well as any
    actual sales of these shares, could adversely affect the market
    price of our shares.
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If the value of our shares owned by CytRx from time to time were
    to exceed 40% of the value of CytRx&#146;s total assets, CytRx
    may be deemed an &#147;investment company&#148; within the
    meaning of the Investment Company Act of 1940 and become subject
    to the stringent regulations applicable to investment companies.
    In this event, CytRx would likely seek to promptly sell or
    otherwise dispose of shares of our common stock in order to
    avoid becoming an inadvertent investment company. Any such sales
    or other disposition by CytRx of our shares, or the possibility
    of such sales or disposition, could adversely affect the market
    price of our shares.
</DIV>

<DIV style="margin-top: 15pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We
    have granted CytRx preemptive rights to acquire shares that we
    may sell in the future, which may impair our ability to raise
    funds.</FONT></I></B>
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Under an agreement between us, CytRx and our founding
    stockholders, with some exceptions, CytRx has preemptive rights
    to acquire a portion of any new securities sold or issued by us
    so as to maintain its percentage ownership of us at the time of
    any such sale and issuance, which is currently approximately 46%
    of our outstanding shares. The exercise by CytRx of its
    preemptive rights may impair our ability to raise funds, or
    adversely affect the terms on which we are able to raise funds,
    as we may not be able to offer to new investors the quantity of
    our stock that they may desire to purchase.
</DIV>

<DIV style="margin-top: 15pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">CytRx&#146;s
    ownership of our common stock could delay or prevent a change in
    corporate control.</FONT></I></B>
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx owns approximately 46% of our common stock, and has
    preemptive rights, as described above, to maintain its
    percentage ownership. CytRx has agreed with UMMS, us and our
    other founding stockholders to vote its shares of our common
    stock so that a majority of the members of our board of
    directors are not affiliated with CytRx. However, by virtue of
    its stock ownership, CytRx may be able to significantly
    influence the outcome of matters required to be submitted to a
    vote of our stockholders, including any proposed amendments to
    our certificate
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-15</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    of incorporation and approval of mergers and other significant
    corporate transactions. This concentration of ownership may
    adversely affect the market price of our common stock by:
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    delaying, deferring or preventing a change in control of our
    company,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    impeding a merger, consolidation, takeover or other business
    combination involving our company,&#160;or
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    discouraging a potential acquirer from making a tender offer or
    otherwise attempting to obtain control of our company.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 15pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">CytRx
    could unilaterally effect a change of control of our company by
    selling or disposing of our shares owned by it.</FONT></I></B>
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If CytRx were to sell or otherwise dispose of all or a
    significant portion of our shares owned by it to a single buyer
    or group of affiliated buyers, it could effect a change of
    control of our company without the advice or participation by
    our board of directors or other stockholders, since transferees
    of the shares owned by CytRx will not be bound by CytRx&#146;s
    agreements with UMMS, us and our other founding stockholders not
    to vote our shares owned by it for the election of a majority of
    our board of directors who are affiliated with CytRx.
</DIV>

<DIV style="margin-top: 15pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Anti-takeover
    provisions of our certificate of incorporation and by-laws and
    provisions of Delaware law could delay or prevent a change of
    control that you may favor.</FONT></I></B>
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Anti-takeover provisions of our certificate of incorporation and
    by-laws and provisions of Delaware law may discourage, delay or
    prevent a merger or other change of control that stockholders
    may consider favorable, or may impede the ability of the holders
    of our common stock to change our management. These provisions
    of our certificate of incorporation and by-laws, among other
    things:
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    divide our board of directors into three classes, with members
    of each class to be elected for staggered three-year terms,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    limit the right of stockholders to remove directors,
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    regulate how stockholders may present proposals or nominate
    directors for election at annual meetings of
    stockholders,&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;&#160;
</TD>
    <TD align="left">
    authorize our board of directors to issue preferred stock in one
    or more series, without stockholder approval.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In addition, Section&#160;203 of the Delaware General
    Corporation Law provides that, subject to limited exceptions,
    persons that acquire, or are affiliated with a person that
    acquires, more than 15% of the outstanding voting stock of a
    Delaware corporation such as our company shall not engage in any
    business combination with that corporation, including by merger,
    consolidation or acquisitions of additional shares for a
    three-year period following the date on which that person or its
    affiliate crosses the 15% stock ownership threshold.
    Section&#160;203 could operate to delay or prevent a change of
    control of our company.
</DIV>

<DIV style="margin-top: 15pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">We may
    acquire other businesses or form joint ventures that may be
    unsuccessful and could adversely dilute your ownership of our
    company.</FONT></I></B>
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    As part of our business strategy, we may pursue future
    acquisitions of other complementary businesses and technology
    licensing arrangements. We also may pursue strategic alliances.
    We have no experience with respect to acquiring other companies
    and limited experience with respect to the formation of
    collaborations, strategic alliances and joint ventures. If we
    were to make any acquisitions, we may not be able to integrate
    these acquisitions successfully into our existing business and
    we could assume unknown or contingent liabilities. We also could
    experience adverse effects on our reported results of operations
    from acquisition related charges, amortization of acquired
    technology and other intangibles and impairment charges relating
    to write-offs of goodwill and other intangible assets from time
    to time following the acquisition. Integration of an acquired
    company also may require management resources that otherwise
    would be available for ongoing development of our existing
    business. We
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-16</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    may not identify or complete these transactions in a timely
    manner, on a cost-effective basis, or at all, and we may not
    realize the anticipated benefits of any acquisition, technology
    license or strategic alliance.
</DIV>

<DIV style="margin-top: 9pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    To finance acquisitions, we may choose to issue shares of our
    common stock as consideration, which would dilute your ownership
    interest in us. Alternatively, it may be necessary for us to
    raise additional funds through public or private financings.
    Additional funds may not be available on terms that are
    favorable to us and, in the case of equity financings, may
    result in dilution to our stockholders. Any future acquisitions
    by us also could result in large and immediate write-offs, the
    incurrence of contingent liabilities or amortization of expenses
    related to acquired intangible assets, any of which could harm
    our operating results.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-17</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<A name='603'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Note
    regarding forward-looking statements
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    This prospectus supplement, the accompanying prospectus, any
    free writing prospectus used in connection with this offering
    and the other documents we have filed with the SEC that are
    incorporated herein by reference contain forward-looking
    statements within the meaning of the Private Securities
    Litigation Reform Act of 1995 that involve risks and
    uncertainties, as well as assumptions that, if they never
    materialize or prove incorrect, could cause our results to
    differ materially from those expressed or implied by such
    forward-looking statements. All statements other than statements
    of historical fact are statements that could be deemed
    forward-looking statements, including any projections of
    financing needs, revenue, expenses, earnings or losses from
    operations, or other financial items; any statements of the
    plans, strategies and objectives of management for future
    operations; any statements concerning product research,
    development and commercialization plans and timelines; any
    statements regarding safety and efficacy of product candidates;
    any statements of expectation or belief; and any statements of
    assumptions underlying any of the foregoing. All forward-looking
    statements attributable to us or to persons acting on our behalf
    are expressly qualified in their entirety by the cautionary
    statements and risk factors set forth in Risk factors and
    elsewhere in this prospectus supplement, our
    <FONT style="white-space: nowrap">Form&#160;10-K</FONT>
    for the year ended December&#160;31, 2008 and our
    <FONT style="white-space: nowrap">Form&#160;10-Q</FONT>
    for the fiscal quarter ended March&#160;30, 2009. In addition,
    forward-looking statements may contain the words
    &#147;believe,&#148; &#147;anticipate,&#148; &#147;expect,&#148;
    &#147;estimate,&#148; &#147;intend,&#148; &#147;plan,&#148;
    &#147;project,&#148; &#147;will be,&#148; &#147;will
    continue,&#148; &#147;will result,&#148; &#147;seek,&#148;
    &#147;could,&#148; &#147;may,&#148; &#147;might,&#148; or any
    variations of such words or other words with similar meanings.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Given these uncertainties, you should not place undue reliance
    on these forward-looking statements. You should read this
    prospectus supplement, the accompanying prospectus and the
    documents that we reference in this prospectus with the
    understanding that our actual future results may be materially
    different from what we expect. Except as required by law, we do
    not undertake any obligation to update or revise any
    forward-looking statements contained in this prospectus and any
    supplements to this prospectus, whether as a result of new
    information, future events or otherwise.
</DIV>
<A name='604'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Use of
    proceeds
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We estimate that the net proceeds from the sale of the
    2,385,715&#160;units will be approximately $7,766,500, assuming
    that we sell the maximum number of units we are offering
    pursuant to this prospectus supplement. Because there is no
    minimum offering amount required as a condition to the closing
    of this offering, the actual number of units sold, placement
    agent fees and proceeds to us are not presently determinable and
    may be substantially less than the maximum amount set forth
    above.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We intend to use the net proceeds of this offering for general
    corporate purposes, which may include working capital, capital
    expenditures, research and development expenditures, clinical
    trial expenditures, commercial expenditures, acquisitions of new
    technologies or businesses, and investments.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-18</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<A name='605'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Price range
    of common stock
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our common stock trades on the Nasdaq Capital Market under the
    symbol &#147;RXII.&#148; The following table sets forth, for the
    periods indicated, the high and low intraday sales prices per
    share of our common stock as reported by the Nasdaq Capital
    Market. These prices do not include retail markups, markdowns or
    commissions.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="67%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="9%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=02 type=lead -->
    <TD width="5%" align="right">&nbsp;</TD>	<!-- colindex=02 type=body -->
    <TD width="1%" align="left">&nbsp;</TD>	<!-- colindex=02 type=hang1 -->
    <TD width="12%">&nbsp;</TD>	<!-- colindex=03 type=gutter -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=03 type=lead -->
    <TD width="3%" align="right">&nbsp;</TD>	<!-- colindex=03 type=body -->
    <TD width="1%" align="left">&nbsp;</TD>	<!-- colindex=03 type=hang1 -->
</TR>
<!-- Table Width Row END -->
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
    <FONT style="font-size: 10pt">High
    </FONT>
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="2" nowrap align="center" valign="bottom">
    <FONT style="font-size: 10pt">Low
    </FONT>
</TD>
<TD>
&nbsp;
</TD>
</TR>
<TR style="line-height: 3pt; font-size: 1pt">
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Fiscal year ending December&#160;31, 2008
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 40pt">
    First quarter
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    23.95
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    6.01
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 40pt">
    Second quarter
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    10.12
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    5.22
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 40pt">
    Third quarter
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    9.05
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    6.42
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 40pt">
    Fourth quarter
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    12.25
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    5.41
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="line-height: 12pt">
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Fiscal year ending December&#160;31, 2009
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 40pt">
    First quarter
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    7.19
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    3.90
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 40pt">
    Second quarter
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    7.57
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    4.00
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 40pt">
    Third quarter (through July&#160;28, 2009)
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    4.93
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    3.15
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The last reported sales price of our common stock on the Nasdaq
    Capital Market on July&#160;28, 2009 was $4.79 per share. As of
    July&#160;28, 2009, there were outstanding
    13,821,910&#160;shares of our common stock outstanding.
</DIV>
<A name='606'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Dividend
    policy
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have never paid any dividends and do not anticipate paying
    any dividends on our common stock in the foreseeable future. We
    expect to retain future earnings, if any, for use in our
    development activities and the operation of our business.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-19</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<A name='607'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Dilution
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If you invest in our common stock and warrants, you will
    experience dilution to the extent of the difference between the
    price per share you pay in this offering and the net tangible
    book value per share of our common stock immediately after this
    offering.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our net tangible book value as of June 30, 2009 was
    approximately $3.2&#160;million, or $0.23 per share of common
    stock. Net tangible book value per share is equal to our total
    tangible assets minus total liabilities, all divided by the
    number of shares of common stock outstanding as of July&#160;28,
    2009. After giving effect to the sale of 2,385,715&#160;shares
    of common stock, at an offering price of $3.50 per share, and
    after deducting our estimated placement agent fees and offering
    expenses payable by us, our as adjusted net tangible book value
    would have been approximately $10,989,500, or approximately
    $0.68 per share of common stock, as of July&#160;30, 2009. This
    represents an immediate increase in net tangible book value of
    approximately $0.45 per share to existing stockholders and an
    immediate dilution of approximately $2.82 per share to new
    investors. The following table illustrates this calculation on a
    per share basis:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 8pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="80%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="5%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=02 type=lead -->
    <TD width="5%" align="right">&nbsp;</TD>	<!-- colindex=02 type=body -->
    <TD width="1%" align="left">&nbsp;</TD>	<!-- colindex=02 type=hang1 -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=03 type=gutter -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=03 type=lead -->
    <TD width="5%" align="right">&nbsp;</TD>	<!-- colindex=03 type=body -->
    <TD width="1%" align="left">&nbsp;</TD>	<!-- colindex=03 type=hang1 -->
</TR>
<!-- Table Width Row END -->
<TR valign="bottom" style="background: #CCEEFF">
<TD align="left" valign="bottom">
<DIV style="text-indent: -8pt; margin-left: 8pt">
    Offering price for one share of common stock and one warrant to
    purchase 0.40&#160;shares of common stock
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    $3.50
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -8pt; margin-left: 16pt">
    Net tangible book value per share as of June 30, 2009
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    $0.23
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD align="left" valign="bottom">
<DIV style="text-indent: -8pt; margin-left: 16pt">
    Increase per share attributable to the offering
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    $0.45
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="font-size: 1pt">
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -8pt; margin-left: 8pt">
    As adjusted net tangible book value per share after this offering
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    0.68
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="font-size: 1pt">
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD style="border-top: 1px solid #000000">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD align="left" valign="bottom">
<DIV style="text-indent: -8pt; margin-left: 8pt">
    Dilution per share to new investors
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    2.82
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom" style="font-size: 1pt">
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD style="border-top: 3px double #000000">
&nbsp;
</TD>
<TD style="border-top: 3px double #000000">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Because there is no minimum offering amount required as a
    condition to the closing of this offering, the dilution per
    share to new investors may be more than that indicated above in
    the event that the actual number of units sold, if any, is less
    than the maximum number of units we are offering.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The above illustration of dilution per share to investors
    participating in this offering assumes (i)&#160;no exercise of
    outstanding options to purchase our common stock or outstanding
    warrants to purchase shares of our common stock; and
    (ii)&#160;no exercise of the warrants offered hereby. The
    exercise of outstanding options and warrants having an exercise
    price less than the offering price will increase dilution to new
    investors.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Investors that purchase common stock upon the exercise of the
    warrants offered hereby may experience dilution depending on our
    net tangible book value (deficit) at the time of exercise.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The number of shares of common stock shown above to be
    outstanding after this offering is based on the
    13,821,910&#160;shares outstanding as of July&#160;28, 2009 and
    excludes:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    3,382,342&#160;shares of our common stock subject to options
    outstanding as of July&#160;28, 2009 having a weighted average
    exercise price of $5.53 per share;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    1,295,832&#160;shares of our common stock that have been
    reserved for issuance in connection with future grants under our
    stock option plans as of July&#160;28, 2009;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    332,500&#160;shares of our common stock that have been reserved
    for issuance upon exercise of outstanding warrants as of
    July&#160;28, 2009 having a weighted average exercise price of
    $5.85 per share;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    shares of common stock issuable upon the exercise of warrants
    offered hereby.
</TD>
</TR>

</TABLE>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-20</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<A name='608'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Description
    of securities
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In this offering, we are offering a maximum of
    2,385,715&#160;units, each consisting of (i)&#160;one share of
    our common stock and (ii)&#160;a warrant to purchase up to
    0.40&#160;shares of our common stock at an exercise price of
    $4.50 per share.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Units will not be issued or certificated. The shares of common
    stock and warrants are immediately separable and will be issued
    separately. This prospectus supplement also relates to the
    offering of shares of our common stock issuable upon exercise,
    if any, of the warrants.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Common
    Stock</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The material terms and provisions of our common stock are
    described under the caption &#147;Description of Common
    Stock&#148; starting on page&#160;7 of the accompanying
    prospectus.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Warrants</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The warrants offered in this offering will be issued pursuant to
    a securities purchase agreement between each of the purchasers
    and us. The following is a brief summary of the material terms
    of the warrants and is subject in all respects to the provisions
    contained in the warrants. A form of the warrants is being filed
    as an exhibit to our Current Report on
    <FONT style="white-space: nowrap">Form&#160;8-K</FONT>
    that we will file with the SEC in connection with this offering
    and reference is made thereto for a complete description of the
    warrants.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Exercise Price.</I>&#160;The exercise price per share of
    common stock purchasable upon exercise of the warrants is $4.50
    per share of common stock being purchased. If we, at any time
    while the warrants are outstanding, (i)&#160;pay a stock
    dividend or otherwise make a distribution or distributions on
    shares of common stock or any other equity or equity equivalent
    securities payable in shares of common stock,
    (ii)&#160;subdivides outstanding shares of common stock into a
    larger number of shares, (iii)&#160;combines (including by way
    of reverse stock split) outstanding shares of common stock into
    a smaller number of shares, or (iv)&#160;issues by
    reclassification of shares of the common stock any shares of
    capital stock, then in each case the exercise price shall be
    multiplied by a fraction of which the numerator shall be the
    number of shares of common stock (excluding treasury shares, if
    any) outstanding immediately before such event and of which the
    denominator shall be the number of shares of common stock
    outstanding immediately after such event, and the number of
    shares issuable upon exercise of the warrants shall be
    proportionately adjusted such that the aggregate exercise price
    of the warrants shall remain unchanged.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Exercisability.</I>&#160;Holders may exercise the warrants
    beginning on the date that is six months after the date of
    original issuance and at any time up to the date that is five
    years after the closing of the offering.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Cashless Exercise.</I>&#160;If at any time during the warrant
    exercisability period the issuance of shares of our common stock
    upon exercise of the warrant is not covered by an effective
    registration statement, or the prospectus contained therein is
    not available for the issuance of the common stock to the
    holder, the holders are permitted to effect a cashless exercise
    of the warrants (in whole or in part) by surrendering the
    warrants to us, together with delivery to us of a duly executed
    exercise notice, canceling a portion of the warrant in payment
    of the purchase price payable in respect of the number of shares
    of our common stock purchased upon such exercise.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Transferability.</I>&#160;The warrants may be transferred at
    the option of the warrant holder upon surrender of the warrants
    with the appropriate instruments of transfer.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Exchange Listing.</I>&#160;We do not plan on making an
    application to list the warrants on the Nasdaq Capital Market,
    any national securities exchange or other nationally recognized
    trading system.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Rights as a Stockholder.</I>&#160;Except as otherwise
    provided in the warrants or by virtue of such holder&#146;s
    ownership of shares of our common stock, the holders of the
    warrants do not have the rights or privileges of holders of our
    common stock, including any voting rights, until they exercise
    their warrants.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Fundamental Transactions.</I>&#160;In the event of any
    fundamental transaction, as described in the warrants and
    generally including any merger with another entity, the sale,
    transfer or other disposition of all or substantially all of our
    assets to another entity, or the acquisition by a person of more
    than 50% of our common stock, then the holders of the warrants
    will thereafter have the right to receive upon exercise of the
    warrants such shares of stock, securities or assets as would
    have been issuable or payable with respect to or in exchange for
    a number of shares of our common stock equal to the number of
    shares of our common stock issuable upon exercise of the
    warrants immediately prior
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-21</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    to the fundamental transaction, had the fundamental transaction
    not taken place, and appropriate provision will be made so that
    the provisions of the warrants (including, for example,
    provisions relating to the adjustment of the exercise price)
    will thereafter be applicable, as nearly equivalent as may be
    practicable in relation to any share of stock, securities or
    assets deliverable upon the exercise of the warrants after the
    fundamental transaction.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In the event of a fundamental transaction that is (1)&#160;an
    all cash transaction, (2)&#160;a
    <FONT style="white-space: nowrap">&#147;Rule&#160;13e-3</FONT>
    transaction&#148; as defined in
    <FONT style="white-space: nowrap">Rule&#160;13e-3</FONT>
    under the Exchange Act, or (3)&#160;a fundamental transaction
    involving a person or entity not traded on a national securities
    exchange, the holders of the warrants may require us to redeem
    the warrant for a purchase price payable in case of the
    Black-Scholes value of the warrant, as calculated pursuant to
    the terms of the warrant.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <I>Limits on Exercise of Warrants.</I>&#160;Except upon at least
    61&#160;days&#146; prior notice from the holder to us, the
    holder will not have the right to exercise any portion of the
    warrant if the holder, together with its affiliates, would
    beneficially own in excess of 4.99% of the number of shares of
    our common stock (including securities convertible into common
    stock) outstanding immediately after the exercise.
</DIV>
<A name='609'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Plan of
    distribution
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Pursuant to a placement agency agreement between us and
    Rodman&#160;&#038; Renshaw, LLC, we have engaged
    Rodman&#160;&#038; Renshaw, LLC as our exclusive placement agent
    to solicit offers to purchase the units in this offering. The
    placement agent is not purchasing or selling any of the units we
    are offering, and they are not required to arrange the purchase
    or sale of any specific number of units or dollar amount, but
    they have agreed to use best efforts to arrange for the sale of
    the units.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The placement agent proposes to arrange for the sale of the
    units we are offering pursuant to this prospectus supplement to
    one or more investors through securities purchase agreement
    directly between the purchasers and us. All of the units will be
    sold at the same price and, we expect, at a single closing. We
    established the price following negotiations with prospective
    investors and with reference to the prevailing market price of
    our common stock, recent trends in such price and other factors.
    It is possible that not all of the units we are offering
    pursuant to this prospectus supplement will be sold at the
    closing, in which case our net proceeds would be reduced. We
    expect that the sale of the units will be completed on the date
    indicated on the cover page of this prospectus supplement.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In connection with this offering, the placement agent may
    distribute this prospectus supplement and the accompanying
    prospectus electronically.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will pay the placement agent a placement agent fee equal to
    6% of the gross proceeds of this offering. The following table
    shows the per share and total placement agent fees we will pay
    to the placement agent in connection with the sale of the units,
    assuming the purchase of all of the units we are offering.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="86%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="2%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=02 type=lead -->
    <TD width="10%" align="right">&nbsp;</TD>	<!-- colindex=02 type=body -->
    <TD width="1%" align="left">&nbsp;</TD>	<!-- colindex=02 type=hang1 -->
</TR>
<!-- Table Width Row END -->
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    Per unit
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    0.21
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 20pt">
    Total
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="left" valign="bottom">
    $
</TD>
<TD nowrap align="right" valign="bottom">
    501,000.15
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    As additional compensation, we will issue the placement agent,
    or it designee, warrants to purchase shares of common stock
    equal to (i)&#160;1% of the aggregate number of securities
    placed in the offering if the gross proceeds of the offering are
    less than 10,000,000, and 2% of the aggregate number of
    securities placed in the offering if the gross proceeds of the
    offering are 10,000,000 or more. These warrants shall have an
    exercise price equal to $4.50, and shall be exercisable for a
    term of five years from the effective date of the registration
    statement to which this prospectus supplement is a part of, have
    no price-based dilution protection, have no registration rights
    and shall be restricted from transfer for a period of six months
    from the closing date except as expressly permitted by FINRA
    Rule&#160;5110(g).
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We estimate the total expenses of this offering which will be
    payable by us, excluding the placement agent fees, will be
    approximately $82,500. We may also reimburse the placement agent
    for certain fees and legal expenses reasonably incurred by them.
    Under no circumstances will any fees, discounts, commissions or
    concessions received by the placement agent and any FINRA member
    or independent broker-dealer exceed 8% of the gross proceeds of
    the offering. The estimated offering expenses payable by us, in
    addition to the placement agent fees of $501,000, are
    approximately $583,500, which includes legal, accounting and
    printing costs and various other fees associated with
    registering and listing the common stock. After deducting
    certain fees due to the placement agent and our estimated
    offering expenses, we expect the net proceeds from this offering
    to be approximately $7,766,500.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-22</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have agreed to indemnify the placement agent against certain
    liabilities, including liabilities under the Securities Act of
    1933, as amended, and liabilities arising from breaches and
    representations and warranties contained in the placement agency
    agreement. We have also agreed to contribute to payments the
    placement agent may be required to make in respect of such
    liabilities.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The placement agency agreement is included as an exhibit to our
    Current Report on
    <FONT style="white-space: nowrap">Form&#160;8-K</FONT>
    that we will file with the SEC in connection with this offering.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">NASDAQ
    GLOBAL MARKET</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our common stock is quoted on the Nasdaq Capital Market under
    the symbol &#147;RXII.&#148;
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">PRICE
    STABILIZATION</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The placement agent has informed us that it will not engage in
    over-allotment, stabilizing transactions or syndicate covering
    transactions in connection with this offering.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">AFFILIATION</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The placement agent and its affiliates may provide certain
    commercial banking, financial advisory or investment banking
    services for us for which they receive fees. The placement agent
    and its affiliates may from time to time in the future engage in
    transactions with us and perform services for us in the ordinary
    course of its business.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-23</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
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<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<A name='610'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Where you
    can find more information
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We file annual, quarterly and current reports, proxy statements
    and other information with the SEC. Our SEC filings are
    available to the public over the Internet at the SEC&#146;s
    website at
    <I><FONT style="white-space: nowrap">http://www.sec.gov</FONT></I>.
    The SEC&#146;s website contains reports, proxy and information
    statements and other information regarding issuers, such as us,
    that file electronically with the SEC. You may also read and
    copy any document we file with the SEC at the SEC&#146;s Public
    Reference Room at 100&#160;F&#160;Street, N.E., Room&#160;1580,
    Washington,&#160;D.C. 20549. You may also obtain copies of these
    documents at prescribed rates by writing to the SEC. Please call
    the SEC at
    <FONT style="white-space: nowrap">1-800-SEC-0330</FONT>
    for further information on the operation of its Public Reference
    Room.
</DIV>
<A name='611'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Incorporation
    of certain documents by reference
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The SEC allows us to &#147;incorporate by reference&#148; into
    this prospectus supplement the information we have filed with
    the SEC. The information we incorporate by reference into this
    prospectus supplement is an important part of this prospectus
    supplement. Any statement in a document we incorporate by
    reference into this prospectus supplement or the accompanying
    prospectus will be considered to be modified or superseded to
    the extent a statement contained in this prospectus supplement
    or any other subsequently filed document that is incorporated by
    reference into this prospectus supplement modifies or supersedes
    that statement. The modified or superseded statement will not be
    considered to be a part of this prospectus supplement or
    accompanying prospectus, as applicable, except as modified or
    superseded.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We incorporate by reference into this prospectus supplement the
    information contained in the documents listed below, which is
    considered to be a part of this prospectus supplement:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="3%"></TD>
    <TD width="93%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    our Annual Report on
    <FONT style="white-space: nowrap">Form&#160;10-K</FONT>
    for the year ended December&#160;31, 2008, including any
    amendment filed for the purpose of updating such Annual Report;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    Our Quarterly Report on
    <FONT style="white-space: nowrap">Form&#160;10-Q</FONT>
    for the quarterly period ending March&#160;31, 2009;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    Our Current Reports on
    <FONT style="white-space: nowrap">Form&#160;8-K</FONT>
    filed with the SEC on January&#160;7, 2009, January&#160;22,
    2009, January&#160;29, 2009, February&#160;5, 2009,
    April&#160;28, 2009 and June&#160;10, 2009;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    Our Proxy Statement of Schedule&#160;14A filed with the SEC on
    April&#160;23, 2009;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    <FONT style="font-family: Wingdings; font-variant: normal">&#216;</FONT>&#160;
</TD>
    <TD align="left">
    the description of our common stock and related rights contained
    in our registration statements on
    <FONT style="white-space: nowrap">Form&#160;8-A</FONT>
    (file no.
    <FONT style="white-space: nowrap">001-33958)</FONT>
    filed under the Exchange Act, including any amendment or report
    filed for the purpose of updating such description.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We also incorporate by reference all documents filed pursuant to
    Sections&#160;13(a), 13(c), 14 or 15(d) of the Exchange Act
    after the date of this prospectus supplement and prior to the
    termination of this offering; provided, however, that we are not
    incorporating any information furnished under Item&#160;2.02 or
    Item&#160;7.01 of any current report on
    <FONT style="white-space: nowrap">Form&#160;8-K</FONT>
    we may subsequently file.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Statements made in this prospectus supplement or the
    accompanying prospectus or in any document incorporated by
    reference in this prospectus supplement or the accompanying
    prospectus as to the contents of any contract or other document
    referred to herein or therein are not necessarily complete, and
    in each instance reference is made to the copy of such contract
    or other document filed as an exhibit to the documents
    incorporated by reference, each such statement being qualified
    in all material respects by such reference.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    You may request a copy of these filings, at no cost, by writing
    or telephoning us at the following address:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">RXi
    Pharmaceuticals Corporation<BR>
    60 Prescott Street<BR>
    Worcester, MA 01650<BR>
    Attention: Investor Relations<BR>
    Phone:
    <FONT style="white-space: nowrap">(508)&#160;767-3861</FONT>
    </FONT>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Copies of these filings are also available, without charge,
    through the &#147;Investor Relations&#148; section of our
    website (www.rxipharma.com) as soon as reasonably practicable
    after they are filed electronically with the SEC. The
    information contained on our website is not a part of this
    prospectus.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-24</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->
<P></P>
<A name='612'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Legal matters
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The validity of the issuance of the securities offered hereby
    will be passed upon for us by Ropes&#160;&#038; Gray LLP.
    Weinstein Smith LLP is counsel for the placement agent in
    connection with this offering.
</DIV>
<A name='613'>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 16pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Experts
    </FONT>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
</A>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    BDO Seidman, LLP, independent registered public accounting firm,
    has audited our consolidated financial statements included in
    our Annual Report on
    <FONT style="white-space: nowrap">Form&#160;10-K</FONT>
    for the year ended December&#160;31, 2008, as set forth in their
    report, which is incorporated by reference in the prospectus and
    elsewhere in this registration statement. Our consolidated
    financial statements are incorporated by reference in reliance
    on BDO Seidman, LLP&#146;s report, given on their authority as
    experts in accounting and auditing.
</DIV>
<P>

<DIV style="font-size: 0pt; margin-left: 0%; width: 100%;  align: left; border-bottom: 1pt solid #000000"></DIV><!-- callerid=999 iwidth=456 length=0 -->

<DIV align="right" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 8pt">S-25</FONT></B>
</DIV>
<P></P>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B>PROSPECTUS</B>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B><FONT style="font-size: 20pt">RXI PHARMACEUTICALS
    CORPORATION</FONT></B>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 12pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="50%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="2%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="48%">&nbsp;</TD>	<!-- colindex=02 type=maindata -->
</TR>
<!-- Table Width Row END -->
<TR valign="bottom">
<TD align="center" valign="top">
<DIV style="text-indent: -12pt; margin-left: 12pt">
    <B>Primary Securities<BR>
    </B>$30,000,000<BR>
    Common Stock<BR>
    Preferred Stock<BR>
    Warrants<BR>
    Debt Securities
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD align="center" valign="top">
    <B>Secondary Securities<BR>
    </B>500,000 Shares<BR>
    of Common Stock
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<CENTER style="font-size: 1pt; width: 18%; border-bottom: 1pt solid #000000"></CENTER><!-- callerid=999 iwidth=456 length=84 -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    This prospectus relates to both (i)&#160;shares of our own
    securities which we may offer for sale from time to time, and
    which may take the form of equity, debt or warrants (the
    &#147;Primary Securities&#148;), and (ii)&#160;shares of our
    common stock being offered for resale by CytRx Corporation, or
    CytRx (the &#147;Secondary Securities&#148;).
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">The
    Primary Securities Offering</FONT></B>
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may offer the Primary Securities to the public from time to
    time in one or more series or issuances:
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    shares of our common stock;
</TD>
</TR>


<TR style="line-height: 3pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    shares of preferred stock;
</TD>
</TR>


<TR style="line-height: 3pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    warrants to purchase shares of our common stock, preferred stock
    <FONT style="white-space: nowrap">and/or</FONT> debt
    securities;&#160;or
</TD>
</TR>


<TR style="line-height: 3pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    debt securities consisting of debentures, notes or other
    evidences of indebtedness.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    This prospectus provides a general description of the Primary
    Securities we may offer. Each time we sell Primary Securities,
    we will provide specific terms of the securities offered in a
    supplement to this prospectus. Such a prospectus supplement may
    also add, update or change information contained in this
    prospectus. This prospectus may not be used to consummate a sale
    of Primary Securities unless accompanied by the applicable
    prospectus supplement. You should read both this prospectus and
    the applicable prospectus supplement together with additional
    information described under the heading &#147;Where You Can Find
    More Information&#148; before you make your investment decision.
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will sell these Primary Securities directly to our
    stockholders or to purchasers or through agents on our behalf or
    through underwriters or dealers as designated from time to time.
    If any agents or underwriters are involved in the sale of any of
    these Primary Securities, the applicable prospectus supplement
    will provide the names of the agents or underwriters and any
    applicable fees, commissions or discounts.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">The
    Secondary Securities Offering</FONT></B>
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx is offering to sell up to 500,000 shares of our common
    stock, which we refer to in this Prospectus as Secondary
    Securities. You should read this prospectus together with
    additional information described under the heading &#147;Where
    You Can Find More Information&#148; before you make your
    investment decision.
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The selling stockholder may offer the Secondary Securities from
    time to time to or through brokers, dealers or other agents, or
    directly to other purchasers, in one or more market transactions
    or private transactions at prevailing market or at negotiated
    prices. Brokers or dealers effecting transactions in Secondary
    Securities should confirm that the Secondary Securities are
    registered under applicable state law or that an exemption from
    registration is available.
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will not receive any proceeds from any sale of the Secondary
    Securities.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">General
    Information</FONT></B>
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our common stock is traded on the Nasdaq Capital Market under
    the symbol &#147;RXII.&#148; On April&#160;30, 2009, the closing
    price of our common stock was $4.55.
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    As of April&#160;30, 2009, the aggregate market value of our
    outstanding common stock held by non-affiliates was
    approximately $33,791,371 based on 13,821,629&#160;shares of
    outstanding common stock, of which approximately
    7,426,675&#160;shares are held by non-affiliates, and a per
    share price of $4.55 based on the closing sale price of our
    common stock on April&#160;30, 2009. As of the date hereof, we
    have not offered any securities pursuant to General
    Instruction&#160;I.B.6 of
    <FONT style="white-space: nowrap">Form&#160;S-3</FONT>
    during the prior 12 calendar month period that ends on and
    includes the date hereof.
</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 5%; font-size: 12pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B>Investing in our securities involves risks. See &#147;Risk
    Factors&#148; on page&#160;2</B>.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<CENTER style="font-size: 1pt; width: 18%; border-bottom: 1pt solid #000000"></CENTER><!-- callerid=999 iwidth=456 length=84 -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <B>Neither the Securities and Exchange Commission nor any state
    securities commission has approved or disapproved of these
    securities or passed upon the adequacy or accuracy of this
    prospectus. Any representation to the contrary is a criminal
    offense.</B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<CENTER style="font-size: 1pt; width: 18%; border-bottom: 1pt solid #000000"></CENTER><!-- callerid=999 iwidth=456 length=84 -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV style="margin-top: 3pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The date of this prospectus is May&#160;22, 2009
</DIV>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">TABLE OF
    CONTENTS</FONT></B>
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>
<DIV align="left">
<!-- TOC -->
</DIV>

<DIV align="left">
<A name="tocpage"></A>
</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="97%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="2%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=02 type=quadleft -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=02 type=maindata -->
    <TD width="1%">&nbsp;</TD>	<!-- colindex=02 type=quadright -->
</TR>
<!-- Table Width Row END -->
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Page</B>
</TD>
</TR>
<TR style="line-height: 3pt; font-size: 1pt">
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#101'>About this Prospectus</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#102'>Our Company</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    1
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#103'>Risk Factors</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    2
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#104'>Forward-Looking Statements</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    2
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#105'>Use of Proceeds</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    3
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#106'>Plan of Distribution</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    5
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#107'>Description of Common Stock</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    7
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#108'>Description of Preferred Stock</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    8
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#109'>Description of Warrants</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    9
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#110'>Description of Debt Securities</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    10
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#111'>Where You Can Find More Information</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    17
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#112'>Incorporation of Certain Documents by
    Reference</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    17
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#113'>Legal Matters</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    18
</TD>
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    <A HREF='#114'>Experts</A>
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD>&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    18
</TD>
<TD>&nbsp;
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV align="left">
<!-- /TOC -->
</DIV>
<A name='101'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">ABOUT
    THIS PROSPECTUS</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The securities described in this prospectus are part of a
    registration statement that we filed with the Securities and
    Exchange Commission, or the SEC, using a &#147;shelf&#148;
    registration process. Under this shelf registration process, we
    may offer to sell any combination of the Primary Securities
    described in this prospectus in one or more offerings up to a
    total dollar amount of $30,000,000.00. This prospectus provides
    you with a general description of the Primary Securities we may
    offer. Each time we sell Primary Securities under this shelf
    registration, we will provide a prospectus supplement that will
    contain specific information about the terms of such offering.
    The prospectus supplement may also add, update or change
    information contained in this prospectus. Separate from the
    Primary Securities, we are also registering for resale up to
    500,000&#160;shares of the Secondary Securities owned by CytRx,
    which they may sell from time to time in accordance with this
    prospectus. You should read both this prospectus and any
    applicable prospectus supplement, including all documents
    incorporated herein by reference, together with additional
    information described under &#147;Where You Can Find More
    Information&#148; below.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have not authorized any dealer, agent or other person to give
    any information or to make any representation other than those
    contained or incorporated by reference in this prospectus and
    any accompanying prospectus supplement. You must not rely upon
    any information or representation not contained or incorporated
    by reference in this prospectus or an accompanying prospectus
    supplement. This prospectus and the accompanying prospectus
    supplement, if any, do not constitute an offer to sell or the
    solicitation of an offer to buy any securities other than the
    registered securities to which they relate, nor do this
    prospectus and any accompanying prospectus supplement constitute
    an offer to sell or the solicitation of an offer to buy
    securities in any jurisdiction to any person to whom it is
    unlawful to make such offer or solicitation in such
    jurisdiction. You should not assume that the information
    contained in this prospectus and any accompanying prospectus
    supplement, if any, is accurate on any date subsequent to the
    date set forth on the front of the document or that any
    information we have incorporated by reference is correct on any
    date subsequent to the date of the document incorporated by
    reference, even though this prospectus and any accompanying
    prospectus supplement is delivered or securities are sold on a
    later date.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Unless the context otherwise requires, &#147;RXi,&#148; the
    &#147;Company,&#148; &#147;we,&#148; &#147;us,&#148;
    &#147;our&#148; and similar names refer to RXi Pharmaceuticals
    Corporation.
</DIV>

<P align="left" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<A name='102'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">OUR
    COMPANY</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are a discovery-stage biopharmaceutical company pursuing
    proprietary therapeutics based on RNA interference, or RNAi, a
    naturally occurring cellular mechanism for the regulation of
    gene expression that has the potential to be harnessed to
    selectively inhibit the activity of any human gene. As described
    in Kim and Rossi&#146;s review published in March 2007 in
    <I>Nature Reviews Genetics, </I>it is believed that this
    inhibition may potentially treat human diseases by &#147;turning
    off&#148; genes that lead to disease. While no therapeutic RNAi
    products have yet been approved, there has been significant
    growth in the field of RNAi development and potential
    therapeutic applications. This growth is driven by the potential
    ability to use RNAi to rapidly develop lead compounds that
    specifically and selectively inhibit a target gene.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We intend to focus our internal research and development
    programs on certain inflammatory and metabolic diseases, and to
    pursue other therapeutic areas with potential partners. By
    utilizing our expertise in RNAi and the RNAi technology platform
    we have built, we believe we will be able to discover lead
    compounds and move them into clinical development more
    efficiently than traditional drug discovery approaches.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our proprietary technology platform is comprised of two main
    components:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    Novel RNAi compounds, referred to as
    rxRNA<SUP style="font-size: 85%; vertical-align: top"><FONT style="font-variant: SMALL-CAPS">tm</FONT></SUP>

    compounds, that are distinct from, and we believe convey
    significant advantages over classic siRNA
    (conventionally-designed &#147;small interfering RNA&#148;
    compounds), and offer many of the properties that we believe are
    important to the clinical development of RNAi-based drugs. We
    have developed several unique forms of rxRNA compounds, each of
    which has been shown to be highly potent and, we believe,
    unencumbered by the intellectual property rights of others.
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    Multiple technologies to potentially enable the delivery of our
    rxRNA compounds via local, systemic and oral administration. In
    October 2008, we exclusively licensed intellectual property
    rights to novel technology that we believe should enable the
    oral delivery of rxRNA compounds to macrophages, which are key
    inflammatory cells involved in the progression of various
    inflammatory diseases, resulting in efficient delivery of our
    rxRNA compounds to sites of inflammation. Oral administration is
    preferred to injection, the route used to administer current
    drugs for inflammation, as a method of administering a drug. We
    believe this technology provides us with a potential competitive
    advantage in the delivery of RNAi therapeutics, and is a major
    focus of our R&#038;D activities. We are also pursuing other
    potential approaches for the local and systemic delivery of
    rxRNA compounds to other targets of interest, such as certain
    targets involved in metabolic disease.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We intend to use our RNAi technology platform and our expertise
    in RNAi to identify lead compounds and advance towards
    pre-clinical and clinical development programs in the following
    therapeutic areas:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    <I>Inflammatory disease.</I>&#160;&#160;Our lead program targets
    genes involved in inflammation, which is responsible for a
    variety of diseases representing significant unmet medical needs
    and large market opportunities. Our initial targets include
    validated gene targets related to the TNFa pathway, which is
    involved in many diseases, including, for example, rheumatoid
    arthritis, Crohn&#146;s disease and psoriasis, and our follow-on
    programs involve other novel gene targets that are implicated in
    atherosclerosis, type 2 diabetes and other inflammatory diseases.
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    <I>Metabolic disease.</I>&#160;&#160;We have two primary efforts
    in metabolic disease. First, we are targeting an undisclosed
    gene thought to be responsible for elevated cholesterol. We have
    also in-licensed intellectual property developed by
    Dr.&#160;Michael Czech (one of our scientific co-founders and
    scientific advisory board members) on genes that appear to be
    important regulators of metabolism. Studies conducted in
    Dr.&#160;Czech&#146;s laboratory at the University of
    Massachusetts Medical School (UMMS) and by others at Imperial
    College of London have demonstrated that inactivation of one of
    these genes, called RIP140, can cause fat cells to metabolize
    rather than store fat. Mice in these studies that did not
    express RIP140 remained lean and non-diabetic even when
    maintained on a high-fat diet. We are currently designing RNAi
    compounds targeting RIP140 as a potential treatment for obesity
    and obesity-related type 2 diabetes.
</TD>
</TR>

</TABLE>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    1
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    <I>Additional indications.</I>&#160;&#160;There are many
    well-studied genes that have been associated with numerous
    diseases but have been difficult to target with conventional
    medicinal chemistry. We believe RNAi technology may play an
    important role in targeting these genes and potentially treating
    the related diseases. With that in mind, RXi may also pursue
    additional disease areas with the goal of creating multiple
    clinical development programs, either by our company alone or in
    partnership with pharmaceutical or larger biotechnology
    companies.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We believe that we possess a strong intellectual property
    portfolio. We have secured exclusive and nonexclusive licenses
    from both academic institutions and commercial entities to
    certain issued and pending patents and patent applications
    covering RNAi technologies in the following three categories:
    (i)&#160;therapeutic targets, (ii)&#160;chemistry and
    configurations of RNAi compounds and (iii)&#160;delivery of RNAi
    compounds within the body. We have also filed patents based on
    our internal discoveries in the each of the areas mentioned
    above.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our principal executive offices are located at 60 Prescott
    Street, Worcester, MA 01605, and our phone number is
    <FONT style="white-space: nowrap">(508)&#160;767-3861.</FONT>
</DIV>
<A name='103'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">RISK
    FACTORS</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Investing in our securities involves risk. You should consider
    the risks, uncertainties and assumptions discussed under the
    heading &#147;Risk Factors&#148; in our Annual Report on
    <FONT style="white-space: nowrap">Form&#160;10-K</FONT>
    for the fiscal year ended December&#160;31, 2008 filed on
    March&#160;18, 2009 with the Securities and Exchange Commission
    (&#147;SEC&#148;), which is incorporated herein by reference,
    and may be amended, supplemented or superseded from time to time
    by other reports we file with the SEC in the future. The risks
    and uncertainties we have described are not the only ones we
    face. Additional risks and uncertainties not presently known to
    us or that we currently deem immaterial may also affect our
    operations. If any of these risks were to occur, our business,
    financial condition, and results of operations could be severely
    harmed. This could cause the trading price of our common stock
    to decline, and you could lose all or part of your investment.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In addition, any prospectus supplement applicable to each
    offering of our Primary Securities will contain a discussion of
    the risks applicable to such an investment in us. Prior to
    making a decision about investing in our Primary Securities, you
    should carefully consider the specific factors discussed under
    the heading &#147;Risk Factors&#148; in the applicable
    prospectus supplement, together with all of the other
    information contained or incorporated by reference in such
    prospectus supplement or appearing or incorporated by reference
    in this prospectus.
</DIV>
<A name='104'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">FORWARD-LOOKING
    STATEMENTS</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    This prospectus, any prospectus supplement and the other
    documents we have filed with the SEC that are incorporated
    herein by reference contain forward-looking statements within
    the meaning of the Private Securities Litigation Reform Act of
    1995 that involve risks and uncertainties, as well as
    assumptions that, if they never materialize or prove incorrect,
    could cause the results of RXi to differ materially from those
    expressed or implied by such forward-looking statements. All
    statements other than statements of historical fact are
    statements that could be deemed forward-looking statements,
    including any projections of financing needs, revenue, expenses,
    earnings or losses from operations, or other financial items;
    any statements of the plans, strategies and objectives of
    management for future operations; any statements concerning
    product research, development and commercialization plans and
    timelines; any statements regarding safety and efficacy of
    product candidates; any statements of expectation or belief; and
    any statements of assumptions underlying any of the foregoing.
    In addition, forward-looking statements may contain the words
    &#147;believe,&#148; &#147;anticipate,&#148; &#147;expect,&#148;
    &#147;estimate,&#148; &#147;intend,&#148; &#147;plan,&#148;
    &#147;project,&#148; &#147;will be,&#148; &#147;will
    continue,&#148; &#147;will result,&#148; &#147;seek,&#148;
    &#147;could,&#148; &#147;may,&#148; &#147;might,&#148; or any
    variations of such words or other words with similar meanings.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Given these uncertainties, you should not place undue reliance
    on these forward-looking statements. You should read this
    prospectus, any supplements to this prospectus and the documents
    that we reference in this prospectus with the understanding that
    our actual future results may be materially different from what
    we
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    2
</DIV><!-- END PAGE WIDTH -->
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    expect. Except as required by law, we do not undertake any
    obligation to update or revise any forward-looking statements
    contained in this prospectus and any supplements to this
    prospectus, whether as a result of new information, future
    events or otherwise.
</DIV>
<A name='105'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">USE OF
    PROCEEDS</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Primary
    Securities</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Except as otherwise provided in the applicable prospectus
    supplement, we intend to use the net proceeds from the sale of
    the Primary Securities covered by this prospectus for general
    corporate purposes, which may include working capital, capital
    expenditures, research and development expenditures, clinical
    trial expenditures, commercial expenditures, acquisitions of new
    technologies or businesses, and investments. Additional
    information on the use of net proceeds from the sale of Primary
    Securities covered by this prospectus may be set forth in any
    prospectus supplement relating to the specific offering.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Secondary
    Securities</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The net proceeds from any disposition of the Secondary
    Securities covered by this prospectus will be received by CytRx.
    We will not receive any of the proceeds from any such sale of
    the Secondary Securities offered by this prospectus.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will pay the costs and expenses relating to the offering by
    CytRx of the Secondary Securities, except that CytRx will bear
    any discounts and commissions relating to any sale of the
    Secondary Securities.
</DIV>

<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">SELLING
    STOCKHOLDER</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The following table sets forth information with respect to the
    beneficial ownership of our common stock by CytRx as of
    April&#160;30, 2009 after giving further effect to the offering
    of the Secondary Securities pursuant to this prospectus. The
    information shown does not give effect to the sale of any of the
    Primary Securities. Beneficial ownership is determined in
    accordance with SEC rules, and generally includes voting or
    investment power with respect to securities.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx, if it desires, may dispose of the Secondary Securities
    covered by this prospectus from time to time at such prices as
    it may choose. Before any stockholder other than CytRx may use
    this prospectus in connection with an offering of Secondary
    Securities, this prospectus must be amended or supplemented to
    include the name and number of Secondary Securities beneficially
    owned by the selling stockholder and the number of Secondary
    Securities to be offered. Any amended or supplemented prospectus
    also will disclose whether any selling stockholder named in that
    amended or supplemented prospectus has held any position, office
    or other material relationship with us or any of our
    predecessors or affiliates during the three years prior to the
    date of the amended or supplemented prospectus.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
<!-- Table Width Row BEGIN -->
<TR style="font-size: 1pt" valign="bottom">
    <TD width="33%">&nbsp;</TD>	<!-- colindex=01 type=maindata -->
    <TD width="2%">&nbsp;</TD>	<!-- colindex=02 type=gutter -->
    <TD width="7%" align="right">&nbsp;</TD>	<!-- colindex=02 type=lead -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=02 type=body -->
    <TD width="7%" align="left">&nbsp;</TD>	<!-- colindex=02 type=hang1 -->
    <TD width="3%">&nbsp;</TD>	<!-- colindex=03 type=gutter -->
    <TD width="2%" align="right">&nbsp;</TD>	<!-- colindex=03 type=lead -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=03 type=body -->
    <TD width="2%" align="left">&nbsp;</TD>	<!-- colindex=03 type=hang1 -->
    <TD width="3%">&nbsp;</TD>	<!-- colindex=04 type=gutter -->
    <TD width="7%" align="right">&nbsp;</TD>	<!-- colindex=04 type=lead -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=04 type=body -->
    <TD width="7%" align="left">&nbsp;</TD>	<!-- colindex=04 type=hang1 -->
    <TD width="3%">&nbsp;</TD>	<!-- colindex=05 type=gutter -->
    <TD width="6%" align="right">&nbsp;</TD>	<!-- colindex=05 type=lead -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=05 type=body -->
    <TD width="6%" align="left">&nbsp;</TD>	<!-- colindex=05 type=hang1 -->
    <TD width="3%">&nbsp;</TD>	<!-- colindex=06 type=gutter -->
    <TD width="2%" align="right">&nbsp;</TD>	<!-- colindex=06 type=lead -->
    <TD width="1%" align="right">&nbsp;</TD>	<!-- colindex=06 type=body -->
    <TD width="2%" align="left">&nbsp;</TD>	<!-- colindex=06 type=hang1 -->
</TR>
<!-- Table Width Row END -->
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom">
    <B>Beneficial Ownership Upon<BR>
    </B>
</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom">
    <B>Beneficial Ownership of<BR>
    </B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom">
    <B>Completion of this Offering<BR>
    </B>
</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom">
    <B>Selling Stockholder<BR>
    </B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom">
    <B>(Assuming all Shares<BR>
    </B>
</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Before this Offering</B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom">
    <B>Number of Shares<BR>
    </B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="7" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Offered are Sold)</B>
</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom" align="center">
<TD nowrap align="center" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Number of Shares</B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Percent</B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Being Offered</B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Number of Share</B>
</TD>
<TD>
&nbsp;
</TD>
<TD colspan="3" nowrap align="center" valign="bottom" style="border-bottom: 1px solid #000000">
    <B>Percent</B>
</TD>
</TR>
<TR style="line-height: 3pt; font-size: 1pt">
<TD>&nbsp;
</TD>
</TR>
<TR valign="bottom" style="background: #CCEEFF">
<TD nowrap align="left" valign="bottom">
<DIV style="text-indent: -10pt; margin-left: 10pt">
    CytRx Corporation
</DIV>
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    6,268,881
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    45.4
</TD>
<TD nowrap align="left" valign="bottom">
    %
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    500,000
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    5,768,881
</TD>
<TD nowrap align="left" valign="bottom">
&nbsp;
</TD>
<TD>
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
&nbsp;
</TD>
<TD nowrap align="right" valign="bottom">
    41.7
</TD>
<TD nowrap align="left" valign="bottom">
    %
</TD>
</TR>
</TABLE>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">

</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Arrangements
    with CytRx</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We were incorporated in April 2006 by CytRx and four founding
    members of our scientific advisory board for the purpose of
    pursuing the development or acquisition of RNAi-related
    technologies and assets. The President and Chief Executive
    Officer of CytRx, Steven A. Kriegsman, is a member of our Board
    of Directors. The Chairman of our Board of Directors, Sanford J.
    Hillsberg, is an attorney with TroyGould PC, which has
    represented CytRx since 2003.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have entered into the following agreements with CytRx.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    3
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 2%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Contribution
    Agreements</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    On January&#160;8, 2007, we entered into a contribution
    agreement with CytRx under which CytRx assigned and contributed
    to us substantially all of its RNAi-related technologies and
    assets. The assigned assets consisted primarily of CytRx&#146;s
    licenses from University of Massachusetts Medical School (UMMS)
    and from the Carnegie Institution of Washington relating to
    fundamental RNAi technologies, as well as equipment situated at
    CytRx&#146;s Worcester, Massachusetts, laboratory. In connection
    with the contribution, we issued to CytRx approximately 85% of
    our outstanding shares of common stock immediately following the
    issuance.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    On April&#160;30, 2007, we entered into another contribution
    agreement with CytRx under which CytRx contributed to us
    $17.0&#160;million in exchange for an additional
    3,273,292&#160;shares of our common stock. We used
    $2.0&#160;million of this amount to reimburse CytRx for the
    estimated amount of expenses that had been incurred by CytRx as
    of April&#160;30, 2007 pursuant to the January&#160;8, 2007
    reimbursement agreement described below.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 2%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Registration
    Rights Agreement</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    On April&#160;30, 2007, we also entered into a registration
    rights agreement with CytRx under which we agreed, upon
    CytRx&#146;s request, to use our best efforts to cause to be
    registered under the Securities Act the RXi shares originally
    issued to CytRx pursuant to our contribution agreements with
    CytRx. Pursuant to the registration rights agreement, we also
    granted to CytRx &#147;piggyback&#148; registration rights
    entitling CytRx to include its RXi shares in any registration
    statement filed by us with the SEC. The offer and sale of the
    Secondary Securities have been included in the registration
    statement of which this prospectus is a part pursuant to
    CytRx&#146;s exercise of its piggyback registration rights.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 2%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Reimbursement
    Agreements</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    On January&#160;8, 2007, we also entered into a letter agreement
    with CytRx under which we agreed to reimburse CytRx, following
    our initial funding, for all organizational and operational
    expenses incurred by CytRx in connection with our formation and
    initial operations, and to bear or reimburse CytRx for an
    allocable share of any investment banking fees, placement agent
    fees and other offering expenses incurred by CytRx in connection
    with our fundraising activities. In connection with the
    April&#160;30, 2007 contribution agreement with CytRx described
    above, we reimbursed CytRx in accordance with this letter
    agreement. There are no further payments or obligations owed in
    accordance with this letter agreement.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    On December&#160;27, 2007, we entered into a letter agreement
    with CytRx under which we and CytRx agreed to a
    &#147;fee-sharing&#148; arrangement for expenses arising from
    the preparation of the registration statement for our initial
    public offering, and our application for the listing of our
    common stock on the Nasdaq Capital Market. Pursuant to this
    agreement, we agreed to reimburse CytRx an amount equal to the
    sum of (i)&#160;$30,000 plus (ii)&#160;50% of the total relevant
    fees and expenses paid by CytRx to certain financial services
    professionals. Also under this agreement CytRx agreed to
    reimburse us 50% of the total relevant fees and expenses paid by
    us to our financial printer, our transfer agent and our legal
    counsel. There are no further payments or obligations owed in
    accordance with this letter agreement.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 2%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><I><FONT style="font-family: 'Times New Roman', Times">Stockholder
    and Preemptive Rights Agreement</FONT></I></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    On February&#160;15, 2007, we entered into a letter agreement
    with CytRx and certain of our current stockholders. Under this
    letter agreement, we agreed to grant to CytRx preemptive rights
    to acquire any new securities that we propose to sell or issue
    so that CytRx may maintain its percentage ownership of us. The
    preemptive rights will expire on January&#160;8, 2012, or such
    earlier time at which CytRx owns less than 10% of our
    outstanding common stock. Under this letter agreement, CytRx
    also undertakes to vote its shares of our stock in the election
    of our directors and dispose of their shares of our stock in
    accordance with the terms of its letter agreement with UMMS.
    CytRx has further agreed in this letter agreement to approve of
    actions that may be adopted and recommended by our Board of
    Directors to facilitate any future financing. We amended this
    letter agreement on July&#160;28, 2008 to adjust certain
    non-material terms.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    4
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<A name='106'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">PLAN OF
    DISTRIBUTION</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Primary
    Securities</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may sell Primary Securities in any of the ways described
    below or in any combination:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to or through underwriters or dealers;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    through one or more agents;&#160;or
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    directly to purchasers or to a single purchaser.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The distribution of the Primary Securities may be effected from
    time to time in one or more transactions:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    at a fixed price, or prices, which may be changed from time to
    time;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    at market prices prevailing at the time of sale;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    at prices related to such prevailing market prices;&#160;or
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    at negotiated prices.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Each prospectus supplement will describe the method of
    distribution of the Primary Securities and any applicable
    restrictions.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The prospectus supplement with respect to the Primary Securities
    of a particular series will describe the terms of the offering
    of the Primary Securities, including the following:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the name or names of any underwriters, dealers or agents and the
    amounts of Primary Securities underwritten or purchased by each
    of them;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the public offering price of the Primary Securities and the
    proceeds to us and any discounts, commissions or concessions
    allowed or reallowed or paid to dealers;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any securities exchanges on which the Primary Securities may be
    listed.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Any offering price and any discounts or concessions allowed or
    reallowed or paid to dealers may be changed from time to time.
    Under no circumstances will any fees, discounts, commissions or
    concessions received by any FINRA member or independent
    broker-dealer exceed eight&#160;percent of the gross proceeds to
    us in any offering in the United States of the Primary
    Securities covered by the prospectus.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Only the agents or underwriters named in each prospectus
    supplement are agents or underwriters in connection with the
    Primary Securities being offered thereby.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may authorize underwriters, dealers or other persons acting
    as our agents to solicit offers by certain institutions to
    purchase Primary Securities from us pursuant to delayed delivery
    contracts providing for payment and delivery on the date stated
    in each applicable prospectus supplement. Each contract will be
    for an amount not less than, and the aggregate amount of Primary
    Securities sold pursuant to such contracts shall not be less nor
    more than, the respective amounts stated in each applicable
    prospectus supplement. Institutions with whom the contracts,
    when authorized, may be made include commercial and savings
    banks, insurance companies, pension funds, investment companies,
    educational and charitable institutions and other institutions,
    but shall in all cases be subject to our approval. Delayed
    delivery contracts will be subject only to those conditions set
    forth in each applicable prospectus supplement, and each
    prospectus supplement will set forth any commissions we pay for
    solicitation of these contracts.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Agents, underwriters and other third parties described above may
    be entitled to indemnification by us against certain civil
    liabilities, including liabilities under the Securities Act of
    1933, or to contribution from us with respect to payments which
    the agents, underwriters or other third parties may be required
    to make in respect thereof. Agents, underwriters and such other
    third parties may be customers of, engage in transactions with,
    or perform services for us in the ordinary course of business.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    5
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    One or more firms, referred to as &#147;remarketing firms,&#148;
    may also offer or sell the Primary Securities, if a prospectus
    supplement so indicates, in connection with a remarketing
    arrangement upon their purchase. Remarketing firms will act as
    principals for their own accounts or as our agents. These
    remarketing firms will offer or sell the Primary Securities in
    accordance with the terms of the Primary Securities. Each
    prospectus supplement will identify and describe any remarketing
    firm and the terms of its agreement, if any, with us and will
    describe the remarketing firm&#146;s compensation. Remarketing
    firms may be deemed to be underwriters in connection with the
    Primary Securities they remarket. Remarketing firms may be
    entitled under agreements that may be entered into with us to
    indemnification by us against certain civil liabilities,
    including liabilities under the Securities Act of 1933, and may
    be customers of, engage in transactions with or perform services
    for us in the ordinary course of business.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Certain underwriters may use this prospectus and any
    accompanying prospectus supplement for offers and sales related
    to market-making transactions in the Primary Securities. These
    underwriters may act as principal or agent in these
    transactions, and the sales will be made at prices related to
    prevailing market prices at the time of sale.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The Primary Securities may be new issues of Primary Securities
    and may have no established trading market. The Primary
    Securities may or may not be listed on a securities exchange.
    Underwriters may make a market in these Primary Securities, but
    will not be obligated to do so and may discontinue any market
    making at any time without notice. We can make no assurance as
    to the liquidity of, or the existence of trading markets for,
    any of the Primary Securities.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Certain persons participating in an offering may engage in
    overallotment, stabilizing transactions, short covering
    transactions and penalty bids in accordance with rules and
    regulations under the Securities Exchange Act of 1934.
    Overallotment involves sales in excess of the offering size,
    which create a short position. Stabilizing transactions permit
    bids to purchase the underlying security so long as the
    stabilizing bids do not exceed a specified maximum. Short
    covering transactions involve purchases of the Primary
    Securities in the open market after the distribution is
    completed to cover short positions. Penalty bids permit the
    underwriters to reclaim a selling concession from a dealer when
    the Primary Securities originally sold by the dealer are
    purchased in a short covering transaction to cover short
    positions. Those activities may cause the price of the Primary
    Securities to be higher than it would otherwise be. If
    commenced, the underwriters may discontinue any of the
    activities at any time.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Secondary
    Securities</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx may, from time to time, sell, transfer, or otherwise
    dispose of any or all of its Secondary Securities on any stock
    exchange, market, or trading facility on which the shares are
    traded or in private transactions. These dispositions may be at
    fixed prices, at prevailing market prices at the time of sale,
    at prices related to the prevailing market price, at varying
    prices determined at the time of sale, or at negotiated prices.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx may use any one or more of the following methods when
    disposing of Secondary Securities:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    ordinary brokerage transactions and transactions in which the
    broker-dealer solicits purchasers;
</TD>
</TR>

<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    block trades in which the broker-dealer will attempt to sell the
    shares as agent, but may position and resell a portion of the
    block as principal to facilitate the transaction;
</TD>
</TR>

<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    purchases by a broker-dealer as principal and resale by the
    broker-dealer for its account;
</TD>
</TR>

<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    an exchange distribution in accordance with the rules of the
    applicable exchange;
</TD>
</TR>

<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    privately negotiated transactions;
</TD>
</TR>

<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    broker-dealers may agree with CytRx to sell a specified number
    of such shares at a stipulated price per share; or
</TD>
</TR>

<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    a combination of any such methods of sale.
</TD>
</TR>

</TABLE>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    6
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The aggregate proceeds to CytRx from any sale of the Secondary
    Securities offered by it will be the purchase price of the
    common stock less discounts or commissions, if any. CytRx
    reserves the right to accept and, together with its agents from
    time to time, to reject, in whole or in part, any proposed
    purchase of Secondary Securities to be made directly or through
    agents. We will not receive any of the proceeds from any such
    sale.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx also may resell all or a portion of the Secondary
    Securities in open market transactions in reliance upon
    Rule&#160;144 promulgated under the Securities Act, provided
    that it meets the criteria and conform to the requirements of
    that rule.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    CytRx and any broker-dealers or agents that participate in the
    sale of the Secondary Securities may be deemed to be
    &#147;underwriters&#148; within the meaning of
    Section&#160;2(11) of the Securities Act. Any discounts,
    commissions, concessions or profit they earn on any resale of
    the shares may be underwriting discounts and commissions under
    the Securities Act. CytRx is subject to the prospectus delivery
    requirements of the Securities Act.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have agreed with CytRx to keep the registration statement, of
    which this prospectus constitutes a part, effective for one
    year, subject to certain extensions, or earlier if all of the
    Secondary Shares are sold prior to the end of such period.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will pay the costs and expenses relating to the offering by
    CytRx of the Secondary Securities, except that CytRx will bear
    any discounts and commissions relating to any sale of the
    Secondary Securities.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Prior
    Proposed Offering</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Prior to filing the registration statement of which this
    prospectus is a part, we explored the possibility of conducting
    a private placement of our common stock with certain prospective
    investors. The proposed private placement sought to raise up to
    approximately $14,000,000 in gross proceeds. We did not accept
    any offers to buy our securities and none of our securities were
    sold in the proposed private placement. We terminated all
    offering activity related to the proposed private placement on
    April 29, 2009. This prospectus supersedes any offering
    materials used in the proposed private placement.
</DIV>
<A name='107'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">DESCRIPTION
    OF COMMON STOCK</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The following summary of the terms of our common stock is
    subject to and qualified in its entirety by reference to our
    charter and by-laws, copies of which are on file with the SEC as
    exhibits to previous SEC filings. Please refer to &#147;Where
    You Can Find More Information&#148; below for directions on
    obtaining these documents.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    As of April&#160;30, 2009, we are authorized to issue
    50,000,000&#160;shares of common stock. As of April&#160;30,
    2009, we had 13,821,629&#160;shares of common stock outstanding.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">General</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The holders of our common stock are entitled to one vote for
    each share on all matters voted on by stockholders, including
    elections of directors, and, except as otherwise required by law
    or provided in any resolution adopted by our board with respect
    to any series of preferred stock, the holders of such shares
    possess all voting power. Our certificate of incorporation does
    not provide for cumulative voting in the election of directors.
    Subject to any preferential rights of any outstanding series of
    our preferred stock created by our board from time to time, the
    holders of common stock are entitled to such dividends as may be
    declared from time to time by our board from funds available
    therefore and upon liquidation are entitled to receive pro rata
    all assets available for distribution to such holders. Our
    common stock is not redeemable. For a more complete discussion
    of our dividend policy, please see &#147;Dividend Policy.&#148;
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The holders of our common stock, other than CytRx, have no
    preemptive rights. The rights, preferences and privileges of
    holders of common stock are subject to, and may be adversely
    affected by, the rights of the holders of shares of any series
    of preferred stock which we may designate and issue in the
    future. Additionally,
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    7
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    under our agreement with CytRx and our current stockholders,
    with some exceptions, CytRx has preemptive rights to acquire a
    portion of any new securities sold or issued by us so as to
    maintain their percentage beneficial ownership of us at the time
    of such sale or issuance.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Transfer
    Agent and Registrar</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The transfer agent and registrar for our common stock is
    Computershare Trust&#160;Company, N.A.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Nasdaq
    Capital Market</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Our common stock is listed for quotation on the Nasdaq Capital
    Market under the symbol &#147;RXII.&#148;
</DIV>
<A name='108'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">DESCRIPTION
    OF PREFERRED STOCK</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are authorized to issue up to 5,000,000&#160;shares of
    preferred stock, par value $0.0001 per share. Our board of
    directors, without further action by the holders of our common
    stock, may issue shares of our preferred stock. Our board is
    vested with the authority to fix by resolution the designations,
    preferences and relative, participating, optional or other
    special rights, and such qualifications, limitations or
    restrictions thereof, including, without limitation, redemption
    rights, dividend rights, liquidation preferences and conversion
    or exchange rights of any class or series of preferred stock,
    and to fix the number of classes or series of preferred stock,
    the number of shares constituting any such class or series and
    the voting powers for each class or series.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The authority possessed by our board to issue preferred stock
    could potentially be used to discourage attempts by third
    parties to obtain control of RXi through a merger, tender offer,
    proxy contest or otherwise by making such attempts more
    difficult or more costly. Our board may issue preferred stock
    with voting rights or conversion rights that, if exercised,
    could adversely affect the voting power of the holders of common
    stock. There are no current agreements or understandings with
    respect to the issuance of preferred stock.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If we offer a specific class or series of preferred stock under
    this prospectus, we will describe the terms of the preferred
    stock in the prospectus supplement for such offering and will
    file a copy of the certificate establishing the terms of the
    preferred stock with the SEC. To the extent required, this
    description will include:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the title and stated value;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the number of shares offered, the liquidation preference per
    share and the purchase price;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the dividend rate(s), period(s)
    <FONT style="white-space: nowrap">and/or</FONT>
    payment date(s), or method(s) of calculation for such dividends;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    whether dividends will be cumulative or non-cumulative and, if
    cumulative, the date from which dividends will accumulate;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the procedures for any auction and remarketing, if any;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the provisions for a sinking fund, if any;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the provisions for redemption, if applicable;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any listing of the preferred stock on any securities exchange or
    market;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    whether the preferred stock will be convertible into our common
    stock, and, if applicable, the conversion price (or how it will
    be calculated) and conversion period;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    whether the preferred stock will be exchangeable into debt
    securities, and, if applicable, the exchange price (or how it
    will be calculated) and exchange period;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    voting rights, if any, of the preferred stock;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    a discussion of any material U.S.&#160;federal income tax
    considerations applicable to the preferred stock;
</TD>
</TR>

</TABLE>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    8
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the relative ranking and preferences of the preferred stock as
    to dividend rights and rights upon liquidation, dissolution or
    winding up of the affairs of the Company;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any material limitations on issuance of any class or series of
    preferred stock ranking senior to or on a parity with the series
    of preferred stock as to dividend rights and rights upon
    liquidation, dissolution or winding up of the Company.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The preferred stock offered by this prospectus, when issued,
    will not have, or be subject to, any preemptive or similar
    rights.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Transfer
    Agent and Registrar</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The transfer agent and registrar for any series or class of
    preferred stock will be set forth in each applicable prospectus
    supplement.
</DIV>
<A name='109'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">DESCRIPTION
    OF WARRANTS</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    As of April&#160;30, 2009, we had 332,500 warrants outstanding
    to purchase shares of our common stock. We may issue warrants to
    purchase shares of our common stock, preferred stock
    <FONT style="white-space: nowrap">and/or</FONT> debt
    securities in one or more series together with other securities
    or separately, as described in each applicable prospectus
    supplement. Below is a description of certain general terms and
    provisions of the warrants that we may offer. Particular terms
    of the warrants will be described in the applicable warrant
    agreements and the applicable prospectus supplement for the
    warrants.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The applicable prospectus supplement will contain, where
    applicable, the following terms of and other information
    relating to the warrants:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the specific designation and aggregate number of, and the price
    at which we will issue, the warrants;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the currency or currency units in which the offering price, if
    any, and the exercise price are payable;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the designation, amount and terms of the securities purchasable
    upon exercise of the warrants;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    if applicable, the exercise price for shares of our common stock
    and the number of shares of common stock to be received upon
    exercise of the warrants;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    if applicable, the exercise price for shares of our preferred
    stock, the number of shares of preferred stock to be received
    upon exercise, and a description of that class or series of our
    preferred stock;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    if applicable, the exercise price for our debt securities, the
    amount of our debt securities to be received upon exercise, and
    a description of that series of debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the date on which the right to exercise the warrants will begin
    and the date on which that right will expire or, if the warrants
    may not be continuously exercised throughout that period, the
    specific date or dates on which the warrants may be exercised;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    whether the warrants will be issued in fully registered form or
    bearer form, in definitive or global form or in any combination
    of these forms, although, in any case, the form of a warrant
    included in a unit will correspond to the form of the unit and
    of any security included in that unit;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any applicable material U.S.&#160;federal income tax
    consequences;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the identity of the warrant agent for the warrants and of any
    other depositaries, execution or paying agents, transfer agents,
    registrars or other agents;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the proposed listing, if any, of the warrants or any securities
    purchasable upon exercise of the warrants on any securities
    exchange;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    if applicable, the date from and after which the warrants and
    the common stock, preferred stock
    <FONT style="white-space: nowrap">and/or</FONT> debt
    securities will be separately transferable;
</TD>
</TR>

</TABLE>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    9
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    if applicable, the minimum or maximum amount of the warrants
    that may be exercised at any one time;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    information with respect to book-entry procedures, if any;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the anti-dilution provisions of the warrants, if any;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any redemption or call provisions;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    whether the warrants are to be sold separately or with other
    securities as parts of units;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any additional terms of the warrants, including terms,
    procedures and limitations relating to the exchange and exercise
    of the warrants.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Transfer
    Agent and Registrar</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The transfer agent and registrar for any warrants will be set
    forth in the applicable prospectus supplement.
</DIV>
<A name='110'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">DESCRIPTION
    OF DEBT SECURITIES</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will issue the debt securities offered by this prospectus and
    any accompanying prospectus supplement under an indenture to be
    entered into between us and the trustee identified in the
    applicable prospectus supplement. The terms of the debt
    securities will include those stated in the indenture and those
    made part of the indenture by reference to the
    Trust&#160;Indenture Act of 1939, as in effect on the date of
    the indenture. We have filed a copy of the form of indenture as
    an exhibit to the registration statement in which this
    prospectus is included. The indenture will be subject to and
    governed by the terms of the Trust&#160;Indenture Act of 1939.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may offer under this prospectus up to an aggregate principal
    amount of $30,000,000 in debt securities, or if debt securities
    are issued at a discount, or in a foreign currency, foreign
    currency units or composite currency, the principal amount as
    may be sold for an initial public offering price of up to
    $30,000,000. Unless otherwise specified in the applicable
    prospectus supplement, the debt securities will represent
    direct, unsecured obligations of the Company and will rank
    equally with all of our other unsecured indebtedness.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The following statements relating to the debt securities and the
    indenture are summaries, qualified in their entirety by
    reference to the detailed provisions of the indenture.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">General</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may issue the debt securities in one or more series with the
    same or various maturities, at par, at a premium, or at a
    discount. We will describe the particular terms of each series
    of debt securities in a prospectus supplement relating to that
    series, which we will file with the SEC.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The prospectus supplement will set forth, to the extent
    required, the following terms of the debt securities in respect
    of which the prospectus supplement is delivered:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the title of the series;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the aggregate principal amount;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the issue price or prices, expressed as a percentage of the
    aggregate principal amount of the debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any limit on the aggregate principal amount;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the date or dates on which principal is payable;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the interest rate or rates (which may be fixed or variable) or,
    if applicable, the method used to determine such rate or rates;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the date or dates from which interest, if any, will be payable
    and any regular record date for the interest payable;
</TD>
</TR>

</TABLE>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    10
</DIV><!-- END PAGE WIDTH -->
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the place or places where principal and, if applicable, premium
    and interest, is payable;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the terms and conditions upon which we may, or the holders may
    require us to, redeem or repurchase the debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the denominations in which such debt securities may be issuable,
    if other than denominations of $1,000 or any integral multiple
    of that number;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    whether the debt securities are to be issuable in the form of
    certificated securities (as described below) or global
    securities (as described below);
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the portion of principal amount that will be payable upon
    declaration of acceleration of the maturity date if other than
    the principal amount of the debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the currency of denomination;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the designation of the currency, currencies or currency units in
    which payment of principal and, if applicable, premium and
    interest, will be made;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    if payments of principal and, if applicable, premium or
    interest, on the debt securities are to be made in one or more
    currencies or currency units other than the currency of
    denomination, the manner in which the exchange rate with respect
    to such payments will be determined;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    if amounts of principal and, if applicable, premium and interest
    may be determined by reference to an index based on a currency
    or currencies or by reference to a commodity, commodity index,
    stock exchange index or financial index, then the manner in
    which such amounts will be determined;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the provisions, if any, relating to any collateral provided for
    such debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any addition to or change in the covenants
    <FONT style="white-space: nowrap">and/or</FONT> the
    acceleration provisions described in this prospectus or in the
    indenture;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any events of default, if not otherwise described below under
    &#147;Events of Default&#148;;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the terms and conditions, if any, for conversion into or
    exchange for shares of our common stock or preferred stock;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    any depositaries, interest rate calculation agents, exchange
    rate calculation agents or other agents;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the terms and conditions, if any, upon which the debt securities
    shall be subordinated in right of payment to other indebtedness
    of the Company.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may issue discount debt securities that provide for an amount
    less than the stated principal amount to be due and payable upon
    acceleration of the maturity of such debt securities in
    accordance with the terms of the indenture. We may also issue
    debt securities in bearer form, with or without coupons. If we
    issue discount debt securities or debt securities in bearer
    form, we will describe material U.S.&#160;federal income tax
    considerations and other material special considerations which
    apply to these debt securities in the applicable prospectus
    supplement.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may issue debt securities denominated in or payable in a
    foreign currency or currencies or a foreign currency unit or
    units. If we do, we will describe the restrictions, elections,
    and general tax considerations relating to the debt securities
    and the foreign currency or currencies or foreign currency unit
    or units in the applicable prospectus supplement.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Exchange
    and/or Conversion Rights</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may issue debt securities which can be exchanged for or
    converted into shares of our common stock or preferred stock. If
    we do, we will describe the terms of exchange or conversion in
    the prospectus supplement relating to these debt securities.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    11
</DIV><!-- END PAGE WIDTH -->
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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Transfer
    and Exchange</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We may issue debt securities that will be represented by either:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    <I>&#147;book-entry securities,&#148;</I> which means that there
    will be one or more global securities registered in the name of
    a depositary or a nominee of a depositary;&#160;or
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    <I>&#147;certificated securities,&#148;</I> which means that
    they will be represented by a certificate issued in definitive
    registered form.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will specify in the prospectus supplement applicable to a
    particular offering whether the debt securities offered will be
    book-entry or certificated securities.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Certificated
    Debt Securities</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If you hold certificated debt securities, you may transfer or
    exchange such debt securities at the trustee&#146;s office or at
    the paying agent&#146;s office or agency in accordance with the
    terms of the indenture. You will not be charged a service charge
    for any transfer or exchange of certificated debt securities but
    may be required to pay an amount sufficient to cover any tax or
    other governmental charge payable in connection with such
    transfer or exchange.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    You may effect the transfer of certificated debt securities and
    of the right to receive the principal of, premium,
    <FONT style="white-space: nowrap">and/or</FONT>
    interest, if any, on the certificated debt securities only by
    surrendering the certificate representing the certificated debt
    securities and having us or the trustee issue a new certificate
    to the new holder.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Global
    Securities</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If we decide to issue debt securities in the form of one or more
    global securities, then we will register the global securities
    in the name of the depositary for the global securities or the
    nominee of the depositary, and the global securities will be
    delivered by the trustee to the depositary for credit to the
    accounts of the holders of beneficial interests in the debt
    securities.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The prospectus supplement will describe the specific terms of
    the depositary arrangement for debt securities of a series that
    are issued in global form. None of our Company, the trustee, any
    payment agent or the security registrar will have any
    responsibility or liability for any aspect of the records
    relating to or payments made on account of beneficial ownership
    interests in a global debt security or for maintaining,
    supervising or reviewing any records relating to these
    beneficial ownership interests.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">No
    Protection in the Event of Change of Control</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The indenture does not have any covenants or other provisions
    providing for a put or increased interest or otherwise that
    would afford holders of our debt securities additional
    protection in the event of a recapitalization transaction, a
    change of control of the Company, or a highly leveraged
    transaction. If we offer any covenants or provisions of this
    type with respect to any debt securities covered by this
    prospectus, we will describe them in the applicable prospectus
    supplement.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Covenants</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Unless otherwise indicated in this prospectus or the applicable
    prospectus supplement, our debt securities will not have the
    benefit of any covenants that limit or restrict our business or
    operations, the pledging of our assets or the incurrence by us
    of indebtedness. We will describe in the applicable prospectus
    supplement any material covenants in respect of a series of debt
    securities.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    12
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<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Consolidation,
    Merger and Sale of Assets</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have agreed in the indenture that we will not consolidate
    with or merge into any other person or convey, transfer, sell or
    lease our properties and assets substantially as an entirety to
    any person, unless:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the person formed by the consolidation or into or with which we
    are merged or the person to which our properties and assets are
    conveyed, transferred, sold or leased, is a corporation
    organized and existing under the laws of the U.S., any state or
    the District of Columbia or a corporation or comparable legal
    entity organized under the laws of a foreign jurisdiction and,
    if we are not the surviving person, the surviving person has
    expressly assumed all of our obligations, including the payment
    of the principal of and, premium, if any, and interest on the
    debt securities and the performance of the other covenants under
    the indenture;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    immediately before and immediately after giving effect to the
    transaction, no event of default, and no event which, after
    notice or lapse of time or both, would become an event of
    default, has occurred and is continuing under the indenture.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Events of
    Default</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Unless otherwise specified in the applicable prospectus
    supplement, the following events will be events of default under
    the indenture with respect to debt securities of any series:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    we fail to pay any principal or premium, if any, when it becomes
    due;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    we fail to pay any interest within 30&#160;days after it becomes
    due;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    we fail to observe or perform any other covenant in the debt
    securities or the indenture for 60&#160;days after written
    notice specifying the failure from the trustee or the holders of
    not less than 25% in aggregate principal amount of the
    outstanding debt securities of that series;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    certain events involving bankruptcy, insolvency or
    reorganization of RXi or any of our significant subsidiaries.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The trustee may withhold notice to the holders of the debt
    securities of any series of any default, except in payment of
    principal of or premium, if any, or interest on the debt
    securities of a series, if the trustee considers it to be in the
    best interest of the holders of the debt securities of that
    series to do so.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If an event of default (other than an event of default resulting
    from certain events of bankruptcy, insolvency or reorganization)
    occurs, and is continuing, then the trustee or the holders of
    not less than 25% in aggregate principal amount of the
    outstanding debt securities of any series may accelerate the
    maturity of the debt securities. If this happens, the entire
    principal amount, plus the premium, if any, of all the
    outstanding debt securities of the affected series plus accrued
    interest to the date of acceleration will be immediately due and
    payable. At any time after the acceleration, but before a
    judgment or decree based on such acceleration is obtained by the
    trustee, the holders of a majority in aggregate principal amount
    of outstanding debt securities of such series may rescind and
    annul such acceleration if:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    all events of default (other than nonpayment of accelerated
    principal, premium or interest) have been cured or waived;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    all lawful interest on overdue interest and overdue principal
    has been paid;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the rescission would not conflict with any judgment or decree.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In addition, if the acceleration occurs at any time when we have
    outstanding indebtedness which is senior to the debt securities,
    the payment of the principal amount of outstanding debt
    securities may be subordinated in right of payment to the prior
    payment of any amounts due under the senior indebtedness, in
    which case the holders of debt securities will be entitled to
    payment under the terms prescribed in the instruments evidencing
    the senior indebtedness and the indenture.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    13
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<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If an event of default resulting from certain events of
    bankruptcy, insolvency or reorganization occurs, the principal,
    premium and interest amount with respect to all of the debt
    securities of any series will be due and payable immediately
    without any declaration or other act on the part of the trustee
    or the holders of the debt securities of that series.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The holders of a majority in principal amount of the outstanding
    debt securities of a series will have the right to waive any
    existing default or compliance with any provision of the
    indenture or the debt securities of that series and to direct
    the time, method and place of conducting any proceeding for any
    remedy available to the trustee, subject to certain limitations
    specified in the indenture.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    No holder of any debt security of a series will have any right
    to institute any proceeding with respect to the indenture or for
    any remedy under the indenture, unless:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the holder gives to the trustee written notice of a continuing
    event of default;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the holders of at least 25% in aggregate principal amount of the
    outstanding debt securities of the affected series make a
    written request and offer reasonable indemnity to the trustee to
    institute a proceeding as trustee;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the trustee fails to institute a proceeding within 60&#160;days
    after such request;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    the holders of a majority in aggregate principal amount of the
    outstanding debt securities of the affected series do not give
    the trustee a direction inconsistent with such request during
    such <FONT style="white-space: nowrap">60-day</FONT>
    period.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    These limitations do not, however, apply to a suit instituted
    for payment on debt securities of any series on or after the due
    dates expressed in the debt securities.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will periodically deliver certificates to the trustee
    regarding our compliance with our obligations under the
    indenture.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Modification
    and Waiver</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    From time to time, we and the trustee may, without the consent
    of holders of the debt securities of one or more series, amend
    the indenture or the debt securities of one or more series, or
    supplement the indenture, for certain specified purposes,
    including:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to provide that the surviving entity following a change of
    control of RXi permitted under the indenture will assume all of
    our obligations under the indenture and debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to provide for certificated debt securities in addition to
    uncertificated debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to comply with any requirements of the SEC under the
    Trust&#160;Indenture Act of 1939;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to provide for the issuance of and establish the form and terms
    and conditions of debt securities of any series as permitted by
    the indenture;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to cure any ambiguity, defect or inconsistency, or make any
    other change that does not materially and adversely affect the
    rights of any holder;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to appoint a successor trustee under the indenture with respect
    to one or more series.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    From time to time we and the trustee may, with the consent of
    holders of at least a majority in principal amount of an
    outstanding series of debt securities, amend or supplement the
    indenture or the debt securities series, or waive compliance in
    a particular instance by us with any provision of the indenture
    or the debt securities. We may not, however, without the consent
    of each holder affected by such action, modify or supplement the
    indenture or the debt securities or waive compliance with any
    provision of the indenture or the debt securities in order to:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    reduce the amount of debt securities whose holders must consent
    to an amendment, supplement, or waiver to the indenture or such
    debt security;
</TD>
</TR>

</TABLE>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    14
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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    reduce the rate of or change the time for payment of interest or
    reduce the amount of or postpone the date for payment of sinking
    fund or analogous obligations;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    reduce the principal of or change the stated maturity of the
    debt securities;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    make any debt security payable in money other than that stated
    in the debt security;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    change the amount or time of any payment required or reduce the
    premium payable upon any redemption, or change the time before
    which no such redemption may be made;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    waive a default in the payment of the principal of, premium, if
    any, or interest on the debt securities or a redemption payment;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    waive a redemption payment with respect to any debt securities
    or change any provision with respect to redemption of debt
    securities;&#160;or
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    take any other action otherwise prohibited by the indenture to
    be taken without the consent of each holder affected by the
    action.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Defeasance
    of Debt Securities and Certain Covenants in Certain
    Circumstances</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The indenture permits us, at any time, to elect to discharge our
    obligations with respect to one or more series of debt
    securities by following certain procedures described in the
    indenture. These procedures will allow us either:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to defease and be discharged from any and all of our obligations
    with respect to any debt securities except for the following
    obligations (which discharge is referred to as &#147;legal
    defeasance&#148;):
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 6%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    (1)&#160;to register the transfer or exchange of such debt
    securities;
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 6%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    (2)&#160;to replace temporary or mutilated, destroyed, lost or
    stolen debt securities;
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 6%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    (3)&#160;to compensate and indemnify the trustee;&#160;or
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 6%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    (4)&#160;to maintain an office or agency in respect of the debt
    securities and to hold monies for payment in trust;&#160;or
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    to be released from our obligations with respect to the debt
    securities under certain covenants contained in the indenture,
    as well as any additional covenants which may be contained in
    the applicable supplemental indenture (which release is referred
    to as &#147;covenant defeasance&#148;).
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In order to exercise either defeasance option, we must deposit
    with the trustee or other qualifying trustee, in trust for that
    purpose:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    money;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    U.S.&#160;Government Obligations (as described below) or Foreign
    Government Obligations (as described below) which through the
    scheduled payment of principal and interest in accordance with
    their terms will provide money;&#160;or
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    a combination of money
    <FONT style="white-space: nowrap">and/or</FONT>
    U.S.&#160;Government Obligations
    <FONT style="white-space: nowrap">and/or</FONT>
    Foreign Government Obligations sufficient in the written opinion
    of a nationally-recognized firm of independent accountants to
    provide money;
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    which in each case specified above, provides a sufficient amount
    to pay the principal of, premium, if any, and interest, if any,
    on the debt securities of the series, on the scheduled due dates
    or on a selected date of redemption in accordance with the terms
    of the indenture.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    In addition, defeasance may be effected only if, among other
    things:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    in the case of either legal or covenant defeasance, we deliver
    to the trustee an opinion of counsel, as specified in the
    indenture, stating that as a result of the defeasance neither
    the trust nor the trustee will be required to register as an
    investment company under the Investment Company Act of 1940;
</TD>
</TR>

</TABLE>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    15
</DIV><!-- END PAGE WIDTH -->
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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    in the case of legal defeasance, we deliver to the trustee an
    opinion of counsel stating that we have received from, or there
    has been published by, the Internal Revenue Service a ruling to
    the effect that, or there has been a change in any applicable
    federal income tax law with the effect that (and the opinion
    shall confirm that), the holders of outstanding debt securities
    will not recognize income, gain or loss for U.S.&#160;federal
    income tax purposes solely as a result of such legal defeasance
    and will be subject to U.S.&#160;federal income tax on the same
    amounts, in the same manner, including as a result of
    prepayment, and at the same times as would have been the case if
    legal defeasance had not occurred;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    in the case of covenant defeasance, we deliver to the trustee an
    opinion of counsel to the effect that the holders of the
    outstanding debt securities will not recognize income, gain or
    loss for U.S.&#160;federal income tax purposes as a result of
    covenant defeasance and will be subject to U.S.&#160;federal
    income tax on the same amounts, in the same manner and at the
    same times as would have been the case if covenant defeasance
    had not occurred;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    certain other conditions described in the indenture are
    satisfied.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    If we fail to comply with our remaining obligations under the
    indenture and applicable supplemental indenture after a covenant
    defeasance of the indenture and applicable supplemental
    indenture, and the debt securities are declared due and payable
    because of the occurrence of any undefeased event of default,
    the amount of money
    <FONT style="white-space: nowrap">and/or</FONT>
    U.S.&#160;Government Obligations
    <FONT style="white-space: nowrap">and/or</FONT>
    Foreign Government Obligations on deposit with the trustee could
    be insufficient to pay amounts due under the debt securities of
    the affected series at the time of acceleration. We will,
    however, remain liable in respect of these payments.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The term &#147;U.S.&#160;Government Obligations&#148; as used in
    the above discussion means securities which are direct
    obligations of or non-callable obligations guaranteed by the
    United States of America for the payment of which obligation or
    guarantee the full faith and credit of the United States of
    America is pledged.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The term &#147;Foreign Government Obligations&#148; as used in
    the above discussion means, with respect to debt securities of
    any series that are denominated in a currency other than
    U.S.&#160;dollars (1)&#160;direct obligations of the government
    that issued or caused to be issued such currency for the payment
    of which obligations its full faith and credit is pledged or
    (2)&#160;obligations of a person controlled or supervised by or
    acting as an agent or instrumentality of such government the
    timely payment of which is unconditionally guaranteed as a full
    faith and credit obligation by that government, which in either
    case under clauses&#160;(1) or (2), are not callable or
    redeemable at the option of the issuer.
</DIV>

<DIV style="margin-top: 12pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">Regarding
    the Trustee</FONT></B>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We will identify the trustee with respect to any series of debt
    securities in the prospectus supplement relating to the
    applicable debt securities. You should note that if the trustee
    becomes a creditor of RXi, the indenture and the
    Trust&#160;Indenture Act of 1939 limit the rights of the trustee
    to obtain payment of claims in certain cases, or to realize on
    certain property received in respect of any such claim, as
    security or otherwise. The trustee and its affiliates may engage
    in, and will be permitted to continue to engage in, other
    transactions with us and our affiliates. If, however, the
    trustee acquires any &#147;conflicting interest&#148; within the
    meaning of the Trust&#160;Indenture Act of 1939, it must
    eliminate such conflict or resign.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The holders of a majority in principal amount of the then
    outstanding debt securities of any series may direct the time,
    method and place of conducting any proceeding for exercising any
    remedy available to the trustee. If an event of default occurs
    and is continuing, the trustee, in the exercise of its rights
    and powers, must use the degree of care and skill of a prudent
    person in the conduct of his or her own affairs. Subject to that
    provision, the trustee will be under no obligation to exercise
    any of its rights or powers under the indenture at the request
    of any of the holders of the debt securities, unless they have
    offered to the trustee reasonable indemnity or security.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    16
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<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#tocpage">Table of Contents</A></H5><P>

<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<A name='111'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">WHERE YOU
    CAN FIND MORE INFORMATION</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We have filed a registration statement on
    <FONT style="white-space: nowrap">Form&#160;S-3</FONT>
    with the SEC for the securities we are offering by this
    prospectus. This prospectus does not include all of the
    information contained in the registration statement. You should
    refer to the registration statement and its exhibits for
    additional information.
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    We are required to file annual and quarterly reports, special
    reports, proxy statements, and other information with the SEC.
    We make these documents publicly available, free of charge, on
    our website at www.rxipharma.com as soon as reasonably
    practicable after filing such documents with the SEC. You can
    read our SEC filings, including the registration statement, on
    the SEC&#146;s website at
    <FONT style="white-space: nowrap">http://www.sec.gov.</FONT>
    You also may read and copy any document we file with the SEC at
    its public reference facility at:
</DIV>

<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <FONT style="font-family: 'Times New Roman', Times">Public
    Reference Room<BR>
    100&#160;F&#160;Street N.E.<BR>
    Washington, DC 20549.
    </FONT>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Please call the SEC at
    <FONT style="white-space: nowrap">1-800-732-0330</FONT>
    for further information on the operation of the public reference
    facilities.
</DIV>
<A name='112'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">INCORPORATION
    OF CERTAIN DOCUMENTS BY REFERENCE</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The SEC allows us to &#147;incorporate by reference&#148; into
    this prospectus the information we file with it, which means
    that we can disclose important information to you by referring
    you to those documents. The information incorporated by
    reference is considered to be part of this prospectus, and
    information in documents that we file later with the SEC will
    automatically update and supersede information in this
    prospectus. We incorporate by reference into this prospectus the
    documents listed below and any future filings made by us with
    the SEC under Section&#160;13(a), 13(c), 14 or 15(d) of the
    Exchange Act until we close this offering, including all filings
    made after the date of the initial registration statement and
    prior to the effectiveness of the registration statement. We
    hereby incorporate by reference the following documents:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0">

<TR>
    <TD width="4%"></TD>
    <TD width="2%"></TD>
    <TD width="94%"></TD>
</TR>

<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    Our Annual Report on
    <FONT style="white-space: nowrap">Form&#160;10-K</FONT>
    for the year ended December&#160;31, 2008;
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    Our Current Reports on
    <FONT style="white-space: nowrap">Form&#160;8-K</FONT>
    filed on March&#160;20, 2009 and April&#160;28, 2009 (excluding
    any information furnished in such reports under Item&#160;2.02,
    Item&#160;7.01 or Item&#160;9.01);
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    The description of our common stock contained in our
    registration statement on
    <FONT style="white-space: nowrap">Form&#160;8-A</FONT>
    filed February&#160;8, 2008, under the Securities Act, including
    any amendment or report filed for the purpose of updating such
    description;&#160;and
</TD>
</TR>


<TR style="line-height: 6pt; font-size: 1pt"><TD>&nbsp;</TD></TR>


<TR valign="top" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <TD>&nbsp;</TD>
    <TD>    &#149;&#160;
</TD>
    <TD align="left">
    Our definitive Proxy Statement on Schedule&#160;14A filed on
    April&#160;23, 2009.
</TD>
</TR>

</TABLE>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    You may request a copy of these filings, at no cost, by writing
    or telephoning us at the following address:
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    RXi Pharmaceuticals Corporation
</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    60 Prescott Street
</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Worcester, MA 01650
</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Attention: Investor Relations
</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Phone:
    <FONT style="white-space: nowrap">(508)&#160;767-3861</FONT>
</DIV>

<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    Copies of these filings are also available, without charge,
    through the &#147;Investor Relations&#148; section of our
    website (www.rxipharma.com) as soon as reasonably practicable
    after they are filed electronically with the SEC. The
    information contained on our website is not a part of this
    prospectus.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    17
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<DIV style="width: 87%; margin-left: 6%"><!-- BEGIN PAGE WIDTH -->
<A name='113'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">LEGAL
    MATTERS</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The validity of the issuance of the securities offered hereby
    will be passed upon for us by Ropes&#160;&#038; Gray LLP,
    Boston, Massachusetts. The validity of any securities will be
    passed upon for any underwriters or agents by counsel that we
    will name in the applicable prospectus supplement.
</DIV>
<A name='114'>
<DIV style="margin-top: 18pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="center" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: #FFFFFF">

    <B><FONT style="font-family: 'Times New Roman', Times">EXPERTS</FONT></B>
</DIV>
</A>
<DIV style="margin-top: 6pt; font-size: 1pt">&nbsp;</DIV>

<DIV align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 4%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    The financial statements as of December&#160;31, 2008 and 2007
    and for the years then ended and for the period from inception
    (January&#160;1, 2003)&#160;through December&#160;31, 2008
    incorporated by reference in this Prospectus have been so
    incorporated in reliance on the report of BDO Seidman, LLP, an
    independent registered public accounting firm, incorporated
    herein by reference, given on the authority of said firm as
    experts in auditing and accounting.
</DIV>

<P align="center" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: #FFFFFF">
    <BR>
    18
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