<SEC-DOCUMENT>0001193125-12-025129.txt : 20120126
<SEC-HEADER>0001193125-12-025129.hdr.sgml : 20120126
<ACCEPTANCE-DATETIME>20120126161502
ACCESSION NUMBER:		0001193125-12-025129
CONFORMED SUBMISSION TYPE:	S-3/A
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20120126
DATE AS OF CHANGE:		20120126

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARROWHEAD RESEARCH CORP
		CENTRAL INDEX KEY:			0000879407
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH [8731]
		IRS NUMBER:				460408024
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	FILING VALUES:
		FORM TYPE:		S-3/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-178532
		FILM NUMBER:		12547852

	BUSINESS ADDRESS:	
		STREET 1:		201 SOUTH LAKE AVENUE
		STREET 2:		SUITE 703
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91101
		BUSINESS PHONE:		626-304-3400

	MAIL ADDRESS:	
		STREET 1:		201 SOUTH LAKE AVENUE
		STREET 2:		SUITE 703
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91101

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INTERACTIVE GROUP INC
		DATE OF NAME CHANGE:	20020509

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INTERACTIVE INC
		DATE OF NAME CHANGE:	19940224
</SEC-HEADER>
<DOCUMENT>
<TYPE>S-3/A
<SEQUENCE>1
<FILENAME>d271952ds3a.htm
<DESCRIPTION>AMENDMENT NO. 1 TO FORM S-3
<TEXT>
<HTML><HEAD>
<TITLE>Amendment No. 1 to Form S-3</TITLE>
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<h5 align="left"><a href="#toc">Table of Contents</a></h5>

  <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>As filed with the Securities and Exchange Commission on January 26, 2012
</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Registration Statement No.&nbsp;333-<U>178532</U> </B></FONT></P>
<P STYLE="font-size:4px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P>
<P STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>UNITED STATES </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="3"><B>Washington, D.C. 20549 </B></FONT></P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>Amendment No. 1 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="5"><B>to </B></FONT></P>  <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>FORM S-3 </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>REGISTRATION STATEMENT </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="3"><B><I>UNDER </I></B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="3"><B><I>THE SECURITIES ACT OF 1933 </I></B></FONT></P><center>
<P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="6"><B>ARROWHEAD
RESEARCH CORPORATION </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>(Exact name of Registrant as Specified in Its Charter) </B></FONT></P>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Delaware</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>46-0408024</B></FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(State of Incorporation)</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(I.R.S. Employer</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="1"><B>Identification Number)</B></FONT></P></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>225 South Lake Avenue, Suite 300 </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Pasadena, CA 91101 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>626-304-3400 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(Address, including zip code and telephone number,
including area code, of Registrant&#146;s principal executive offices) </B></FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center>
<P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Christopher
Anzalone, Chief Executive Officer </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Arrowhead Research Corporation </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>225 South Lake Avenue, Suite 300 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>Pasadena, CA 91101 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>626-304-3400 </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(Name, address, including zip code and telephone number, including area code, of agent for service) </B></FONT></P>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><I>Copies to: </I></B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>Ryan Murr </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Ropes&nbsp;&amp; Gray LLP </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Three Embarcadero Center </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>San Francisco, CA 94111 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>(415) 315-6300 </B></FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Approximate Date of Commencement of Proposed Sale to the Public:</B> From time to time after this Registration Statement becomes effective, as
determined by the Selling Stockholders. </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">If the only securities being registered on this Form are being offered pursuant to
dividend or interest reinvestment plans, please check the following box.&nbsp;&nbsp;&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in
connection with dividend or interest reinvestment plans, check the following box.&nbsp;&nbsp;&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#120;</FONT> </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">If this Form is used to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act Registration Statement
number of the earlier effective registration statement for the same offering.&nbsp;&nbsp;&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act Registration Statement number of the earlier
effective registration statement for the same offering.&nbsp;&nbsp;&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become
effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.&nbsp;&nbsp;&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register
additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.&nbsp;&nbsp;&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller
reporting company. See the definitions of &#147;large accelerated filer,&#148; &#147;accelerated filer&#148; and &#147;smaller reporting company&#148; in Rule&nbsp;12b-2 of the Exchange Act. </FONT></P>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Large&nbsp;accelerated&nbsp;filer</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Accelerated&nbsp;filer</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT></FONT></TD></TR>
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<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Non-accelerated filer</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT>&nbsp;&nbsp;(Do not check if a smaller reporting company)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Smaller&nbsp;reporting&nbsp;company</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#120;</FONT></FONT></TD></TR>
</TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>   <center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>The registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until
the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section&nbsp;8(a) of the Securities Act of 1933, as amended, or until the Registration
Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section&nbsp;8(a), may determine. </B></FONT></P> <P STYLE="font-size:8px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P>
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<h5 align="left"><a href="#toc">Table of Contents</a></h5>

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Arial Narrow" SIZE="2" COLOR="#de1a1e"><B>The information in this prospectus is not complete and may be changed. We may not sell these
securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the
offer or sale is not permitted. </B></FONT></P> <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>  <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2" COLOR="#de1a1e"><B>Subject to Completion, dated&nbsp;January 26, 2012 </B></FONT></P>  <P STYLE="margin-top:6px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Prospectus
</B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="6"><B>Arrowhead Research Corporation </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="4"><B>3,000,000 shares of Common Stock </B></FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center>
<P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">This prospectus
relates to the sale of up to 3,000,000 shares of our common stock which may be offered by the selling stockholder, Lincoln Park Capital Fund, LLC, or (&#147;LPC&#148;). The shares of common stock being offered by the selling stockholder are issuable
pursuant to the Purchase Agreement between the Company and LPC dated October&nbsp;20, 2011 (the &#147;Purchase Agreement&#148;). Please refer to the section of this prospectus entitled &#147;The LPC Transaction&#148; for a description of the
Purchase Agreement and the section entitled &#147;Selling Stockholder&#148; for additional information. The prices at which LPC may sell the shares may be determined by the prevailing market price for the shares or in negotiated transactions. We
will not receive proceeds from the sale of our shares by LPC. </FONT></P>  <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The Company&#146;s common stock is traded on the Nasdaq
Capital Market under the symbol &#147;ARWR&#148;. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">On January 24, 2012, the last reported sale price for our common stock as
reported on the NASDAQ Capital Market was $5.27 per share. We have applied to have the shares of common stock offered pursuant to this prospectus approved for listing on the NASDAQ Capital Market. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The selling stockholder is an &#147;underwriter&#148; within the meaning of the Securities Act of 1933, as amended. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Our principal executive offices are located at 225&nbsp;South Lake Avenue, Suite&nbsp;300, Pasadena, California 91101, and our telephone
number is (626)&nbsp;304-3400. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><I>Investing in our securities involves a high degree of risk. You should carefully
consider the <A HREF="#tx271952_5">Risk Factors</A> beginning on page 4 before you invest in our securities. </I></B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or
determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense. </B></FONT></P>  <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">The
date of this prospectus is&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; , 2012 </FONT></P>

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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="toc"></A>Table of Contents </B></FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_1">ABOUT THIS PROSPECTUS</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">2</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
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<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_2">SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">2</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
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<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_3">ABOUT THE COMPANY</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">3</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
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<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_4">THE OFFERING</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">3</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
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<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_5">RISK FACTORS</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">4</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_6">USE OF PROCEEDS</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">5</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_7">THE LPC TRANSACTION</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">5</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_8">SELLING STOCKHOLDER</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">8</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_9">PLAN OF DISTRIBUTION</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">9</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_10">EXPERTS</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">10</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_11">LEGAL MATTERS</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">10</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_12">WHERE YOU CAN FIND MORE INFORMATION</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">10</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><A HREF="#tx271952_13">INCORPORATION OF CERTAIN INFORMATION BY REFERENCE</A></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">10</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
</TABLE>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">1 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
<h5 align="left"><a href="#toc">Table of Contents</a></h5>

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_1"></A>ABOUT THIS PROSPECTUS </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">You should read this prospectus, any applicable prospectus supplement and the information incorporated by reference in this prospectus
before making an investment in the securities of Arrowhead Research Corporation. See &#147;Where You Can Find Additional Information&#148; for more information, page 10. You should rely only on the information contained in or incorporated by
reference in this prospectus or a prospectus supplement. The Company has not authorized anyone to provide you with different information. This document may be used only in jurisdictions where offers and sales of these securities are permitted. You
should assume that information contained in this prospectus, or in any document incorporated by reference, is accurate only as of any date on the front cover of the applicable document. Our business, financial condition, results of operations and
prospects may have changed since that date. </FONT></P> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_2"></A>SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS
</B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">This prospectus contains forward-looking statements within the meaning of the federal securities laws. You can identify
forward-looking statements by the use of the words &#147;believe,&#148; &#147;expect,&#148; &#147;anticipate,&#148; &#147;intend,&#148; &#147;estimate,&#148; &#147;project,&#148; &#147;will,&#148; &#147;should,&#148; &#147;may,&#148;
&#147;plan,&#148; &#147;intend,&#148; &#147;assume&#148; and other expressions which predict or indicate future events and trends and which do not relate to historical matters. You should not rely on forward-looking statements, because they involve
known and unknown risks, uncertainties and other factors, some of which are beyond the control of the Company. These risks, uncertainties and other factors may cause the actual results, performance or achievements of the Company to be materially
different from the anticipated future results, performance or achievements expressed or implied by the forward-looking statements. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Factors that might cause these differences include the following: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the integration of multiple technologies and programs; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the ability to successfully complete development and commercialization of products and the Company&#146;s expectations regarding market growth;
</FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the cost, timing, scope and results of ongoing safety and efficacy trials of preclinical and clinical testing; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the ability to successfully complete product research and further development; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the volume and profitability of product sales of future products; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">changes in existing and potential relationships with corporate collaborators and partners; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the availability, cost, delivery and quality of materials supplied by contract manufacturers; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the timing, cost and uncertainty of obtaining regulatory approvals of our products; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the ability to obtain substantial additional funding; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the ability to develop and commercialize products before competitors that are superior to the alternatives developed by competitors;
</FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the ability to retain certain members of management; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>

<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the Company&#146;s expectations regarding research and development expenses and general and administrative expenses; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the Company&#146;s expectations regarding cash balances, capital requirements, anticipated revenue and expenses, including infrastructure expenses;
</FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">our belief regarding the validity of our patents and potential litigation; and </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">other factors detailed from time to time in filings with the Securities and Exchange Commission. </FONT></P></TD></TR></TABLE>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">2 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
<h5 align="left"><a href="#toc">Table of Contents</a></h5>

 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">In addition, the factors described under the section captioned &#147;Risk Factors&#148; in
this prospectus, as may be updated from time to time by our future filings under the Securities Exchange Act, and elsewhere in the documents incorporated by reference in this prospectus, may result in these differences. You should carefully review
all of these factors. These forward-looking statements were based on information, plans and estimates at the date of this prospectus, and we assume no obligation to update any forward-looking statements to reflect changes in underlying assumptions
or factors, new information, future events or other changes. </FONT></P> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_3"></A>ABOUT THE COMPANY </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2"><I>Unless otherwise noted, (1)&nbsp;the term &#147;Arrowhead Research&#148; refers to Arrowhead Research Corporation, a Delaware
corporation, formerly known as InterActive Group, Inc., (2)&nbsp;the terms &#147;Arrowhead,&#148; the &#147;Company,&#148; &#147;we,&#148; &#147;us,&#148; and &#147;our,&#148; refer to the ongoing business operations of Arrowhead and its
subsidiaries, whether conducted through Arrowhead Research or a subsidiary of the company, and (3)&nbsp;the term &#147;Common Stock&#148; refers to shares of Arrowhead Research&#146;s Common Stock and the term &#147;stockholder(s)&#148; refers to
the holders of Common Stock or securities exercisable for Common Stock. </I></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Arrowhead Research Corporation is a clinical
stage nanomedicine company developing innovative therapies at the interface of biology and nanoengineering. Arrowhead&#146;s world-class capabilities and intellectual property covering nucleic acid delivery, siRNA chemistry, and tissue targeting
allow it to design and develop therapeutic agents for a wide range of diseases. The company&#146;s lead products include CALAA-01, an oncology drug candidate based on the gene silencing RNA interference (RNAi) mechanism, and Adipotide&#153;, an
anti-obesity peptide that targets and kills the blood vessels that feed white adipose tissue. Arrowhead is leveraging its proprietary Dynamic PolyConjugate (DPC)&#153;, Liposomal Nanoparticle (LNP), and RONDEL&#153; delivery platforms to support its
own pipeline of preclinical and clinical candidates and to secure external partnerships and collaborations with biotech and pharmaceutical companies. </FONT></P>  <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Our common stock is listed on the Nasdaq Capital Market under the symbol &#147;ARWR&#148;. </FONT></P>  <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Our executive offices are located at 225 South Lake Avenue, Suite 300, Pasadena CA 91101 and our telephone number is (626)&nbsp;304-3400. Additional information regarding our company, including our
audited financial statements and descriptions of our business, is contained in the documents incorporated by reference into this prospectus. See &#147;Where You Can Find More Information&#148; on page&nbsp;10 and &#147;Incorporation of Certain
Information by Reference&#148; on page&nbsp;10. </FONT></P> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_4"></A>THE OFFERING </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">On October&nbsp;20, 2011, we executed a Purchase Agreement and a Registration Rights Agreement with Lincoln Park Capital Fund, LLC. Under
the Purchase Agreement, we have the right to sell to LPC up to $15,000,000 of our common stock at our discretion as described below. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Pursuant to the Registration Rights Agreement, we are filing this registration statement and prospectus with the Securities and Exchange Commission (the &#147;SEC&#148;) covering shares that have been
issued or may be issued to LPC under the Purchase Agreement. We do not have the right to commence sales of our shares to LPC until four business days following the satisfaction of certain conditions set forth in the Purchase Agreement (the
&#147;Commencement Date&#148;), including that the SEC has declared effective the registration statement of which this Prospectus is a part. During the approximately 36 months after the Commencement Date, we have the right to direct LPC to purchase
up to $15,000,000 of our common stock in amounts up to $500,000 of our common stock as often as every four (4)&nbsp;business days, subject to certain conditions. Under certain circumstances we can increase the amount to be purchased to up to
$1,000,000 of our common stock. No sales of shares may occur at a price below $2.00 per share. There are no trading volume requirements or restrictions under the Purchase Agreement, and we will control the timing and amount of any sales of our
common stock to LPC. The purchase price of the shares will be based on the market prices of our shares immediately preceding the time of sale as computed under the Purchase Agreement without any fixed discount. We may at any time in our sole
discretion terminate the Purchase Agreement without fee, penalty or cost upon one business day notice. As payment to LPC of the $269,500 commitment fee pursuant to the Purchase Agreement, we issued 68,925 shares of our common stock to LPC at $3.91
per share. We may issue up to an additional 88,618 shares pro rata as a further $346,500 commitment fee as LPC purchases up to $15,000,000 of our stock pursuant to the Purchase Agreement. LPC may not assign or transfer its rights and obligations
under the Purchase Agreement. </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">3 </FONT></P>


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  <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">As of January 24, 2011, we had 10,530,524 shares of common stock outstanding (10,443,147
shares held by non-affiliates) including 68,925 shares which we have already issued to LPC and are offered by LPC pursuant to this Prospectus. 3,000,000 shares are offered hereby consisting of 68,925 shares that we issued to LPC as an initial
commitment fee, 88,618 shares that we may issue pro rata as up to $15,000,000 of our common stock is purchased by LPC and the remainder representing shares we may sell to LPC under the Purchase Agreement. If all of the 3,000,000 shares offered by
LPC hereby were issued and outstanding as of the date hereof, such shares would represent 21.7% of the total common stock outstanding or 21.9% of the shares outstanding held by non-affiliates, as of the date hereof. If we elect to issue to LPC more
than the 3,000,000 shares offered under this prospectus, which we have the right but not the obligation to do, we must first register under the Securities Act any such additional shares before selling such additional shares to LPC, which could cause
substantial dilution to our shareholders. Before we begin selling shares to LPC pursuant to the Purchase Agreement, we are required to seek shareholder approval to maintain compliance with the NASDAQ Capital Market rules. The number of shares
ultimately offered for sale by LPC is dependent upon the number of shares purchased by LPC under the Purchase Agreement. </FONT></P>
<P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_5"></A>RISK FACTORS </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">We are a development-stage company and we have limited historical operations. Before making an investment decision, you should carefully consider the risks described herein and in the sections entitled
&#147;Risk Factors&#148; in our most recent Annual Report on Form 10-K or Quarterly Report on form 10-Q, as filed with the SEC, which are incorporated herein by reference in their entirety, as well any amendment or updates to our risk factors
reflected in subsequent filings with the SEC, including the applicable prospectus supplement. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The trading price of our
securities could decline due to any of these risks, and you may lose all or part of your investment. This prospectus and the incorporated documents also contain forward-looking statements that involve risks and uncertainties. Our actual results
could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks mentioned elsewhere in this prospectus. </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B><I>Our facility with Lincoln Park Capital Fund, LLP may not be sufficient to satisfy our capital requirements. </I></B></FONT></P>  <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">We may direct LPC to purchase up to $15,000,000 of our common stock under our agreement over a thirty (36)&nbsp;month period generally in amounts of up to $500,000 of our common stock every four business
days, which amounts may be increased under certain circumstances. However, LPC shall not have the right nor the obligation to purchase any shares of our common stock on any business day that the market price of our common stock is less than $2.00.
Assuming a purchase price of $5.27&nbsp;per share (the closing sale price of our common stock on January 24, 2012) and the purchase by LPC of the full 3,000,000 purchase shares, proceeds to us would be approximately $15 million. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The extent to which we rely on LPC as a source of funding will depend on a number of factors including, the prevailing market price of
our common stock and the extent to which we are able to secure working capital from other sources. Specifically, LPC shall not have the right nor the obligation to purchase any shares of our common stock on any business days that the market price of
our common stock is less than $2.00. If sufficient funding from LPC were to prove unavailable or prohibitively dilutive, we will need to secure another source of funding in order to satisfy our working capital needs. Even if we sell all $15,000,000
under the Purchase Agreement to LPC, we may still need additional capital to fully implement our business, operating and development plans. The inability to raise additional capital necessary to implement our business, operating and development
plans on acceptable terms could cause a material adverse effect on our business, operating results, financial condition and prospects. </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">4 </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><I>The sale of our common stock to LPC may cause dilution and the sale of the shares of common stock
acquired by LPC could cause the price of our common stock to decline. </I></B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">In connection with entering into the Purchase
Agreement, our board of directors authorized the sale to LPC of up to an aggregate of $15,000,000 of our common stock exclusive of the 68,925 commitment shares issued and the 88,618 commitment shares that may be issued. The number of shares
ultimately offered for sale by LPC under this prospectus is dependent upon the number of shares purchased by LPC under the Purchase Agreement. The purchase price for the common stock sold to LPC pursuant to the Purchase Agreement will fluctuate
based on the trading price of our common stock. All 3,000,000 shares registered in this offering are expected to be freely tradable. It is anticipated that shares registered in this offering will be sold over a period of up to 36 months from the
date of this prospectus. Depending upon market liquidity at the time, a sale of shares pursuant to this offering could cause the trading price of our common stock to decline. We can elect to direct purchases in our sole discretion but no sales may
occur if the trading price of our common stock is below $2.00 and therefore, LPC may ultimately purchase all, some or none of the 3,000,000 shares of common stock not yet issued but registered in this offering. After LPC has acquired such shares, it
may sell all, some or none of such shares. Therefore, sales to LPC by us under the Purchase Agreement may result in substantial dilution to the interests of other holders of our common stock. The sale of a substantial number of shares of our common
stock pursuant to this offering, or anticipation of such sales, could make it more difficult for us to sell equity or equity-related securities in the future at a time and at a price favorable to us. However, we have the right to control the timing
and amount of any sales of our shares to LPC and the Purchase Agreement may be terminated by us at any time at our discretion without any cost to us. </FONT></P> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_6"></A>USE OF PROCEEDS </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">This prospectus relates to
shares of our common stock that may be offered and sold from time to time by the selling stockholder. We will receive no proceeds from the sale of shares of common stock in this offering. However, we may receive proceeds of up to $15,000,000 under
the Purchase Agreement. We will have broad discretion over the use of any proceeds we receive from LPC under the Purchase Agreement. We intend to use any such proceeds for general corporate purposes, which may include one or more of the following:
</FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="1%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">working capital; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="1%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">research and clinical development activities; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="1%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">potential future acquisitions of companies and/or technologies; and </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="1%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">capital expenditures. </FONT></P></TD></TR></TABLE> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_7"></A>THE LPC TRANSACTION </B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><U>General </U></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">On October&nbsp;20, 2011, we executed a Purchase Agreement and a Registration Rights Agreement with Lincoln Park Capital Fund, LLC. Under
the Purchase Agreement, we have the right to sell to LPC up to $15,000,000 of our common stock at our discretion as described below. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Pursuant to the Registration Rights Agreement, we are filing this registration statement and prospectus with the Securities and Exchange Commission (the &#147;SEC&#148;) covering shares that have been
issued or may be issued to LPC under the Purchase Agreement. We do not have the right to commence sales of our shares to LPC until four business days following the satisfaction of certain conditions set forth in the Purchase Agreement (the
&#147;Commencement Date&#148;), including that the SEC has declared effective the registration statement of which this Prospectus is a part. During the approximately 36 months after the Commencement Date, we have the right to direct LPC to purchase
up to $15,000,000 of our common stock in amounts up to $500,000 of our common stock as often as every four (4)&nbsp;business days, subject to certain conditions. Under certain circumstances we can increase the amount to be purchased to up to
$1,000,000 of our common stock. No sales of shares may occur at a price below $2.00 per share. There are no trading volume requirements or restrictions under the Purchase Agreement, and we will control the timing and amount of any sales of our
common stock to LPC. The purchase price of the shares will be based on the market prices of our shares immediately preceding the time of sale as computed under the Purchase Agreement without any fixed discount. We may at any time in our sole
discretion terminate the Purchase </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">5 </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">
Agreement without fee, penalty or cost upon one business day notice. As payment to LPC of the $269,500 commitment fee pursuant to the Purchase Agreement, we issued 68,925 shares of our common
stock to LPC at $3.91 per share. We may issue up to an additional 88,618 shares pro rata as a further $346,500 commitment fee as LPC purchases up to $15,000,000 of our stock pursuant to the Purchase Agreement. LPC may not assign or transfer its
rights and obligations under the Purchase Agreement. </FONT></P>  <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">As of January&nbsp;24, 2012, we had 10,530,524 shares of common
stock outstanding (10,443,147 shares held by non-affiliates) including 68,925 shares which we have already issued to LPC and are offered by LPC pursuant to this Prospectus. 3,000,000 shares are offered hereby consisting of 68,925 shares that we
issued to LPC as an initial commitment fee, 88,618 shares that we may issue pro rata as up to $15,000,000 of our common stock is purchased by LPC and the remainder representing shares we may sell to LPC under the Purchase Agreement. If all of the
3,000,000 shares offered by LPC hereby were issued and outstanding as of the date hereof, such shares would represent 21.7% of the total common stock outstanding or 21.9% of the shares outstanding held by non-affiliates, as of the date hereof. If we
elect to issue to LPC more than the 3,000,000 shares offered under this prospectus, which we have the right but not the obligation to do, we must first register under the Securities Act any such additional shares before selling such additional
shares to LPC, which could cause substantial dilution to our shareholders. Before we begin selling shares to LPC pursuant to the Purchase Agreement, we are required to seek shareholder approval to maintain compliance with the NASDAQ Capital Market
rules. The number of shares ultimately offered for sale by LPC is dependent upon the number of shares purchased by LPC under the Purchase Agreement. </FONT></P>  <P STYLE="margin-top:18px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><U>Purchase Of Shares Under The Purchase Agreement </U></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Under the Purchase
Agreement, on any business day selected by us and as often as every four (4)&nbsp;business days, we may direct LPC to purchase up to $500,000 of our common stock. The purchase price per share is equal to the lesser of: </FONT></P>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the lowest sale price of our common stock on the purchase date; or </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the average of the three (3)&nbsp;lowest closing sale prices of our common stock during the twelve (12)&nbsp;consecutive business days prior to the
purchase. </FONT></P></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The purchase price will be equitably adjusted for any reorganization, recapitalization, non-cash
dividend, stock split, or other similar transaction occurring during the business days used to compute the purchase price. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">In
addition to purchases of up to $500,000 of common stock, we may direct LPC as often as every four (4)&nbsp;business days to purchase up to $600,000 of our common stock provided on the purchase date our share price is not below $9.00 per share. We
may increase this amount up to $800,000 of our common stock provided on the purchase date our share price is not below $12.00 per share. We may increase this amount up to $1,000,000 of our common stock provided on the purchase date our share price
is not below $15.00 per share. </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><U>Minimum Purchase Price </U></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Under the Purchase Agreement, we have set a minimum purchase price (&#147;floor price&#148;) of $2.00. LPC shall not have the right nor the obligation to purchase any shares of our common stock in the
event that the purchase price would be less than the floor price. </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><U>Events of Default</U> </FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The following events constitute events of default under the Purchase Agreement: </FONT></P>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the effectiveness of the registration statement of which this prospectus is a part of lapses for any reason (including, without limitation, the
issuance of a stop order) or is unavailable to LPC for sale of our common stock offered hereby and such lapse or unavailability continues for a period of ten (10)&nbsp;consecutive business days or for more than an aggregate of thirty
(30)&nbsp;business days in any 365-day period; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">suspension by our principal market of our common stock from trading for a period of three (3)&nbsp;consecutive business days;
</FONT></P></TD></TR></TABLE>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">6 </FONT></P>


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<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the de-listing of our common stock from our principal market provided our common stock is not immediately thereafter listed or quoted, as applicable,
on the Nasdaq Capital Market, the OTC Bulletin Board including comparable markets, the Nasdaq Global Select Market, the NYSE AMEX, or the New York Stock Exchange; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the transfer agent&#146;s failure for five (5)&nbsp;business days to issue to LPC shares of our common stock which LPC is entitled to under the
Purchase Agreement; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">any material breach of the representations, warranties or covenants contained in the Purchase Agreement or any related agreements which has or which
could have a material adverse effect on us subject to a cure period of five (5)&nbsp;business days; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">any participation or threatened participation in insolvency or bankruptcy proceedings by or against us; or </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">the Company is unable to effect sales pursuant to the Purchase Agreement without violating the applicable rules of the Nasdaq Stock Market or any other
principal market on which the Company&#146;s common stock is listed or quoted. </FONT></P></TD></TR></TABLE> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><U>Our Termination Rights </U></FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">We have the unconditional right to terminate the Purchase Agreement at any time for any reason or no reason by giving notice to LPC;
provided that after the Commencement Date such termination shall not become effective until one day after it is delivered. There are no termination fees payable by us. </FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><U>No Short-Selling or Hedging by LPC </U></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">LPC has agreed that during the term of
the Purchase Agreement neither it nor any of its affiliates shall engage in any direct or indirect short-selling or hedging transaction of our common stock that establishes a net short position. </FONT></P>
<P STYLE="margin-top:18px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><U>Effect of Performance of the Purchase Agreement on Our Stockholders </U></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">All 3,000,000 shares registered in this offering are expected to be freely tradable. It is anticipated that shares registered in this offering will be sold, if at all, over a period of up to 36 months
from the date of this prospectus. The sale by LPC of a significant amount of shares registered in this offering at any given time could cause the market price of our common stock to decline and to be highly volatile. LPC may ultimately purchase all,
some or none of the 2,931,075 shares of common stock that are registered in this offering but not yet held by LPC. After it has acquired such shares, it may sell all, some or none of such shares. Therefore, sales to LPC by us under the Purchase
Agreement may result in substantial dilution to the interests of other holders of our common stock. However, we have the right to control the timing and amount of any sales of our shares to LPC and the agreement may be terminated by us at any time
at our discretion without any cost to us. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">In connection with entering into the agreement, our board of directors authorized
the sale to LPC of up to an aggregate of $15,000,000 of our common stock exclusive of the 68,925 commitment shares issued and the 88,618 commitment shares that may be issued. We have the right to terminate the agreement without any payment or
liability to LPC at any time, including in the event that all $15,000,000 is sold to LPC under the Purchase Agreement.<B> </B>The number of shares ultimately offered for sale by LPC under this prospectus is dependent upon the number of shares
purchased by LPC under the agreement. The following table sets forth the proceeds we would receive from LPC for the sale of shares pursuant to the Purchase Agreement and the number of shares that would subsequently be available for sale by LPC
pursuant to this offering: </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">7 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
<h5 align="left"><a href="#toc">Table of Contents</a></h5>


<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD WIDTH="47%"></TD>
<TD VALIGN="bottom" WIDTH="12%"></TD>
<TD></TD>
<TD VALIGN="bottom" WIDTH="12%"></TD>
<TD></TD>
<TD VALIGN="bottom" WIDTH="12%"></TD>
<TD></TD></TR>
<TR>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Assumed Average</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="1"><B>Purchase Price</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Number&nbsp;of&nbsp;Shares<BR>Issued to LPC if<BR>Full&nbsp;Purchase&nbsp;(1)&nbsp;(2)</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Percentage&nbsp;of&nbsp;Outstanding<BR>Shares&nbsp;After&nbsp;Giving&nbsp;Effect&nbsp;to<BR>the Issuance to LPC (3)</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Proceeds&nbsp;from&nbsp;the&nbsp;Sale&nbsp;of&nbsp;Shares</B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>to LPC Under the</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="1"><B>LPC Purchase Agreement</B></FONT></P></TD></TR>


<TR BGCOLOR="#cceeff">
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$2.00 (4)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">3,000,000</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">22.2%</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$5,929,106</FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$5.27 (5)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">2,934,918</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">21.8%</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$15,000,000</FONT></TD></TR>
<TR BGCOLOR="#cceeff">
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$7.50</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">2,088,618</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">16.0%</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$15,000,000</FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$10.00</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">1,588,618</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">12.5%</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$15,000,000</FONT></TD></TR>
<TR BGCOLOR="#cceeff">
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$15.00</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">1,088,618</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">8.7%</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">$15,000,000</FONT></TD></TR>
</TABLE>  <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="line-height:8px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000;width:10%">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Although the Purchase Agreement provides that we may sell up to $15,000,000 of our common stock to LPC, we are only registering 3,000,000 shares, which may or may not
cover the shares purchased by LPC and the initial and additional commitment shares, depending on the purchase price per share. As a result, we have only included in this column up to the number of shares that are registered in this offering.
</FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">The number of shares to be issued to LPC and available for sale by LPC pursuant to this offering includes the number of shares to be purchased at the applicable price
plus the additional commitment shares (but not the initial commitment shares). The Company will receive no proceeds from the issuance of the additional commitment shares. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(3)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">The denominator is based on the sum of i) 10,530,524 shares outstanding as of January 24, 2012, which includes the 68,925 initial commitment shares already issued to
LPC, which are part of this offering, plus ii) the number of shares set forth in the second column, which includes the additional commitment shares issued pro rata as up to $15,000,000 of our common stock is purchased by LPC. The numerator is based
on the number of shares issuable under the Purchase Agreement at the corresponding assumed purchase price set forth in the first column. The number of shares in the second column does not include shares that may be issued to LPC that exceed the
3,000,000 shares that are a part of this offering. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(4)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Under the Purchase Agreement, we may not sell and LPC may not purchase any shares in the event the purchase price of such shares is below $2.00.
</FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(5)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">The closing sale price of our shares on January 24, 2012. </FONT></TD></TR></TABLE>  <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_8"></A>SELLING STOCKHOLDER </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The following table presents
information regarding the selling stockholder. Neither the selling stockholder nor any of its affiliates has held a position or office, or had any other material relationship, with us. </FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD WIDTH="37%"></TD>
<TD VALIGN="bottom" WIDTH="9%"></TD>
<TD></TD>
<TD VALIGN="bottom" WIDTH="9%"></TD>
<TD></TD>
<TD VALIGN="bottom" WIDTH="9%"></TD>
<TD></TD>
<TD VALIGN="bottom" WIDTH="9%"></TD>
<TD></TD>
<TD VALIGN="bottom" WIDTH="9%"></TD>
<TD></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP> <P STYLE="border-bottom:1px solid #000000;width:66pt"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Selling Stockholder</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Shares<BR>Beneficially<BR>Owned&nbsp;Before<BR>Offering</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Percentage&nbsp;of<BR>Outstanding&nbsp;Shares<BR>Beneficially Owned<BR>Before Offering</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Shares&nbsp;to&nbsp;be&nbsp;Sold&nbsp;in&nbsp;the<BR>Offering&nbsp;Assuming&nbsp;The<BR>Company Issues The<BR>Maximum
Number of<BR>Shares&nbsp;Under&nbsp;the&nbsp;Purchase<BR>Agreement</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Number of<BR>Shares<BR>Beneficially<BR>Owned&nbsp;After<BR>Offering (3)</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Percentage&nbsp;of<BR>Outstanding&nbsp;Shares<BR>Beneficially Owned<BR>After Offering</B></FONT></TD></TR>


<TR BGCOLOR="#cceeff">
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Lincoln Park Capital Fund, LLC (1)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">168,925(2)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">1.6%(2)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">3,000,000</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">100,000</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></TD></TR>
</TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="line-height:8px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000;width:10%">&nbsp;</P>
<P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">*less than 1% </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Josh Scheinfeld and Jonathan Cope, the principals of LPC, are deemed to be beneficial owners of all of the shares of common stock owned by LPC. Messrs. Scheinfeld and
Cope have shared voting and disposition power over the shares being offered under this Prospectus. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Includes 68,925 shares of our common stock previously issued to LPC under the Purchase Agreement as an initial commitment fee and 100,000 shares LPC acquired in a sale
of stock that is not a part of this offering. We may at our discretion elect to issue to LPC up to an additional 2,931,075 shares of our common stock in this offering under the Purchase Agreement, which are included in this offering. Such shares are
not included in determining the percentage of shares beneficially owned before the offering. </FONT></TD></TR></TABLE>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">8 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
<h5 align="left"><a href="#toc">Table of Contents</a></h5>


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(3)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">We have no assurance that the selling stockholder will sell any of the common stock being registered for sale.&nbsp;For purposes of this table, we have assumed that the
selling stockholder will have sold all of the shares covered by this prospectus upon completion of the offering, including such shares issuable upon the delivery of purchase notices pursuant to the terms of the Purchase Agreement. Additionally, we
have assumed that the selling stockholder does not acquire, pursuant to the Purchase Agreement or otherwise, more than the 3,000,000 shares included in this offering. </FONT></TD></TR></TABLE>
<P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_9"></A>PLAN OF DISTRIBUTION </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">The common stock offered by this prospectus is being offered by Lincoln Park Capital Fund, LLC, the selling stockholder<B>.</B> The common stock may be sold or distributed from time to time by the selling
stockholder directly to one or more purchasers or through brokers, dealers, or underwriters who may act solely as agents at market prices prevailing at the time of sale, at prices related to the prevailing market prices, at negotiated prices, or at
fixed prices, which may be changed. The sale of the common stock offered by this Prospectus may be effected in one or more of the following methods: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">ordinary brokers&#146; transactions; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">transactions involving cross or block trades; </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">through brokers, dealers, or underwriters who may act solely as agents </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#147;at the market&#148; into an existing market for the common stock; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">in other ways not involving market makers or established business markets, including direct sales to purchasers or sales effected through agents;
</FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">in privately negotiated transactions; or </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">any combination of the foregoing. </FONT></P></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">In order to comply with the securities laws of certain states, if applicable, the shares may be sold only through registered or licensed brokers or dealers. In addition, in certain states, the shares may
not be sold unless they have been registered or qualified for sale in the state or an exemption from the registration or qualification requirement is available and complied with. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Brokers, dealers, underwriters, or agents participating in the distribution of the shares as agents may receive compensation in the form
of commissions, discounts, or concessions from the selling stockholder and/or purchasers of the common stock for whom the broker-dealers may act as agent. The compensation paid to a particular broker-dealer may be less than or in excess of customary
commissions. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">LPC is an &#147;underwriter&#148; within the meaning of the Securities Act. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Neither we nor LPC can presently estimate the amount of compensation that any agent will receive. We know of no existing arrangements
between LPC, any other shareholder, broker, dealer, underwriter, or agent relating to the sale or distribution of the shares offered by this Prospectus. At the time a particular offer of shares is made, a prospectus supplement, if required, will be
distributed that will set forth the names of any agents, underwriters, or dealers and any compensation from the selling stockholder, and any other required information. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">We will pay all of the expenses incident to the registration, offering, and sale of the shares to the public other than commissions or discounts of underwriters, broker-dealers, or agents. We have also
agreed to indemnify LPC and related persons against specified liabilities, including liabilities under the Securities Act. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers, and controlling
persons, we have been advised that in the opinion of the SEC this indemnification is against public policy as expressed in the Securities Act and is therefore, unenforceable. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">LPC and its affiliates have agreed not to engage in any direct or indirect short selling or hedging of our common stock during the term of the Purchase Agreement. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">We have advised LPC that while it is engaged in a distribution of the shares included in this Prospectus it is required to comply with
Regulation M promulgated under the Securities Exchange Act of 1934, as amended. With certain exceptions, Regulation M precludes the selling stockholder, any affiliated purchasers, and any broker-dealer
</FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">9 </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">
or other person who participates in the distribution from bidding for or purchasing, or attempting to induce any person to bid for or purchase any security which is the subject of the
distribution until the entire distribution is complete. Regulation M also prohibits any bids or purchases made in order to stabilize the price of a security in connection with the distribution of that security. All of the foregoing may affect the
marketability of the shares offered hereby this Prospectus. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">This offering will terminate on the date that all shares offered
by this Prospectus have been sold by LPC. </FONT></P> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_10"></A>EXPERTS </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The financial statements of the Company incorporated in this prospectus by reference from the Company&#146;s Annual Report on Form 10-K
for the year ended September&nbsp;30, 2011, have been audited by Rose, Snyder&nbsp;&amp; Jacobs, a corporation of Certified Public Accountants, as stated in their report incorporated by reference, and given upon the authority of said firm as experts
in auditing and accounting. </FONT></P>  <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_11"></A>LEGAL MATTERS </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Certain legal matters, including the validity of the securities offered pursuant to this registration statement, will be passed upon for
us by Ropes&nbsp;&amp; Gray LLP, San Francisco, California. </FONT></P> <P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_12"></A>WHERE YOU CAN FIND MORE INFORMATION
</B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">We must comply with the informational requirements of the Securities Exchange Act of 1934, as amended, and we are
required to file reports and proxy statements and other information with the Securities and Exchange Commission. You may read and copy these reports, proxy statements and other information at the Public Reference Room maintained by the Securities
and Exchange Commission at 100 F Street, N.E., Washington, D.C. 20549. You may also obtain copies at the prescribed rates from the Public Reference Section of the Securities and Exchange Commission at its principal office in Washington, D.C. You may
call the Securities and Exchange Commission at 1-800-SEC-0330 for further information about the public reference room. The Securities and Exchange Commission also maintains a website that contains reports, proxy and information statements and other
information regarding issuers like us that file electronically with the Securities and Exchange Commission. You may access the Securities and Exchange Commission&#146;s web site at http://www.sec.gov. We maintain a website at
www.arrowheadresearch.com. The information contained in, or that can be accessed through, our website is not incorporated by reference herein and is not part of this prospectus. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Statements contained in this prospectus as to the contents of any contract or other document are not necessarily complete, and in each
instance we refer you to the copy of the contract or document filed as an exhibit to the registration statement, each such statement being qualified in all respects by such reference. </FONT></P>
<P STYLE="margin-top:24px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><A NAME="tx271952_13"></A>INCORPORATION OF CERTAIN INFORMATION BY REFERENCE </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The Securities and Exchange Commission allows us to incorporate by reference in this prospectus the information that we file with them.
Incorporation by reference means that we can disclose important information to you by referring you to other documents that are legally considered to be part of this prospectus. Later information that we file with the Securities and Exchange
Commission will automatically update and supersede the information in this prospectus, any supplement and the documents listed below. Our SEC file number is 0-21898. We incorporate by reference the specific documents listed below and any future
filings made with the Securities and Exchange Commission under Section&nbsp;13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934, as amended, until all of the shares of common stock and warrant shares covered by this prospectus are
sold: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">The Company&#146;s Annual Report on Form 10-K for the fiscal year ended September&nbsp;30, 2011, filed on December&nbsp;20, 2011;
</FONT></P></TD></TR></TABLE>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">10 </FONT></P>



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<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">The Company&#146;s Current Reports on Form 8-K filed on October&nbsp;6, 2011,&nbsp;October&nbsp;24, 2011 (as amended by the Company&#146;s Current
Report on Form 8-K/A filed on December 30, 2011),&nbsp;October&nbsp;26, 2011,&nbsp;October&nbsp;27, 2011,&nbsp;November&nbsp;15, 2011 and November&nbsp;17, 2011; </FONT></P></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">The description of the Company&#146;s common stock contained in its registration statement on Form 8-A/A (Registration No. 000-21898), filed on
November&nbsp;1, 2010, including any amendments or reports filed for the purpose of updating such description; and </FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="5%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">All documents filed by the Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act, after the date of the original Registration
Statement and prior to effectiveness of the registration statement of which this prospectus is a part, provided that all documents &#147;furnished&#148; by the Company to the SEC and not &#147;filed&#148; are not deemed incorporated by reference
herein. </FONT></P></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">We will furnish without charge to each person, including any beneficial owner, to whom this
prospectus is delivered, upon written or oral request, a copy of any document incorporated by reference. Requests should be addressed to Corporate Secretary, 225 South Lake Street, Suite 300, Pasadena, CA 91101 or may be made telephonically at
(626)&nbsp;304-3400. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">You should rely only on the information incorporated by reference or provided in this prospectus or any
prospectus supplement. We have not authorized anyone to provide you with different information. You should not assume that the information contained in this prospectus or the accompanying prospectus supplement 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. </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">11 </FONT></P>



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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>PART II </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>INFORMATION NOT REQUIRED IN PROSPECTUS </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Item&nbsp;14.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Other Expenses of Issuance and Distribution (1). </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">The following are the estimated expenses of the distribution of the shares registered hereunder on Form&nbsp;S-3: </FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD WIDTH="90%"></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD></TD>
<TD></TD>
<TD></TD></TR>


<TR BGCOLOR="#cceeff">
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Registration Fee&#151;Securities and Exchange Commission</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2"> 1,643.36</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Accountants Fees and Expenses</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">10,000</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR BGCOLOR="#cceeff">
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Legal Fees and Expenses</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">10,000</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Miscellaneous</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">10,000</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR STYLE="font-size:1px">
<TD VALIGN="bottom"></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom"> <P STYLE="border-top:1px solid #000000">&nbsp;</P></TD>
<TD VALIGN="bottom"> <P STYLE="border-top:1px solid #000000">&nbsp;</P></TD>
<TD>&nbsp;</TD></TR>
<TR BGCOLOR="#cceeff">
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Total</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2">31,643.36</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;</FONT></TD></TR>
<TR STYLE="font-size:1px">
<TD VALIGN="bottom"></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom"> <P STYLE="border-top:1px solid #000000">&nbsp;</P></TD>
<TD VALIGN="bottom"> <P STYLE="border-top:1px solid #000000">&nbsp;</P></TD>
<TD>&nbsp;</TD></TR>
</TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">The amounts set forth below, except for the SEC Registration Fee, are estimated. </FONT></TD></TR></TABLE>
<P STYLE="font-size:18px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Item&nbsp;15.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Indemnification of Directors and Officers. </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">The Company&#146;s Certificate of Incorporation provides for the elimination of personal monetary liability of directors to the fullest extent permissible under Delaware law. Delaware law does not permit
the elimination or limitation of director monetary liability for: (i)&nbsp;breaches of the director&#146;s duty of loyalty to the corporation or its stockholders; (ii)&nbsp;acts or omissions not in good faith or involving intentional misconduct or
knowing violations of law; (iii)&nbsp;the payment of unlawful dividends or unlawful stock repurchases or redemptions or (iv)&nbsp;transactions in which the director received an improper personal benefit. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Section&nbsp;145 of the Delaware General Corporation Law permits a Delaware corporation to indemnify, on certain terms and conditions,
any person who was or is a party or is threatened to be made a party to any threatened pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative, by reason of the fact that he is or was a director,
officer, employee or agent of the corporation or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against expenses (including
attorneys&#146; fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him in connection with such action. The Certificate of Incorporation and Bylaws of the Company require the Company to indemnify the
Company&#146;s directors and officers to the fullest extent permitted under Delaware law. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Insofar as indemnification for
liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Company pursuant to the foregoing provisions, the Company has been advised that in the opinion of the SEC such indemnification is
against public policy as expressed in the Securities Act and is, therefore, unenforceable. </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">II-1
</FONT></P>


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<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Item&nbsp;16.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Exhibit Index. </B></FONT></TD></TR></TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="5%"></TD>
<TD WIDTH="92%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1">Exhibit</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000;width:23pt" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1">No.</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="border-bottom:1px solid #000000;width:37pt"><FONT STYLE="font-family:Times New Roman" SIZE="1">Description</FONT></P></TD></TR>


<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">4.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Common Stock Certificate (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Ropes &amp; Gray LLP (2)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Rose, Snyder &amp; Jacobs, the registrant&#146;s independent registered public accounting firm**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Ropes &amp; Gray LLP (included in legal opinion filed as Exhibit 5.1) (2)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">24.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Power of Attorney (included on signature page) (2)</FONT></TD></TR>
</TABLE>  <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">**</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Filed herewith. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Incorporated by reference from Amendment No.&nbsp;2 to the Registration Statement on Form S-1, filed by the registrant on September&nbsp;11, 2009.
</FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Incorporated by reference from the Registration Statement on Form S-3 (File No 333-178532), filed by the Registrant on December 15, 2011. </FONT></TD></TR></TABLE>
<P STYLE="font-size:18px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Item&nbsp;17.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Undertakings. </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><I>Item&nbsp;512(a) of
Regulation S-K</I>. The undersigned registrant hereby undertakes: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement: </FONT></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(i)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">To include any prospectus required by Section&nbsp;10(a)(3) of the Securities Act of 1933; </FONT></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(ii)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof)
which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of
securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the
aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the &#147;Calculation of Registration Fee&#148; table in the effective registration statement; and
</FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(iii)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such
information in the registration statement; </FONT></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><I>Provided, however</I>, That: </FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px; text-indent:8%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) of this section do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section&nbsp;13 or Section&nbsp;15(d) of the Securities Exchange Act of 1934 that are incorporated by
reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement. </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial <I>bona fide</I> offering thereof. </FONT></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(3)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.
</FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(4)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser: </FONT></TD></TR></TABLE>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">II-2
</FONT></P>


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<h5 align="left"><a href="#toc">Table of Contents</a></h5>


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(A)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was
deemed part of and included in this registration statement; and </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(B)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering
made pursuant to Rule 415(a)(1)(i), (vii), or (x)&nbsp;for the purpose of providing the information required by Section&nbsp;10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the
earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any
person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such
securities at that time shall be deemed to be the initial <I>bona fide</I> offering thereof. <I>Provided, however</I>, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document
incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any
statement that was made in the registration statement or prospectus that was part of this Registration Statement or made in any such document immediately prior to such effective date. </FONT></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(5)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities:
</FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">The undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant
pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned
registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(i)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424; </FONT></TD></TR></TABLE>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(ii)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;
</FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(iii)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by
or on behalf of the undersigned registrant; and </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(iv)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser. </FONT></TD></TR></TABLE>
<P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><I>Item&nbsp;512(b) of Regulation S-K</I>. The undersigned registrant hereby undertakes that, for purposes of determining any liability under the
Securities Act of 1933, each filing of the registrant&#146;s annual report pursuant to Section&nbsp;13(a) or Section&nbsp;15(d) of the Securities Exchange Act of 1934, as amended (and, where applicable, each filing of an employee benefit plan&#146;s
annual report pursuant to Section&nbsp;15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and
the offering of such securities at that time shall be deemed to be the initial <I>bona fide</I> offering thereof. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><I>Item&nbsp;512(h) of
Regulation S-K</I>. Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act, and is, therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the registrant of expenses incurred or </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">II-3
</FONT></P>


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<h5 align="left"><a href="#toc">Table of Contents</a></h5>

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">
paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification
by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue. </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">II-4
</FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>SIGNATURES </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it
meets all of the requirements for filing on Form&nbsp;S-3 and has duly caused this Amendment No. 1 to registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the city of Pasadena, state of California, on
January 25, 2012. </FONT></P>  <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>  <DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE">


<TR>
<TD WIDTH="6%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="92%"></TD></TR>


<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>ARROWHEAD RESEARCH CORPORATION</B></FONT></P></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">By:</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/&nbsp;&nbsp;Kenneth A. Myszkowski</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Kenneth A. Myszkowski</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Chief Financial Officer</FONT></P></TD></TR>
</TABLE></DIV>    <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE">


<TR>
<TD WIDTH="37%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="44%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="15%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Signature</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Title</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Date</B></FONT></P></TD></TR>


<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp; Christopher Anzalone</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Christopher Anzalone</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Chief Executive Officer and President and Director</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">(Principal Executive Officer)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 25, 2012</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-bottom:0px;margin-top:0px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">R. Bruce Stewart</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Executive Chairman of the Board</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 25, 2012</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp; Kenneth A. Myszkowski</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Kenneth A. Myszkowski</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Chief Financial Officer</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">(Principal Financial Officer and Principal Accounting Officer)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 25, 2012</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-bottom:0px;margin-top:0px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Edward W. Frykman</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 25, 2012</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-bottom:0px;margin-top:0px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Charles P. McKenney</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 25, 2012</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-bottom:0px;margin-top:0px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Mauro Ferrari</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 25, 2012</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-bottom:0px;margin-top:0px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Douglass Given</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 25, 2012</FONT></TD></TR>
</TABLE>  <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TR>
<TD WIDTH="10%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="89%"></TD></TR>


<TR>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">*&nbsp;By:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/&nbsp;&nbsp;Kenneth A. Myszkowski</FONT></P></TD></TR>
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<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Kenneth A. Myszkowski</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Attorney in fact</FONT></TD></TR>
</TABLE>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">II-5
</FONT></P>


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<h5 align="left"><a href="#toc">Table of Contents</a></h5>

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>EXHIBIT INDEX. </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD WIDTH="92%"></TD></TR>
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<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1">Exhibit</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000;width:23pt" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1">No.</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="border-bottom:1px solid #000000;width:37pt"><FONT STYLE="font-family:Times New Roman" SIZE="1">Description</FONT></P></TD></TR>


<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">4.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Common Stock Certificate (1)</FONT></TD></TR>
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<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Ropes &amp; Gray LLP (2)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Rose, Snyder &amp; Jacobs, the registrant&#146;s independent registered public accounting firm**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Ropes &amp; Gray LLP (included in legal opinion filed as Exhibit 5.1) (2)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">24.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Power of Attorney (included on signature page) (2)</FONT></TD></TR>
</TABLE>  <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">**</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Filed herewith. </FONT></TD></TR></TABLE>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Incorporated by reference from Amendment No.&nbsp;2 to the Registration Statement on Form S-1, filed by the registrant on September&nbsp;11, 2009.
</FONT></TD></TR></TABLE>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Incorporated by reference from the Registration Statement on Form S-3 (File No 333-178532), filed by the Registrant on December 15, 2011. </FONT></TD></TR></TABLE>

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 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">II-6
</FONT></P>

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<TYPE>EX-23.1
<SEQUENCE>2
<FILENAME>d271952dex231.htm
<DESCRIPTION>CONSENT OF ROSE, SNYDER & JACOBS
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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Exhibit 23.1 </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">We hereby consent to the
incorporation by reference, in this Registration Statement on Amendment No. 1 to Form S-3 of our report dated December&nbsp;20, 2011, with respect to the consolidated financial statements of Arrowhead Research Corporation and Subsidiaries appearing
in the Company&#146;s Annual Report on Form 10-K for the year ended September&nbsp;30, 2011, and to the reference of our Firm under the caption &#147;Experts&#148; in the Registration Statement. </FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/ &nbsp;&nbsp;&nbsp;&nbsp;Rose, Snyder&nbsp;&amp; Jacobs</FONT></P></TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Rose, Snyder&nbsp;&amp; Jacobs </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">A Corporation of Certified Public Accountants </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Encino, California </FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">January 24, 2012 </FONT></P>
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