<SUBMISSION>
<ACCESSION-NUMBER>0001193125-05-172419
<TYPE>SC 13D
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20050822
<DATE-OF-FILING-DATE-CHANGE>20050822
<SUBJECT-COMPANY>
<COMPANY-DATA>
<CONFORMED-NAME>AEROGEN INC
<CIK>0001039160
<ASSIGNED-SIC>3841
<IRS-NUMBER>330488580
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC 13D
<ACT>34
<FILE-NUMBER>005-60561
<FILM-NUMBER>051041095
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>2071 STIERLIN COURT
<CITY>MOUNTAIN VIEW
<STATE>CA
<ZIP>94043
<PHONE>650 864-7300
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2071 STIERLIN COURT
<CITY>MOUNTAIN VIEW
<STATE>CA
<ZIP>94043
</MAIL-ADDRESS>
</SUBJECT-COMPANY>
<FILED-BY>
<COMPANY-DATA>
<CONFORMED-NAME>NEKTAR THERAPEUTICS
<CIK>0000906709
<ASSIGNED-SIC>2834
<IRS-NUMBER>943134940
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC 13D
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>150 INDUSTRIAL RD
<CITY>SAN CARLOS
<STATE>CA
<ZIP>94070
<PHONE>6506313100
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>150 INDUSTRIAL ROAD
<CITY>SAN CARLOS
<STATE>CA
<ZIP>94070
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>INHALE THERAPEUTIC SYSTEMS INC
<DATE-CHANGED>19980723
</FORMER-COMPANY>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>INHALE THERAPEUTIC SYSTEMS
<DATE-CHANGED>19940303
</FORMER-COMPANY>
</FILED-BY>
<DOCUMENT>
<TYPE>SC 13D
<SEQUENCE>1
<FILENAME>dsc13d.htm
<DESCRIPTION>SCHEDULE 13D
<TEXT>
<HTML><HEAD>
<TITLE>Schedule 13D</TITLE>
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</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</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 FACE="Times New Roman" SIZE="4"><B>UNITED STATES </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="4"><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>Washington, D.C. 20549 </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"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>SCHEDULE 13D </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"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="3"><B>Under the Securities Exchange Act of 1934* </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"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</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 FACE="Times New Roman"
SIZE="2">Aerogen, Inc. </FONT></P><HR SIZE="1" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Name of Issuer) </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"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="2">Common Stock, $0.001 par value per share </FONT></P><HR SIZE="1" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Title of Class of Securities)
</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"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2">007779309 </FONT></P><HR SIZE="1" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(CUSIP Number) </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"><FONT SIZE="1">&nbsp;</FONT></P>
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<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Nektar Therapeutics</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="2">150 Industrial Road</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">San Carlos, CA 94070</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2">(650) 631-3100</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Attn: Nevan Elam, Senior Vice President Corporate</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Operations and General Counsel</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">with a copy to:</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="2">Wilson Sonsini Goodrich &amp; Rosati</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Professional Corporation</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">650 Page Mill Road</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Palo Alto, CA 94304</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">(650) 493-9300</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Attn: Martin
Korman</FONT></P></TD></TR>
</TABLE><HR SIZE="1" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications) </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"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">August 12, 2005 </FONT></P><HR SIZE="1" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>(Date of Event which Requires Filing of this Statement) </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"><FONT
FACE="Times New Roman" SIZE="2">If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of &#167;&#167;240.13d-1(e), 240.13d-1(f)
or 240.13d-1(g), check the following box.&nbsp;&nbsp;</FONT><FONT FACE="WINGDINGS" SIZE="2" COLOR="#000000">&#168;</FONT><FONT FACE="Times New Roman" SIZE="2"> </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>Note:</B>&nbsp;&nbsp; Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See &#167;240.13d-7
for other parties to whom copies are to be sent. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
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<TD WIDTH="1%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">*</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">The remainder of this cover page shall be filled out for a Reporting Person&#146;s initial filing on this form with respect to the subject class of securities, and for any
subsequent amendment containing information which would alter disclosures provided in a prior cover page. </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"><FONT FACE="Times New Roman" SIZE="2">The information required on the remainder of this cover page shall not be deemed to be &#147;filed&#148; for the purpose of Section 18 of the Securities Exchange Act of
1934 (&#147;Act&#148;) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). </FONT></P>

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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">CUSIP No. 007779309 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P>
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<TD VALIGN="top" STYLE="BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;1.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Name of Reporting Person. I.R.S. Identification Nos. of above persons (entities
only).</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Nektar Therapeutics (I.R.S. Identification No. 94-3134940)</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
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<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;2.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Check the Appropriate Box if a Member of a Group (See Instructions)</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">(a)&nbsp;&nbsp;</FONT><FONT FACE="WINGDINGS" SIZE="2" COLOR="#000000">&#168;</FONT><FONT FACE="Times New Roman" SIZE="2"></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">(b)&nbsp;&nbsp;</FONT><FONT FACE="WINGDINGS" SIZE="2" COLOR="#000000">&#168;</FONT><FONT FACE="Times New Roman" SIZE="2"></FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;3.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">SEC Use Only</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT SIZE="1">&nbsp;</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;4.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Source of Funds (See Instructions)</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;OO</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;5.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px"><FONT SIZE="1">&nbsp;</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="right" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2"></FONT><FONT FACE="WINGDINGS" SIZE="2" COLOR="#000000">&#168;</FONT><FONT FACE="Times New Roman" SIZE="2"></FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;6.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Citizenship or Place of Organization</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Delaware</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
</TABLE>
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<TR>
<TD WIDTH="9%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="90%"></TD></TR>
<TR>
<TD VALIGN="middle" ALIGN="center" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Number&nbsp;of</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Shares</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Beneficially</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Owned&nbsp;by</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Each</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Reporting</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Person</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">With</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;7.&nbsp;&nbsp;&nbsp;&nbsp;Sole Voting Power</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2">&nbsp;&nbsp;8.&nbsp;&nbsp;&nbsp;&nbsp;Shared Voting Power</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT
FACE="Times New Roman" SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9,697,782</FONT><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><SUP>1</SUP></FONT><FONT FACE="Times New Roman"
SIZE="3" COLOR="#000000"></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;9.&nbsp;&nbsp;&nbsp;&nbsp;Sole Dispositive Power</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2">10.&nbsp;&nbsp;&nbsp;&nbsp;Shared Dispositive Power</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT
FACE="Times New Roman" SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0</FONT></P></TD></TR>
</TABLE>
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<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="90%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="6%"></TD></TR>
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<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">11.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Aggregate Amount Beneficially Owned by Each Reporting Person</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9,697,782</FONT><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><SUP>1</SUP></FONT><FONT FACE="Times New Roman" SIZE="3" COLOR="#000000"></FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">12.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px"><FONT SIZE="1">&nbsp;</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">13.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Percent of Class Represented by Amount in Row (11)</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;56.0%</FONT><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><SUP>2</SUP></FONT><FONT FACE="Times New Roman" SIZE="3" COLOR="#000000"></FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">14.</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Type of Reporting Person (See Instructions)</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>CO</B></FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
</TABLE><HR WIDTH="8%" SIZE="1" NOSHADE COLOR="#000000" ALIGN="left">
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"></FONT><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><SUP>1</SUP></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><SUP></SUP></FONT><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">9,697,782 shares of Aerogen, Inc. (&#147;Aerogen&#148;) Common Stock are subject to voting
agreements (&#147;Voting Agreements&#148;) between Reporting Person and certain officers, directors and stockholders of Aerogen, as described in Item 6 below, of which: (i) 709,755 shares are outstanding as of August 12, 2005, (ii) 4,886,540 shares
are issuable upon conversion of shares of Series A-1 Preferred Stock which are convertible within 60 days of August 12, 2005, (iii) 3,663,789 shares are issuable upon exercise of outstanding warrants which are exercisable within 60 days of August
12, 2005, and (iv) 437,698 shares are issuable upon exercise of outstanding options which are exercisable within 60 days of August 12, 2005. Beneficial ownership of the Common Stock referred to herein is being reported hereunder solely because
Reporting Person may be deemed to have beneficial ownership of such shares as a result of the Voting Agreements. Neither the filing of this Statement on Schedule 13D nor any of its contents shall be deemed to constitute an admission by Reporting
Person that it is the beneficial owner of any of the Common Stock referred to herein for purposes of Section 13(d) or 13(g) of the Securities Exchange Act of 1934, as amended, or for any other purpose, and such beneficial ownership is expressly
disclaimed. </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 FACE="Times New Roman" SIZE="2"></FONT><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><SUP>2</SUP></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><SUP></SUP></FONT><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">Based on the 17,325,273 shares of Common Stock outstanding as of August 12, 2005 assuming the
issuance of the shares described in clauses (ii) through (iv) of footnote (1). </FONT></TD></TR></TABLE>

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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Schedule 13D </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>Item 1. Security and Aerogen </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The class of equity securities to which this Schedule 13D relates is the Common Stock, $0.001 par value per share (the &#147;Common Stock&#148;), of
Aerogen, Inc., a Delaware corporation (&#147;Aerogen&#148;), with its principal executive office at 2071 Stierlin Court, Mountain View, California, 94043. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>Item 2. Identity and Background </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">This Schedule 13D is being filed on behalf of Nektar Therapeutics, a Delaware corporation (&#147;Reporting Person&#148;), with its principal executive
office at 150 Industrial Road, San Carlos, California 94070. Reporting Person enables the development of differentiated pharmaceutical products using its advanced proprietary drug delivery technologies and services. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Set forth on Annex A to this Schedule 13D is a chart setting forth, with
respect to each executive officer, director and controlling person of Reporting Person, his or her name, residence or business address, present principal occupation or employment (along with the name, principal business and address of any
corporation or other organization in which such employment is conducted) and citizenship, in each case as of the date hereof. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">During the last five years, neither Reporting Person nor, to the knowledge of Reporting Person, any executive officer, director or controlling person of
Reporting Person named on Annex A has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors). </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">During the last five years, neither Reporting Person nor, to the knowledge of Reporting Person, any executive officer, director or controlling person of
Reporting Person named on Annex A is or has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future
violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">To the knowledge of Reporting Person, each of the individuals set forth on Annex A is a citizen of the United States. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>Item 3. Source and Amount of funds or Other Consideration </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Reporting Person, Aerogen and Oski Acquisition Corporation, a Delaware
corporation and an indirect wholly-owned subsidiary of Reporting Person (&#147;Merger Sub&#148;), entered into an Agreement and Plan of Merger dated as of August 12, 2005 (the &#147;Merger Agreement&#148;), which is included as Exhibit 1 in this
Schedule 13D. Pursuant to the Merger Agreement, Merger Sub will be merged with and into Aerogen and Aerogen will continue as the surviving corporation and an indirect wholly-owned subsidiary of Reporting Person (the &#147;Merger&#148;), as described
in Item 4 below. The consummation of the Merger is subject to the approval of the stockholders of Aerogen and other customary closing conditions. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">As a condition and inducement to Reporting Person&#146;s willingness to enter into the Merger Agreement, certain officers, directors and other
stockholders (each a &#147;Stockholder&#148; and collectively, the &#147;Stockholders&#148;) of Aerogen entered into individual voting agreements with Reporting Person, each dated as of August 12, 2005, a form of which is included as Exhibit 2 in
this Schedule 13D (each, a &#147;Voting Agreement&#148; and collectively, the &#147;Voting Agreements&#148;) and more fully described in Item 6, whereby each Stockholder has agreed to vote all of the shares of Aerogen capital stock beneficially
owned (as defined in Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the &#147;Act&#148;)) by such Stockholder, and all additional securities of Aerogen of which Stockholder acquires beneficial ownership during the period from the
date of the Voting Agreement through the Expiration Date (as defined in Item 6 below) in favor of adoption and approval of the Merger Agreement and approval of the Merger and certain related matters. The Voting Agreements also contain certain
restrictions on the ability of the Stockholders to transfer the shares subject to the Voting Agreements or the voting rights in respect of such shares. </FONT></P>

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 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Reporting Person did not pay additional consideration to any Stockholder in connection with the execution
and delivery of the Voting Agreements. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">References to and
descriptions of the Merger, the Merger Agreement and the Voting Agreements set forth herein are qualified in their entirety by reference to the Merger Agreement and the form of Voting Agreement included as Exhibits 1 and 2 to this Schedule 13D,
respectively, which are incorporated by reference herein in their entirety. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2"><B>Item 4: Purpose of Transaction </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">As described
in Item 3 above, this Schedule 13D relates to the acquisition of Aerogen by Reporting Person pursuant to a statutory merger of Merger Sub with and into Aerogen, pursuant to which, at the effective time of the Merger, the separate existence of Merger
Sub will cease and Aerogen will continue as the surviving corporation. By virtue of the Merger, each share of outstanding Series A-1 Preferred Stock of Aerogen will be converted into the right to receive (i) cash in an amount of $7.2563 and (ii) at
Reporting Person&#146;s election, $21.7688 in cash or the number of shares of common stock of Reporting Person equal to quotient obtained by <I>dividing</I> $21.7688 <I>by</I> the volume weighted average price per share of the common stock of
Reporting Person, as reported by the Nasdaq National Market, for the 20 trading day period ending on the second trading day preceding the date on which the Merger is consummated. In addition, each share of outstanding Common Stock of Aerogen will be
at the effective time of the Merger converted into the right to receive (y) cash in an amount equal to $0.1875 and (z) at Reporting Person&#146;s election, $0.5625 in cash or the number of shares of common stock of Reporting Person equal to the
quotient obtained by <I>dividing</I> $0.5625 <I>by </I>such volume weighted average price. Options and warrants to purchase Aerogen Common Stock that are outstanding at the effective time of the Merger will be cancelled and terminated and a holder
of any such option or warrant will receive, with respect to any share of Aerogen Common Stock subject to such option or warrant, an amount in cash equal to the excess, if any, of (x) $0.75 over (y) the exercise price payable in respect of such share
of Common Stock issuable under such option or warrant, as the case may be. Also, the rights of participants in Aerogen&#146;s 2000 Employee Stock Purchase Plan (the &#147;ESPP&#148;) with respect to any offering period underway immediately prior to
the effective time of the Merger under the ESPP will be determined by treating the last business day prior to the effective time of the Merger as the last day of such offering period and by making such other pro-rata adjustments as may be necessary
to reflect the shortened offering period but otherwise treating such shortened offering period as a fully effective and completed offering period for all purposes under the ESPP. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Pursuant to the terms of the Merger Agreement, upon the consummation of the Merger, the directors and officers of Merger Sub
immediately prior to the effective time of the Merger will be the directors and officers, respectively, of the surviving corporation in the Merger. In addition, upon consummation of the Merger, the certificate of incorporation and bylaws of Aerogen
will be amended and restated as set forth in the Merger 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; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2">The purpose of the Voting Agreements is to assist Aerogen and Reporting Person in consummating the Merger and the other transactions contemplated under the Merger Agreement. The Voting Agreements are more fully described in Item 6 below.
</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Upon consummation of the Merger, Aerogen&#146;s Common Stock
will become eligible for termination of registration pursuant to Section 12(g)(4) of the Act. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">References to and descriptions of the Merger, the Merger Agreement and the Voting Agreements set forth herein are qualified in their entirety by reference to the Merger Agreement and the form of Voting Agreement
included as Exhibits 1 and 2 to this Schedule 13D, respectively, which are incorporated by reference herein in their entirety. </FONT></P>

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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>Item 5. Interest in Securities of Aerogen </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT
SIZE="1">&nbsp;</FONT></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 FACE="Times New Roman" SIZE="2">(a)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">As a result of the Voting Agreements, Reporting Person may be deemed to be the beneficial owner of at least 9,697,782 shares of Aerogen Common Stock as of August 12, 2005. Such
Common Stock constitutes approximately 56.0% of the issued and outstanding shares of Aerogen Common Stock, based on 8,337,246 shares of Aerogen Common Stock issued and outstanding as of August 12, 2005 (as represented by Aerogen in the Merger
Agreement) and assuming the issuance of (i) 4,886,540 shares of Common Stock upon conversion of shares of Series A-1 Preferred Stock which are convertible within 60 days of August 12, 2005, (ii) 3,663,789 shares of Common Stock upon exercise of
outstanding warrants which are exercisable within 60 days of August 12, 2005, and (iii) 437,698 shares of Common Stock issuable upon exercise of outstanding options which are exercisable within 60 days of August 12, 2005. </FONT></TD></TR></TABLE>
<P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></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 FACE="Times New Roman" SIZE="2">(b)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Reporting Person has the shared power to vote or to direct the vote of the foregoing shares with respect to the matters described in Item 6. However, (a) other than as specifically
set forth in the Voting Agreements, Reporting Person is not entitled to any rights as a stockholder of Aerogen as to the foregoing shares, and (b) neither the filing of this Schedule 13D nor any of its contents shall be deemed to constitute an
admission by Reporting Person that it is the beneficial owner of any of the Common Stock referred to herein for purposes of Section 13(d) or 13(g) of the Act or for any other purpose, and such beneficial ownership is expressly disclaimed.
</FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></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 FACE="Times New Roman" SIZE="2">(c)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">No transactions in Aerogen&#146;s Common Stock were effected during the past 60 days or since the most recent filing of Schedule 13D, whichever is less, by the persons named in
response to Item 5(a), except for the entering into of the Merger Agreement and Voting Agreements. </FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></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 FACE="Times New Roman" SIZE="2">(d)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">To the knowledge of Reporting Person, no other person has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the securities
of Aerogen. </FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></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 FACE="Times New Roman" SIZE="2">(e)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Not applicable. </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"><FONT
FACE="Times New Roman" SIZE="2"><B>Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of Aerogen </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">See Items 3 and 4 above. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">In connection with the Merger Agreement, and as a condition and inducement to Reporting Person&#146;s willingness to enter into the Merger Agreement, the
following Stockholders entered into individual Voting Agreements with Reporting Person, each dated as of August 12, 2005: Jane E. Shaw Carpenter; Yehuda and Zipora Ivri; John Power; Xmark Fund, L.P.; Xmark Fund, Ltd.; Caduceus Capital II, LP;
Caduceus Capital Master Fund Limited; UBS Eucalyptus Fund LLC; Finsbury Worldwide Pharmaceutical Trust; HFC SHC Aggressive Master Fund; HealthCap IV Bis, L.P.; HealthCap IV, L.P. and HealthCap IV KB. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The Voting Agreements contain restrictions on the ability of the Stockholders
to transfer the shares subject to the Voting Agreements or the voting rights in respect of such shares (other than transfers to a Stockholder&#146;s affiliates) during the period beginning on the date of the Voting Agreement and ending on the
earlier of: the date on which the Merger Agreement is terminated and the effective date of the Merger (such earlier date, the &#147;Expiration Date&#148;). In addition, the Voting Agreements provide that prior to the Expiration Date and at any
meeting and in any written action by consent of the stockholders of Aerogen, each Stockholder will vote, or cause to be voted all of the capital stock beneficially owned by such Stockholder, (i) in favor of adoption of the Merger Agreement, each of
the transactions contemplated by the Merger Agreement and any action in furtherance of the foregoing; (ii) against any of the following actions (in each case excluding the Merger and the transactions contemplated by the Merger Agreement): any
merger, consolidation or other business combination involving Aerogen or any of its subsidiaries, any sale or other transfer of all or substantially all of the assets of Aerogen, any sale, lease, license or transfer of any significant part of the
assets of Aerogen, any reorganization, recapitalization, dissolution, liquidation or winding up of Aerogen, or any other action which is intended, or would reasonably be expected, to interfere with or delay in </FONT></P>

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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">any material respect the Merger or any of the other transactions contemplated by the Merger Agreement or the Voting
Agreements; (iii) in favor of approving a Certificate of Amendment to Aerogen&#146;s Certificate of Designations, Preferences and Rights of the Preferred Stock; and (iv) in favor of any action in furtherance of the foregoing matters described in
this paragraph. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">In connection with the Voting Agreements, each
Stockholder also executed and delivered to Reporting Person an irrevocable proxy with respect to all shares of Aerogen capital beneficially owned by such Stockholder as of the date of the Voting Agreements and thereafter acquired. The irrevocable
proxies allow the Chief Executive Officer and Vice President of Corporate Operations of Reporting Person to vote the shares subject to such proxies as set forth above. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">References to and descriptions of the Voting Agreements set forth herein are qualified in their entirety by reference to the
form of Voting Agreement included as Exhibit 2 to this Schedule 13D, which is incorporated by reference herein in its entirety. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Except as described in this Schedule 13D, there are no contracts, arrangements, understandings or relationships (legal or otherwise) among Reporting
Person and any other person with respect to any securities of Aerogen, including but not limited to transfer or voting of any of the securities, finders fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits,
division of profits or loss, or the giving or withholding of proxies. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>Item
7. Material to Be Filed as Exhibits </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></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 FACE="Times New Roman" SIZE="2">1.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Agreement and Plan of Merger dated as of August 12, 2005, by and among Nektar Therapeutics, Oski Acquisition Corporation and Aerogen, Inc. (Incorporated by reference to Exhibit 2.1
to the Current Report on Form 8-K of Nektar Therapeutics, filed August 16, 2005 (Commission File No. 000-24006)). </FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></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 FACE="Times New Roman" SIZE="2">2.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Form of Voting Agreement. </FONT></TD></TR></TABLE>

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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B></B><B><I>Signature</I></B><B> </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"><FONT FACE="Times New Roman" SIZE="2">After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true,
complete and correct. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
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<TD WIDTH="100%"></TD></TR>
<TR>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">August 22, 2005</FONT></P><HR WIDTH="60%" SIZE="1" NOSHADE COLOR="#000000" ALIGN="left"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Date</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">/s/ N<SMALL>EVAN</SMALL> E<SMALL>LAM</SMALL></FONT></P><HR WIDTH="60%" SIZE="1" NOSHADE COLOR="#000000" ALIGN="left"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Signature</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Nevan Elam, Senior Vice President Corporate Operations and General Counsel</FONT></P><HR WIDTH="60%" SIZE="1" NOSHADE COLOR="#000000"
ALIGN="left"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Name/Title</FONT></TD></TR>
</TABLE>

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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><U>Annex A </U></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Set forth below is the name, business address, present principal occupation or employment and citizenship of each director and executive officer of
Reporting Person. The principal address of Reporting Person, and unless otherwise indicated below, the current business address for each individual listed below is 150 Industrial Road, San Carlos, California 94070. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="24%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="24%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="25%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="24%"></TD></TR>
<TR>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="1"><B>Name and Business Address</B></FONT></P><HR WIDTH="152" SIZE="1" NOSHADE ALIGN="left" COLOR="#000000"></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 FACE="Times New Roman" SIZE="1"><B>Position with Reporting Person</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></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 FACE="Times New Roman" SIZE="1"><B>Present Principal</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Occupation or</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Employment</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></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 FACE="Times New Roman" SIZE="1"><B>Citizenship</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Robert B. Chess</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Executive Chairman of the Board</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">See &#147;Position with Reporting Person&#148;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Ajit S. Gill</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Chief Executive Officer,</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2">President and Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">See &#147;Position with Reporting Person&#148;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Ajay Bansal</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Chief Financial Officer</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">See &#147;Position with Reporting Person&#148;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">John S. Patton, Ph.D.</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Chief Scientific Officer and</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">See &#147;Position with Reporting Person&#148;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">David Johnston, Ph.D.</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Senior&nbsp;Vice&nbsp;President,&nbsp;Research</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">and Development</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">See &#147;Position with Reporting Person&#148;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Nevan Elam</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Senior&nbsp;Vice&nbsp;President,&nbsp;Corporate</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Operations and General</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Counsel</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">See &#147;Position with Reporting Person&#148;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Michael A. Brown</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Retired</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Joseph J. Krivulka</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Retired</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></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"><FONT FACE="Times New Roman" SIZE="2">Christopher A. Kuebler</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">210 Carnegie Center</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Princeton, NJ 08540</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Chairman of the Board</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Covance, Inc.</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Irwin Lerner</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Retired</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Susan Wang</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Retired</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Roy A.Whitfield</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Retired</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">United States</FONT></TD></TR>
</TABLE>

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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>EXHIBIT 2 </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 FACE="Times New Roman" SIZE="2"><B>VOTING AGREEMENT </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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>T<SMALL>HIS</SMALL> V<SMALL>OTING</SMALL> A<SMALL>GREEMENT</SMALL></B><SMALL></SMALL> (&#147;Agreement&#148;) is entered into as of August 12, 2005, by
and between <B>N<SMALL>EKTAR</SMALL> T<SMALL>HERAPEUTICS</SMALL></B><SMALL></SMALL>, a Delaware corporation (&#147;Parent&#148;), and the undersigned (&#147;Stockholder&#148;). </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 FACE="Times New Roman" SIZE="2"><B>R<SMALL>ECITALS</SMALL> </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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>A.</B> Stockholder is a holder of record and the &#147;beneficial owner&#148; (within the meaning of Rule 13d-3 under the Securities Exchange Act of
1934) (&#147;Beneficial Owner&#148;) of certain shares of capital stock of Aerogen, Inc., a Delaware corporation (the &#147;Company&#148;). </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>B. </B>Parent, Oski Acquisition Corporation, a Delaware corporation (&#147;Merger Sub&#148;), and the Company are entering into an Agreement and Plan
of Merger of even date herewith (such executed agreement, with such amendments and modifications thereto as are consented to by the Stockholder, the &#147;Merger Agreement&#148;) which provides (subject to the conditions set forth therein) for the
merger of Merger Sub with and into the Company (the &#147;Merger&#148;). </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2"><B>C.</B> Stockholder is entering into this Agreement and, concurrently with the execution of this Agreement, into the proxy in the form attached hereto as Exhibit A (the &#147;Proxy&#148;) in order to induce Parent
to enter into the Merger 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 FACE="Times New Roman" SIZE="2"><B>A<SMALL>GREEMENT</SMALL>
</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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The parties to this Agreement, intending to be legally
bound, agree as follows: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>SECTION 1. C<SMALL>ERTAIN</SMALL>
D<SMALL>EFINITIONS</SMALL> </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">For purposes of this
Agreement: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(a)</B> <B></B><B><I>&#147;Company Common
Stock&#148;</I></B><B></B> shall mean the common stock, par value $0.001 per share, of the Company. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(b)</B> <B><I>&#147;Company Preferred Stock&#148;</I></B> shall mean the Preferred Stock, par value $0.001 per share, of the Company. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(c)</B> <B><I>&#147;Expiration Date&#148;</I></B> shall mean the earlier
of: (i) the date upon which the Merger Agreement is terminated; or (ii) the date upon which the Merger becomes effective, in each case, in accordance with the terms and conditions of the Merger 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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(d)</B> Stockholder shall be deemed to &#147;<B><I>Own</I></B>&#148; or to
have acquired &#147;<B><I>Ownership</I></B>&#148; of a security if Stockholder: (i) is the record owner of such security; or (ii) is the Beneficial Owner of such security. </FONT></P>

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 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(e)</B> <B><I>&#147;Person&#148;</I></B> shall mean any: (i) individual; (ii) corporation, limited
liability company, partnership or other entity; or (iii) governmental authority. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2"><B>(f)</B> <B><I>&#147;Subject Securities&#148;</I></B> shall mean: (i) all securities of the Company (including all shares of Company Common Stock, all shares of Company Preferred Stock and all options, warrants and
other rights to acquire shares of Company Common Stock or Company Preferred Stock) Owned by Stockholder as of the date of this Agreement; and (ii) all additional securities of the Company (including all additional shares of Company Common Stock, all
additional shares of Company Preferred Stock and all additional options, warrants and other rights to acquire shares of Company Common Stock or Company Preferred Stock) of which Stockholder acquires Ownership during the period from the date of this
Agreement through the Expiration 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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(g) </B>A Person
shall be deemed to have a effected a &#147;<B><I>Transfer</I></B>&#148; of a security if such Person: (i) sells, encumbers, grants an option with respect to or disposes of such security or any interest in such security to any Person other than
Parent; or (ii) enters into an agreement or commitment contemplating the possible sale of, encumbrance of, grant of an option with respect to or disposition of such security or any interest therein to any Person other than Parent. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(h) </B>Capitalized terms used but not otherwise defined in this Agreement
have the meanings assigned to such terms in the Merger 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"><FONT FACE="Times New Roman" SIZE="2"><B>SECTION
2. R<SMALL>ESTRICTIONS</SMALL> <SMALL>ON</SMALL> T<SMALL>RANSFER</SMALL> <SMALL>OF</SMALL> S<SMALL>UBJECT</SMALL> S<SMALL>ECURITIES</SMALL> <SMALL>AND</SMALL> V<SMALL>OTING</SMALL> R<SMALL>IGHTS</SMALL> </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>2.1 Restriction on Transfer of Subject Securities</B>.<B> </B>Subject to
Section 2.3, during the period from the date of this Agreement through the Expiration Date, Stockholder shall not cause or permit any Transfer of any of the Subject Securities to be effected. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>2.2 Restriction on Transfer of Voting Rights</B>. During the period from
the date of this Agreement through the Expiration Date, Stockholder shall ensure that: (a) none of the Subject Securities is deposited into a voting trust; and (b) no proxy is granted (other than in connection with Stockholder&#146;s compliance with
Section 3(a) and other than the Proxy delivered to Parent pursuant to Section 3(c)), and no voting agreement or similar agreement is entered into, with respect to any of the Subject Securities. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>2.3 Permitted Transfers</B>.<B> </B>Section 2.1 shall not prohibit a
Transfer of Subject Securities by Stockholder to an affiliate of Stockholder; <I>provided, however,</I> that a Transfer referred to in this sentence shall be permitted only if, as a precondition to such Transfer, the transferee agrees in a writing
reasonably satisfactory in form and substance to Parent, to be bound by all of the terms of this Agreement and concurrently delivers a duly executed proxy in the form attached hereto as Exhibit A with respect to such transferred Subject
Securities.<B></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"><FONT FACE="Times New Roman" SIZE="2"><B>SECTION 3. V<SMALL>OTING</SMALL> <SMALL>OF</SMALL>
S<SMALL>HARES</SMALL> </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(a) </B>Stockholder hereby
agrees that, prior to the Expiration Date, at any meeting of the stockholders of the Company (and at every adjournment and postponement thereof), however called, and in any written action by consent of stockholders of the Company, </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 FACE="Times New Roman" SIZE="2">2. </FONT></P>


<p Style='page-break-before:always'>
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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">unless otherwise directed in writing by Parent, Stockholder shall vote or cause all issued and outstanding shares of
Company Common Stock and Company Preferred Stock Owned by Stockholder to be voted: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(i) </B>in favor of: (i) the adoption of the Merger Agreement; (ii) each of the other transactions contemplated by the Merger
Agreement; and (iii) any action in furtherance of any of the foregoing; </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2"><B>(ii) </B>against the following actions (other than the Merger and the transactions contemplated by the Merger Agreement): (i) any merger, consolidation or other business combination involving the Company or any
subsidiary of the Company; (ii) any sale or other transfer of all or substantially all of the assets of the Company and its subsidiaries taken as a whole; (iii) any sale, lease, license or transfer of any significant part of the assets of the
Company or any subsidiary of the Company; (iv) any reorganization, recapitalization, dissolution, liquidation or winding up of the Company or any subsidiary of the Company; or (v) any other action which is intended, or would reasonably be expected,
to interfere with or delay in any material respect the Merger or any of the other transactions contemplated by the Merger Agreement or this Agreement (including any action or agreement that would result in a breach of any representation, warranty,
covenant, agreement or other obligation of the Company in the Merger Agreement); and </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(iii) </B>in favor of: (i) approving a Certificate of Amendment to the Company&#146;s Certificate of Designations, Preferences and
Rights of the Preferred Stock in the form of Exhibit B hereto; and (ii) any action in furtherance of the foregoing.<B></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; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(b) </B>Stockholder has delivered to Parent a duly executed Proxy, such Proxy covering the Subject Securities. Upon the execution of this Agreement by
Stockholder, Stockholder hereby revokes any and all prior proxies or powers of attorney given by Stockholder with respect to voting of the Subject Securities on the matters referred to in Section 3(a). Prior to the Expiration Date, Stockholder shall
not enter into any agreement or understanding with any person to vote or give instructions in any manner inconsistent with this Section 3.<B></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"><FONT FACE="Times New Roman" SIZE="2"><B>SECTION 4. W<SMALL>AIVER</SMALL> <SMALL>OF</SMALL> A<SMALL>PPRAISAL</SMALL> R<SMALL>IGHTS</SMALL> </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Stockholder hereby waives any rights of appraisal and any dissenters&#146; rights relating to the Merger on the terms and
conditions set forth in the Merger Agreement that Stockholder may have by virtue of, or with respect to, any shares of Company Common Stock or Company Preferred Stock Owned by Stockholder. </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 FACE="Times New Roman" SIZE="2">3. </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>SECTION 5. R<SMALL>EPRESENTATIONS</SMALL> <SMALL>AND</SMALL> W<SMALL>ARRANTIES</SMALL> <SMALL>AND</SMALL>
C<SMALL>OVENANTS</SMALL> <SMALL>OF</SMALL> S<SMALL>TOCKHOLDER</SMALL> </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">Stockholder hereby represents and warrants to Parent as follows: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>5.1 Authorization, etc</B>. Stockholder has the corporate right, power and authority to execute and deliver this Agreement and the Proxy and to perform
Stockholder&#146;s obligations hereunder and thereunder. This Agreement and the Proxy have been duly executed and delivered by Stockholder and constitute the legal, valid and binding obligation of Stockholder, enforceable against Stockholder in
accordance with its terms, subject to: (a) laws of general application relating to bankruptcy, insolvency and the relief of debtors; and (b) rules of law governing specific performance, injunctive relief and other equitable remedies. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>5.2 No Conflicts or Consents. </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(a) </B>The execution and delivery of this Agreement and the Proxy by
Stockholder do not, and the performance of this Agreement by Stockholder will not: (i) conflict with or violate any law, rule, regulation, order, decree or judgment applicable to Stockholder or by which Stockholder or any of Stockholder&#146;s
properties is or may be bound or affected; or (ii) result in or constitute (with or without notice or lapse of time) any breach of or default under, or give to any other Person (with or without notice or lapse of time) any right of termination,
amendment, acceleration or cancellation of, or result (with or without notice or lapse of time) in the creation of any encumbrance or restriction on any of the Subject Securities pursuant to, any Contract to which Stockholder is a party or by which
Stockholder or any of Stockholder&#146;s affiliates or properties is or may be bound or affected. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(b) </B>The execution and delivery of this Agreement and the Proxy by Stockholder do not, and the performance of this Agreement by Stockholder will
not, require any consent or approval of any Person. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>5.3
Title to Securities</B>. As of the date of this Agreement: (a) Stockholder holds of record (free and clear of any encumbrances) the number of outstanding shares of Company Common Stock set forth under the heading &#147;Common Shares Held of
Record&#148; on the signature page hereof; (b) Stockholder holds of record (free and clear of any encumbrances) the number of outstanding shares of Company Preferred Stock set forth under the heading &#147;Preferred Shares Held of Record&#148; on
the signature page hereof; (c) Stockholder holds (free and clear of any encumbrances) the options, warrants and other rights to acquire shares of Company Common Stock set forth under the heading &#147;Options and Other Rights&#148; on the signature
page hereof; (d) (d) Stockholder Owns the additional securities of the Company set forth under the heading &#147;Additional Securities Beneficially Owned&#148; on the signature page hereof; and (e) Stockholder does not Own any shares of capital
stock or other securities of the Company, or any option, warrant or other right to acquire any shares of capital stock or other securities of the Company, other than the shares and options, warrants and other rights set forth on the signature page
hereof. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>5.4 Certain Restrictions. </B>Stockholder agrees
that it will not bring, commence, institute, maintain, prosecute, participate in or voluntarily aid any action, claim, suit or cause of action, in law or in equity, in any court or before any governmental entity, which (i) challenges the validity of
or seeks to enjoin the operation of any provision of this Agreement or (ii) alleges that the execution and delivery of this Agreement by Stockholder, either alone or together with the other Company voting agreements and proxies to be delivered in
connection with the execution of the Merger Agreement, or the approval of the Merger Agreement by the board of directors of the Company on August 12, 2005, breaches any fiduciary duty of the board of directors of the Company or any member thereof.
</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 FACE="Times New Roman" SIZE="2">4. </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>SECTION 6. M<SMALL>ISCELLANEOUS</SMALL> </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.1 Further Assurances; Consents and Waivers</B>. From time to time, Stockholder shall execute and deliver, or cause to
be executed and delivered, such additional instruments, and shall take such further actions, as Parent may reasonably request for the purpose of carrying out and furthering the intent of this Agreement. Stockholder hereby gives any consents or
waivers that are reasonably required for the consummation of the Merger on the terms and conditions set forth in the Merger Agreement under the terms of any agreement or instrument to which Stockholder is a party or subject or in respect of any
rights Stockholder may have. Stockholder further consents to the Company placing a stop transfer order on the Shares with its transfer agent(s) in accordance with this Agreement until the Expiration 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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.2 Notices</B>. Any notice or other communication required or permitted
to be delivered to either party under this Agreement shall be in writing and shall be deemed properly delivered, given and received when received at the address or facsimile telephone number set forth beneath the name of such party below (or at such
other address or facsimile telephone number as such party shall have specified in a written notice given to the other party): </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2">if to Stockholder: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">at the address set forth on the signature page hereof; and </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2">if to Parent: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Nektar Therapeutics </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2">150 Industrial Road </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">San Carlos, CA 94070 </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Attn: Nevan Elam </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2">Fax:&nbsp;&nbsp;&nbsp;(650) 631-3150 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">with a copy
(which shall not constitute notice) to: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2">Wilson Sonsini Goodrich &amp; Rosati </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Professional Corporation </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">650 Page Mill Road </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2">Palo Alto, CA 94304-1050 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Attention: Martin W. Korman </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:8%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Facsimile:&nbsp;&nbsp;(650) 493-6811 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.3 Severability</B>. Any term or provision of this Agreement that is invalid or unenforceable in any situation in any jurisdiction shall not affect
the validity or enforceability of the remaining terms and provisions hereof or the validity or enforceability of the offending term </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 FACE="Times New Roman" SIZE="2">5. </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">or provision in any other situation or in any other jurisdiction. If the final judgment of a court of competent
jurisdiction declares that any term or provision hereof is invalid or unenforceable, the parties hereto agree that the court making such determination shall have the power to limit the term or provision, to delete specific words or phrases, or to
replace any invalid or unenforceable term or provision with a term or provision that is valid and enforceable and that comes closest to expressing the intention of the invalid or unenforceable term or provision, and this Agreement shall be
enforceable as so modified. In the event such court does not exercise the power granted to it in the prior sentence, the parties hereto agree to replace such invalid or unenforceable term or provision with a valid and enforceable term or provision
that will achieve, to the extent possible, the economic, business and other purposes of such invalid or unenforceable term. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.4 Entire Agreement</B>. This Agreement, the Proxy and any other documents delivered by the parties in connection herewith constitute the entire
agreement between the parties with respect to the subject matter hereof and thereof and supersede all prior agreements and understandings between the parties with respect thereto. No addition to or modification of any provision of this Agreement
shall be binding upon either party unless made in writing and signed by both parties. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2"><B>6.5 Termination</B>. This Agreement and the Proxy delivered in connection herewith shall terminate and shall have no further force or effect as of the Expiration 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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.6 Assignment; Binding Effect</B>. Except as provided herein, neither
this Agreement nor any of the interests or obligations hereunder may be assigned or delegated by Stockholder, and any attempted or purported assignment or delegation of any of such interests or obligations shall be void. Subject to the preceding
sentence, this Agreement shall be binding upon Stockholder and Stockholder&#146;s successors and assigns, and shall inure to the benefit of Parent and its successors and assigns. Without limiting any of the restrictions set forth in Section 2 or
elsewhere in this Agreement, this Agreement shall be binding upon any Person to whom any Subject Securities are transferred. Nothing in this Agreement is intended to confer on any Person (other than Parent and its successors and assigns) any rights
or remedies of any nature.<B></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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.7 Specific Performance.
</B>The parties agree that irreparable damage would occur in the event that any of the provisions of this Agreement were not performed in accordance with its specific terms or were otherwise breached. Stockholder agrees that, in the event of any
breach by Stockholder of any covenant or obligation contained in this Agreement, Parent shall be entitled to seek: (a) a decree or order of specific performance to enforce the observance and performance of such covenant or obligation; and (b) an
injunction restraining such breach. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.8 Governing Law;
Jurisdiction; Waiver of Jury Trial.</B> </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(a) </B>This
Agreement shall be governed by, and construed in accordance with, the laws of the State of Delaware, regardless of the laws that might otherwise govern under applicable principles of conflicts of laws thereof. Each of the parties hereto: (i)
consents to submit itself to the personal jurisdiction of the Court of Chancery of the State of Delaware, in the event any dispute arises out of this Agreement; (ii) agrees that it will not attempt to deny or defeat such personal jurisdiction by
motion or other request for leave from any such court; and (iii) agrees that it will not bring any action relating to this Agreement in any court other than the Court of Chancery of the State of Delaware. </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 FACE="Times New Roman" SIZE="2">6. </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(b) </B>STOCKHOLDER IRREVOCABLY WAIVES THE RIGHT TO A JURY TRIAL IN CONNECTION WITH ANY LEGAL
PROCEEDING RELATING TO THIS AGREEMENT OR THE ENFORCEMENT OF ANY PROVISION OF THIS 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; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2"><B>6.9 Counterparts. </B>This Agreement may be executed in separate counterparts, each of which when so executed and delivered shall be an original, but all such counterparts shall together constitute one and the same
instrument. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.10 Captions</B>. The captions contained in
this Agreement are for convenience of reference only, shall not be deemed to be a part of this Agreement and shall not be referred to in connection with the construction or interpretation of this 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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.11 Waiver</B>. No failure on the part of Parent to exercise any power,
right, privilege or remedy under this Agreement, and no delay on the part of Parent in exercising any power, right, privilege or remedy under this Agreement, shall operate as a waiver of such power, right, privilege or remedy; and no single or
partial exercise of any such power, right, privilege or remedy shall preclude any other or further exercise thereof or of any other power, right, privilege or remedy. Parent shall not be deemed to have waived any claim available to Parent arising
out of this Agreement, or any power, right, privilege or remedy of Parent under this Agreement, unless the waiver of such claim, power, right, privilege or remedy is expressly set forth in a written instrument duly executed and delivered on behalf
of Parent; and any such waiver shall not be applicable or have any effect except in the specific instance in which it is given.<B></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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>6.12 Construction. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(a) </B>For purposes of this Agreement, whenever the context requires: the singular number shall include the plural, and vice versa; the masculine
gender shall include the feminine and neuter genders; the feminine gender shall include the masculine and neuter genders; and the neuter gender shall include masculine and feminine genders. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(b) </B>The parties agree that any rule of construction to the effect that
ambiguities are to be resolved against the drafting party shall not be applied in the construction or interpretation of this 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; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(c) </B>As used in this Agreement, the words &#147;include&#148; and &#147;including,&#148; and variations thereof, shall not be deemed to be terms of
limitation, but rather shall be deemed to be followed by the words &#147;without limitation.&#148; </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(d) </B>Except as otherwise indicated, all references in this Agreement to &#147;Sections&#148; and &#147;Exhibits&#148; are intended to refer to
Sections of this Agreement and Exhibits to this 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 FACE="Times New Roman"
SIZE="2"><I>[Remainder of page intentionally left blank.] </I></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 FACE="Times New Roman" SIZE="2">7. </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>I<SMALL>N</SMALL> W<SMALL>ITNESS</SMALL> W<SMALL>HEREOF</SMALL></B><SMALL></SMALL>, Parent and
Stockholder have caused this Agreement to be executed as of the date first written above. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0">

<TR>
<TD WIDTH="15%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="84%"></TD></TR>
<TR>
<TD VALIGN="bottom" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B><U>N<SMALL>EKTAR</SMALL> T<SMALL>HERAPEUTICS</SMALL></U></B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
FACE="Times New Roman" SIZE="2"><B>P<SMALL>ARENT</SMALL></B></FONT></P></TD></TR>
<TR>
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">By</FONT></P></TD></TR>

<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">Title</FONT></P></TD></TR>
<TR>
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2"><B>S<SMALL>TOCKHOLDER</SMALL></B></FONT></TD></TR>
<TR>
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">Signature</FONT></P></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Printed
Name</FONT></P></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Address:</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Facsimile:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
</TABLE></DIV> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="27%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD WIDTH="24%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD WIDTH="25%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD></TD></TR>
<TR>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Common Shares</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Held of Record</B></FONT></P><HR WIDTH="88" SIZE="1" NOSHADE COLOR="#000000"></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 FACE="Times New Roman" SIZE="1"><B>Preferred Shares</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Held of Record</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></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 FACE="Times New Roman" SIZE="1"><B>Options and Other</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Rights</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Additional</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="1"><B>Securities</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Beneficially</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Owned</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
</TABLE>



<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B><U>EXHIBIT A </U></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 FACE="Times New Roman" SIZE="2"><B><U>IRREVOCABLE PROXY TO VOTE STOCK OF AEROGEN, INC.. </U></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 FACE="Times New Roman" SIZE="2"><B>IRREVOCABLE PROXY </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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The undersigned stockholder (&#147;Stockholder&#148;) of Aerogen, Inc., a Delaware corporation (the &#147;Company&#148;), hereby irrevocably (to the
fullest extent permitted by law) appoints each of Chief Executive Officer and Senior Vice President of Corporate Operations of Nektar Therapeutics, a Delaware corporation (&#147;Parent&#148;), as the sole and exclusive attorneys and proxies of the
undersigned, with full power of substitution and resubstitution, to vote and exercise all voting and related rights (to the full extent that the undersigned is entitled to do so) with respect to all of the shares of capital stock of the Company that
now are or hereafter may be beneficially owned by the undersigned, and any and all other shares or securities of the Company issued or issuable in respect thereof on or after the date hereof (collectively, the &#147;Shares&#148;), in accordance with
the terms of this Proxy. The Shares beneficially owned by the undersigned stockholder of the Company as of the date of this Irrevocable Proxy are listed on the final page of this Irrevocable Proxy. Upon the undersigned&#146;s execution of this
Irrevocable Proxy, any and all prior proxies given by the undersigned with respect to the voting of any Shares on the matters referred to in the third full paragraph of this Irrevocable Proxy are hereby revoked and the undersigned agrees not to
grant any subsequent proxies with respect to such matters (other than in connection with Stockholder&#146;s compliance with Section 3(a) of the Voting Agreement (as defined below)) until after the Expiration Date (as defined in the Voting
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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">This Irrevocable Proxy is irrevocable (to the
fullest extent permitted by law), is coupled with an interest, and is granted in connection with the Voting Agreement, dated as of the date hereof, between Parent and the undersigned stockholder of the Company (the &#147;Voting Agreement&#148;) and
is granted in consideration of Parent entering into that certain Agreement and Plan of Merger such executed agreement, with such amendments and modifications thereto as are consented to by the Stockholder, (the &#147;Merger Agreement&#148;) by and
among Parent, Oski Acquisition Corporation, a Delaware corporation and an indirect wholly owned subsidiary of Parent (&#147;Merger Sub&#148;), and the Company, which Merger Agreement provides for the merger of Merger Sub with and into the Company
(the &#147;Merger&#148;). This Irrevocable Proxy will terminate at the Expiration Date. All capitalized terms not defined herein shall have the meaning set forth in the Voting 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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The attorneys and proxies named above, and each of them are hereby authorized and empowered by the undersigned, at any time
prior to the Expiration Date, to act as the undersigned&#146;s attorney and proxy to vote the Shares, and to exercise all voting rights of the undersigned with respect to the Shares (including, without limitation, the power to execute and deliver
written consents), at every annual, special, adjourned or postponed meeting of the stockholders of the Company and in every written consent in lieu of such meeting: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(a) </B>in favor of: (i) the adoption of the Merger Agreement; (ii) each of the other transactions contemplated by the
Merger Agreement; and (iii) any action in furtherance of any of the foregoing; </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 FACE="Times New Roman" SIZE="2">A-2 </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(b) </B>against the following actions (other than the Merger and the transactions contemplated by the
Merger Agreement): (i) any merger, consolidation or other business combination involving the Company or any subsidiary of the Company; (ii) any sale or other transfer of all or substantially all of the assets of the Company and its subsidiaries
taken as a whole; (iii) any sale, lease, license or transfer of any significant part of the assets of the Company or any subsidiary of the Company; (iv) any reorganization, recapitalization, dissolution, liquidation or winding up of the Company or
any subsidiary of the Company; or (v) any other action which is intended, or would reasonably be expected, to interfere with or delay in any material respect the Merger or any of the other transactions contemplated by the Merger Agreement or this
Agreement (including any action or agreement that would result in a breach of any representation, warranty, covenant, agreement or other obligation of the Company in the Merger Agreement); and </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:8%"><FONT FACE="Times New Roman" SIZE="2"><B>(c) </B>in favor of: (i) approving a Certificate of Amendment to the
Company&#146;s Certificate of Designations, Preferences and Rights of the Preferred Stock in the form of Exhibit B to the Voting Agreement; and (ii) any action in furtherance of the foregoing.<B></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; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The attorneys and proxies named above may not exercise this Irrevocable Proxy
on any other matter except as provided above. The undersigned stockholder may vote the Shares on all other matters. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">All authority herein conferred shall survive the death or incapacity of the undersigned and any obligation of the undersigned hereunder shall be binding
upon the successors and assigns of the undersigned. </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 FACE="Times New Roman"
SIZE="2"><I>[Remainder of page intentionally left blank.] </I></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 FACE="Times New Roman" SIZE="2">A-3 </FONT></P>


<p Style='page-break-before:always'>
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 <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">This Irrevocable Proxy is coupled with an interest as aforesaid and is irrevocable. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0">

<TR>
<TD WIDTH="15%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="84%"></TD></TR>
<TR>
<TD VALIGN="bottom" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2"><B>S<SMALL>TOCKHOLDER</SMALL></B></FONT></TD></TR>
<TR>
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">Signature</FONT></P></TD></TR>
<TR>
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Printed
Name</FONT></P></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Address:</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Facsimile:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
</TABLE></DIV> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="27%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD WIDTH="24%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD WIDTH="25%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD></TD></TR>
<TR>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Common Shares</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Held of Record</B></FONT></P><HR WIDTH="88" SIZE="1" NOSHADE COLOR="#000000"></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 FACE="Times New Roman" SIZE="1"><B>Preferred Shares</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Held of Record</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></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 FACE="Times New Roman" SIZE="1"><B>Options and Other</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Rights</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Additional</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="1"><B>Securities</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Beneficially</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Owned</B></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
</TABLE>


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