<SUBMISSION>
<ACCESSION-NUMBER>0001104659-03-003001
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<PERIOD>20030224
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<ITEMS>7
<FILING-DATE>20030225
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>AEROGEN INC
<CIK>0001039160
<ASSIGNED-SIC>3841
<IRS-NUMBER>330488580
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
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<FORM-TYPE>8-K
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>03579615
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1310 CORONADO DR
<CITY>SANTA CLARA
<STATE>CA
<ZIP>95054
<PHONE>4085432400
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1310 ORLEANS DRIVE
<CITY>SUNNYVALE
<STATE>CA
<ZIP>94089
</MAIL-ADDRESS>
</FILER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>j7874_8k.htm
<DESCRIPTION>8-K
<TEXT>
<html>

<head>

<title>  </title>

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<body>

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<div style="border:none;border-top:double windowtext 9.0pt;padding:0in 0in 0in 0in;">

<p style="border:none;font-weight:bold;margin:0in 0in .0001pt;padding:0in;text-align:center;text-transform:uppercase;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:normal;text-transform:none;">&nbsp;</font></b></p>

</div>

<p style="font-weight:bold;margin:0in 0in .0001pt;text-align:center;text-transform:uppercase;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;text-transform:none;">SECURITIES AND EXCHANGE COMMISSION</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Washington, D. C.&#160;
20549</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">FORM 8-K</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">RELATING TO THE AMENDMENT OF
THE COMPANY&#146;S <br>
STOCKHOLDER RIGHTS PLAN</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">Pursuant to
Section&nbsp;13 or 15(d) of the<br>
Securities Exchange Act of 1934</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Date of Report:
February 25, 2003</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Date of earliest
event reported: February 24, 2003)</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="font-weight:bold;margin:0in 0in .0001pt;text-align:center;text-transform:uppercase;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;text-transform:none;">AEROGEN, INC.</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Exact name of
registrant as specified in its charter)</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<div align="center">

<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
 <tr>
  <td width="100%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Delaware</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(State or other
  jurisdiction of incorporation)</font></p>
  </td>
 </tr>
 <tr>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">0-31913</font></b></p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">33-0488580</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Commission File
  No.)</font></p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(IRS Employer
  Identification No.)</font></p>
  </td>
 </tr>
 <tr>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.0%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="49%" valign="top" style="padding:0in .7pt 0in .7pt;width:49.0%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">2071
  Stierlin Court<br>
  Mountain View, CA 94043</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(Address of
  principal executive offices and zip code)</font></p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:100.0%;">
  <p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="100%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:100.0%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Registrant&#146;s
  telephone number, including area code: <b><font style="font-weight:bold;">(650)&nbsp;864-7300</font></b></font></p>
  </td>
 </tr>
</table>

</div>

<div style="border:none;border-bottom:double windowtext 9.0pt;padding:0in 0in 0in 0in;">

<p align="center" style="border:none;margin:0in 0in .0001pt;padding:0in;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

</div>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>


<div align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">

<hr size="2" width="100%" noshade color="gray" align="left">

</font></div>

<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item
5.&#160; Other Events.</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">On February 24, 2003, Aerogen,
Inc. (the &#147;Company&#148;) entered into an amendment to the Rights Agreement,
dated as of June 5, 2001, between the Company and Mellon Investor Services LLC,
as rights agent (the &#147;Rights Agreement&#148;).&#160;
The Rights Agreement sets forth the terms and conditions of certain
rights to purchase shares of Series A Junior Participating Preferred Stock, par
value $0.001 per share, under the Company&#146;s Stockholder Rights Plan. The
amendment to the Rights Agreement provides for, among other things, an increase
in the percentage threshold of beneficial ownership required to become an
&#147;Acquiring Person&#148; (as defined in the Rights Agreement) from fifteen percent
(15%) or more to twenty percent (20%) or more, and excludes from the definition
of an &#147;Acquiring Person&#148; any person or entity who becomes the beneficial owner
of 20% or more of the common stock then outstanding as the result of the
acquisition of common stock directly from the Company.&#160; A copy of the amendment to the Rights
Agreement is attached hereto as Exhibit 99.1.</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item
7.&#160; Exhibits.</font></b></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
 <tr>
  <td width="11%" valign="top" style="padding:0in .7pt 0in .7pt;width:11.22%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>
  </td>
  <td width="2%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:2.18%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="86%" valign="top" style="padding:0in .7pt 0in .7pt;width:86.62%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Amendment to
  Rights Agreement, dated as of February 24, 2003, by and between Aerogen, Inc.
  and Mellon Investor Services LLC, as Rights Agent.</font></p>
  </td>
 </tr>
</table>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">1</font></p>


<div align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">

<hr size="2" width="100%" noshade color="gray" align="left">

</font></div>

<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">SIGNATURE</font></b></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned, hereunto duly authorized.</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
 <tr>
  <td width="55%" valign="top" style="padding:0in .7pt 0in .7pt;width:55.7%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="44%" valign="top" style="padding:0in .7pt 0in .7pt;width:44.3%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Aerogen</font></b><font style="text-transform:uppercase;">, <b><font style="font-weight:bold;">Inc.</font></b></font></p>
  </td>
 </tr>
 <tr>
  <td width="55%" valign="top" style="padding:0in .7pt 0in .7pt;width:55.7%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="44%" valign="top" style="padding:0in .7pt 0in .7pt;width:44.3%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="55%" valign="top" style="padding:0in .7pt 0in .7pt;width:55.7%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="44%" valign="top" style="padding:0in .7pt 0in .7pt;width:44.3%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="55%" valign="top" style="padding:0in .7pt 0in .7pt;width:55.7%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated:&#160; February 25, 2003</font></p>
  </td>
  <td width="44%" valign="top" style="border:none;border-bottom:solid windowtext .5pt;padding:0in .7pt 0in .7pt;width:44.3%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/&#160; Jane E. Shaw</font></p>
  </td>
 </tr>
 <tr>
  <td width="55%" valign="top" style="padding:0in .7pt 0in .7pt;width:55.7%;">
  <p align="left" style="font-size:1.0pt;font-variant:small-caps;font-weight:bold;margin:0in 0in .0001pt;page-break-after:avoid;text-align:left;">&nbsp;</p>
  </td>
  <td width="44%" valign="top" style="border:none;padding:0in .7pt 0in .7pt;width:44.3%;">
  <p align="left" style="font-variant:small-caps;font-weight:bold;margin:0in 0in .0001pt;page-break-after:avoid;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-variant:normal;font-weight:normal;">Jane E. Shaw, Ph.D.</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="55%" valign="top" style="padding:0in .7pt 0in .7pt;width:55.7%;">
  <p align="left" style="font-size:1.0pt;font-variant:small-caps;font-weight:bold;margin:0in 0in .0001pt;page-break-after:avoid;text-align:left;">&nbsp;</p>
  </td>
  <td width="44%" valign="top" style="padding:0in .7pt 0in .7pt;width:44.3%;">
  <p align="left" style="font-variant:small-caps;font-weight:bold;margin:0in 0in .0001pt;page-break-after:avoid;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-variant:normal;font-weight:normal;">Chairman and Chief Executive Officer</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="55%" valign="top" style="padding:0in .7pt 0in .7pt;width:55.7%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:0in;">&nbsp;</p>
  </td>
  <td width="44%" valign="top" style="padding:0in .7pt 0in .7pt;width:44.3%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:0in;"><i><font size="2" face="Times New Roman" style="font-size:10.0pt;font-style:italic;">(Principle Executive Officer)</font></i></p>
  </td>
 </tr>
</table>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">2</font></p>


<div align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">

<hr size="2" width="100%" noshade color="gray" align="left">

</font></div>

<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">INDEX TO
EXHIBITS</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
 <tr>
  <td width="12%" valign="top" style="padding:0in .7pt 0in .7pt;width:12.16%;">
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>
  </td>
  <td width="3%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:3.02%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="84%" valign="top" style="padding:0in .7pt 0in .7pt;width:84.82%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Amendment to
  Rights Agreement, dated as of February 24, 2003, by and between Aerogen, Inc.
  and Mellon Investor Services LLC, as Rights Agent.</font></p>
  </td>
 </tr>
</table>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">3</font></p>


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<p align="right" style="margin:0in 0in .0001pt;text-align:right;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">EXHIBIT
99.1</font></b></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">AMENDMENT
TO<br>
RIGHTS AGREEMENT</font></b></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">This <b><font style="font-weight:bold;text-transform:uppercase;">Amendment to Rights Agreement</font></b> (the &#147;Amendment&#148;) is
made as of February 24, 2003, by and between <b><font style="font-weight:bold;text-transform:uppercase;">Aerogen, Inc.</font></b>,
a Delaware corporation (the &#147;Company&#148;) and <b><font style="font-weight:bold;text-transform:uppercase;">Mellon Investor Services LLC</font></b>,
a New Jersey limited liability company, as Rights Agent (the &#147;Rights Agent&#148;).</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
the Company and the Rights Agent are parties to that certain Rights Agreement,
dated as of June 5, 2001 (the &#147;Rights Agreement&#148;);</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
pursuant to the Rights Agreement, each stockholder of record as of June 26,
2001 received certain rights to purchase shares of Series A Junior
Participating Preferred Stock, par value $0.001 per share, subject to the terms
and conditions therein (the &#147;Rights&#148;);</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
such Rights become exercisable in the event any Person or group of Persons
acquires, or announces a tender offer for, fifteen percent (15%) or more (the
&#147;Rights Threshold&#148;) of Aerogen&#146;s Common Shares then outstanding (each, an
&#147;Acquiring Person&#148;) pursuant to the terms and conditions of the Rights
Agreement, <i><font style="font-style:italic;">unless</font></i>
the Board of Directors of the Company has determined in good faith that such
Person or group of Persons has done so inadvertently and such Person or group
of Persons divests as promptly as practicable (as determined in good faith by
the Board of Directors) Beneficial Ownership of a sufficient number of Common
Shares so that such Person or group of Persons would no longer be an Acquiring
Person, in which case such Person or group of Persons shall not be deemed an
&#147;Acquiring Person&#148; for purposes of the Rights Agreement;</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
Mazama Capital Management, Inc. (&#147;Mazama&#148;) has reported that it beneficially
owned in the aggregate 19.17% of the Common Shares;</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
pursuant to the Rights Agreement, the Board of Directors has determined in good
faith that Mazama became an Acquiring Person inadvertently and that it shall
not be deemed an &#147;Acquiring Person&#148; for purposes of the Rights Agreement;</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
pursuant to Section 27 of the Rights Agreement, the Board of Directors of the
Company now wishes to amend the Rights Agreement to: (a) increase the Rights
Threshold from fifteen percent (15%) or more to twenty percent (20%) or more,
and (b) exclude from the definition of an &#147;Acquiring Person&#148; any Person who
becomes the Beneficial Owner of 20% or more of the Common Shares then
outstanding as the result of the acquisition of Common Shares directly from the
Company.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
pursuant to Section 28 of the Rights Agreement, which provides that the Board
of Directors shall have the exclusive power and authority to administer the
Rights Agreement and to exercise all rights and powers specifically granted to
the Board of Directors, or the Company, or as may be necessary or advisable in
the administration of the Rights</p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>


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<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Agreement, the Board of Directors
has determined that in light of such amendment to the Rights Agreement to
increase the Rights Threshold, no divestiture of Common Shares shall be
required of Mazama so long as Mazama Beneficially Owns less than twenty percent
(20%) of the outstanding Common Shares; and</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Whereas</font></b>,
the Board of Directors has approved this Amendment and authorized its
appropriate officers to execute and deliver the same to the Rights Agent.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Now,
Therefore</font></b>, in consideration of the foregoing and the mutual
agreements herein set forth, the parties hereby agree as follows:</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">1.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Capitalized Terms</font></b>.&#160; Capitalized but undefined terms used herein shall have the
meanings ascribed to them in the Rights Agreement.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">2.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Amendment to Rights Agreement</font></b>.&#160; The Rights Agreement shall be amended as
follows:</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt 1.5in;text-align:left;text-indent:-.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(a)</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>Section
1(a) shall be amended in its entirety to read as follows:</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt .5in;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&#147;<b><font style="font-weight:bold;">(a)</font></b></font><b><font size="1" style="font-size:3.0pt;font-weight:bold;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>&#147;Acquiring
Person&#148;</b> shall mean any Person (as such term is hereinafter defined) who or
which, together with all Affiliates and Associates (as such terms are hereinafter
defined) of such Person, shall be the Beneficial Owner (as such term is
hereinafter defined) of 20% or more of the Common Shares then outstanding.&#160; Notwithstanding the foregoing, (A) the term
Acquiring Person shall not include (i) the Company, (ii) any Subsidiary (as
such term is hereinafter defined) of the Company, (iii) any employee benefit or
compensation plan of the Company or any Subsidiary of the Company, (iv) any
entity holding Common Shares for or pursuant to the terms of any such employee benefit
or compensation plan of the Company or any Subsidiary of the Company, and (B)
no Person shall become an &#147;Acquiring Person&#148; either (x) as the result of an
acquisition of Common Shares by the Company which, by reducing the number of
shares outstanding, increases the proportionate number of shares beneficially
owned by such Person to 20% or more of the Common Shares then outstanding; <i><font style="font-style:italic;">provided,
however,</font></i> that if a Person shall become the Beneficial Owner of 20%
or more of the Common Shares then outstanding by reason of share purchases by
the Company and shall, following written notice from, or public disclosure by
the Company of such share purchases by the Company, become the Beneficial Owner
of any additional Common Shares without the prior consent of the Company and
shall then Beneficially Own more than 20% of the Common Shares then
outstanding, then such Person shall be deemed to be an &#147;Acquiring Person,&#148; (y)
as the result of the acquisition of Common Shares directly from the Company,
provided however that if a Person shall become the Beneficial Owner of 20% or
more of the Common Shares then outstanding by reason of share purchases
directly from the Company and shall, after that date, become Beneficial Owner
of any additional Common Shares without the prior written consent of the
Company and shall then Beneficially Own more than 20% of the Common Shares then
outstanding, then such Person shall be deemed to be an &#147;Acquiring Person,&#148; or
(z) if the Board of Directors determines in good faith that a Person who would
otherwise be an &#147;Acquiring Person,&#148; as</p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">2</font></p>


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<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p align="left" style="margin:0in 0in .0001pt .5in;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">defined pursuant
to the foregoing provisions of this paragraph (a), has become such
inadvertently, and such Person divests, as promptly as practicable (as determined
in good faith by the Board of Directors), following receipt of written notice
from the Company of such event, of Beneficial Ownership of a sufficient number
of Common Shares so that such Person would no longer be an Acquiring Person, as
defined pursuant to the foregoing provisions of this paragraph (a), then such
Person shall not be deemed to be an &#147;Acquiring Person&#148; for any purposes of this
Agreement; <i><font style="font-style:italic;">provided,
however,</font></i> that if such Person shall again become the Beneficial Owner
of 20% or more of the Common Shares then outstanding, such Person shall be
deemed an &#147;Acquiring Person,&#148; subject to the exceptions set forth in this
Section&nbsp;1(a).&#148;</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt 1.5in;text-align:left;text-indent:-.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(b)</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>Section
1(c)(iii) shall be amended in its entirety to read as follows:</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt .5in;text-align:left;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&#147;<b><font style="font-weight:bold;">(iii)</font></b></font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>which are
beneficially owned, directly or indirectly, by any other Person with which such
Person or any of such Person&#146;s Affiliates or Associates has any agreement,
arrangement or understanding (other than customary agreements with and between
underwriters and selling group members with respect to a bona fide public
offering of securities) for the purpose of acquiring, holding, voting (except
to the extent contemplated by the proviso to Section&nbsp;1(c)(ii)(B) hereof)
or disposing of any securities of the Company; <i><font style="font-style:italic;">provided, however,</font></i> an
agreement, arrangement or understanding for purposes of this
Section&nbsp;1(c)(iii) shall not be deemed to include actions, including any
agreement, arrangement or understanding, or statements by any member of the
Company&#146;s Board of Directors on the date of this Agreement, any subsequent
directors of the Company (the &#147;Successor Directors&#148;) who have been nominated by
a majority of directors who are directors as of the date of this Agreement or
who are Successor Directors, or by any Person of whom such a director is an
Affiliate or Associate, provided, however that this exception shall not apply
to a particular Person or Persons if and to the extent that such Person or
Persons, after the date of this Agreement, acquires Beneficial Ownership of
more than an additional 5% of the then outstanding Common Shares of the Company
unless (A) the shares are acquired directly from the Company or as part of an
employee benefit or compensation plan of the Company or a subsidiary of the
Company or (B) the Person establishes to the satisfaction of the directors of
the Company that it is acting on its own behalf and not in concert with any
other Person and will not, upon completion of any purchases, be the Beneficial
Owner of 20% or more of the outstanding Common Shares.</p>

<p style="margin:0in 0in .0001pt;text-align:justify;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="margin:0in 0in .0001pt .5in;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Notwithstanding
anything in this definition of Beneficial Ownership to the contrary, the
phrase, &#147;then outstanding,&#148; when used with reference to a Person&#146;s Beneficial
Ownership of securities of the Company, shall mean the number of such
securities then issued and outstanding together with the number of such
securities not then actually issued and outstanding which such Person would be
deemed to own beneficially hereunder.&#148;</font></p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt 1.5in;text-align:left;text-indent:-.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(c)</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>Section
23(b)(ii) shall be amended in its entirety to read as follows:</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt .5in;text-align:left;text-indent:1.0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&#147;<b><font style="font-weight:bold;">(ii)</font></b></font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>In
addition, the Board of Directors may, at its option, at any time after the time
a Person becomes an Acquiring Person and after the expiration of any</p>

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<p align="left" style="margin:0in 0in .0001pt .5in;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">period during which the holder of Rights may exercise
the rights under Section&nbsp;11(a)(ii) hereof but prior to any event described
in clause (x), (y) or (z) of the first sentence of Section&nbsp;13 hereof,
redeem all but not less than all of the then outstanding Rights at the
Redemption Price (x) in connection with any merger, consolidation or sale or
other transfer (in one transaction or in a series of related transactions) of
assets or earning power aggregating 50% or more of the assets or earning power
of the Company and its subsidiaries (taken as a whole) in which all holders of
Common Shares are treated alike and not involving (other than as a holder of
Common Shares being treated like all other such holders) an Interested
Stockholder or a Transaction Person or (y)(A) if and for so long as the
Acquiring Person is not thereafter the Beneficial Owner of 20% or more of the
then outstanding Common Shares, and (B) at the time of redemption no other
Persons are Acquiring Persons.&#148;</font></p>

<p style="margin:0in 0in .0001pt;text-align:justify;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">3.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Full Force and Effect</font></b>.&#160; All other terms of the Rights Agreement shall remain in full
force and effect.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Successors</font></b>.&#160;
All the covenants and provisions in this Amendment by or for the benefit
of the Company or the Rights Agent shall bind and inure to the benefit of their
respective successors and assigns hereunder.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">5.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Benefits of this Amendment</font></b>.&#160; Nothing herein this Amendment shall be
construed to give to any Person or corporation other than the Company, the
Rights Agent and the registered holders of the Right Certificates (and, prior
to the Distribution Date, the Common Shares) any legal or equitable right,
remedy or claim under this Amendment; but this Amendment shall be for the sole
and exclusive benefit of the Company, the Rights Agent and the registered
holders of the Right Certificates (and, prior to the Distribution Date, the
Common Shares).</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">6.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Severability</font></b>.&#160;
If any term, provision, covenant or restriction of this Amendment is
held by a court of competent jurisdiction or other authority to be invalid,
void or unenforceable, the remainder of the terms, provisions, covenants and
restrictions of this Amendment shall remain in full force and effect and shall
in no way be affected, impaired or invalidated.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">7.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Governing Law</font></b>.&#160;
This Amendment shall be deemed to be a contract made under the laws of
the State of Delaware and for all purposes shall be governed by and construed
in accordance with the laws of such State applicable to contracts to be made
and performed entirely within such State.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">8.</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><b><font style="font-weight:bold;text-transform:uppercase;">Counterparts</font></b>.&#160;
This Amendment may be executed in any number of counterparts and each of
such counterparts shall for all purposes be deemed to be an original, and all
such counterparts shall together constitute but one and the same instrument.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">[The remainder of this
page is intentionally left blank.]</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4</font></p>


<div align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">

<hr size="2" width="100%" noshade color="gray" align="left">

</font></div>

<font size="2" face="Times New Roman" style="font-size:10.0pt;">
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<p align="center" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:center;">&nbsp;</p>

<p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">In Witness
Whereof</font></b>, the parties hereto have caused this Amendment to be
duly executed and attested, all as of the date first written above.</p>

<p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Attest:</font></b></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Aerogen, Inc.</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="3%" valign="top" style="padding:0in .7pt 0in .7pt;width:3.86%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
  </td>
  <td width="41%" valign="top" style="border:none;border-bottom:solid windowtext .5pt;padding:0in .7pt 0in .7pt;width:41.32%;">
  <p align="left" style="margin:0in 0in .0001pt 20.0pt;text-align:left;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/&#160; Robert
  S. Breuil</font></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="3%" valign="top" style="padding:0in .7pt 0in .7pt;width:3.94%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
  </td>
  <td width="35%" valign="top" style="border:none;border-bottom:solid windowtext .5pt;padding:0in .7pt 0in .7pt;width:35.16%;">
  <p align="left" style="margin:0in 0in .0001pt 20.0pt;text-align:left;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/&#160; Jane E.
  Shaw</font></p>
  </td>
  <td width="7%" valign="top" style="padding:0in .7pt 0in .7pt;width:7.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Name: Robert S. Breuil</font></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Name:&#160; Jane E. Shaw</font></p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Title:&#160; Chief Financial Officer</font></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Title:&#160; President and Chief Executive Officer</font></p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Attest:</font></b></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><b><font size="2" face="Times New Roman"><font style="font-size:10.0pt;font-weight:bold;text-transform:uppercase;">Mellon Investor Services, LLC,<br>
  </font>as Rights Agent</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="font-size:10.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="3%" valign="top" style="padding:0in .7pt 0in .7pt;width:3.86%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
  </td>
  <td width="41%" valign="top" style="border:none;border-bottom:solid windowtext .5pt;padding:0in .7pt 0in .7pt;width:41.32%;">
  <p align="left" style="margin:0in 0in .0001pt 20.0pt;text-align:left;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/&#160; Kerri S.
  Jones</font></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="3%" valign="top" style="padding:0in .7pt 0in .7pt;width:3.94%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
  </td>
  <td width="35%" valign="top" style="border:none;border-bottom:solid windowtext .5pt;padding:0in .7pt 0in .7pt;width:35.16%;">
  <p align="left" style="margin:0in 0in .0001pt 20.0pt;text-align:left;text-indent:-10.0pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">/s/&#160; David
  Altschul</font></p>
  </td>
  <td width="7%" valign="top" style="padding:0in .7pt 0in .7pt;width:7.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Name:&#160; Kerri S. Jones</font></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Name:&#160; David Altschul</font></p>
  </td>
 </tr>
 <tr>
  <td width="45%" colspan="2" valign="top" style="padding:0in .7pt 0in .7pt;width:45.18%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Title:&#160; Assistant Vice President</font></p>
  </td>
  <td width="8%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:8.36%;">
  <p align="left" style="font-size:1.0pt;margin:0in 0in .0001pt;text-align:left;">&nbsp;</p>
  </td>
  <td width="46%" colspan="3" valign="top" style="padding:0in .7pt 0in .7pt;width:46.46%;">
  <p align="left" style="margin:0in 0in .0001pt;text-align:left;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Title:&#160; Client Service Manager</font></p>
  </td>
 </tr>
</table>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">5</font></p>


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