<SUBMISSION>
<ACCESSION-NUMBER>0001169232-05-003170
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>2
<PERIOD>20050427
<FILING-DATE>20050615
<DATE-OF-FILING-DATE-CHANGE>20050615
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>AEROGEN INC
<CIK>0001039160
<ASSIGNED-SIC>3841
<IRS-NUMBER>330488580
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<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>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PROMED PARTNERS II LP
<CIK>0001144358
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896359
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
<PHONE>6174418800
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PROMED PARTNERS L P
<CIK>0001011552
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896360
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DR
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02104
<PHONE>6174418800
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PROMED ASSET MANAGEMENT, LLC
<CIK>0001328778
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896361
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
<PHONE>617-441-8800
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>KUROKAWA BARRY
<CIK>0001329753
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896362
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>617-441-8800
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O PROMED PARTNERS, L.P.
<STREET2>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Musket David B
<CIK>0001310611
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896363
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>(650) 614-4100
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O CONOR MEDSYSTEMS, INC.
<STREET2>1003 HAMILTON COURT
<CITY>MENLO PARK
<STATE>CA
<ZIP>94025
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PROMED OFFSHORE FUND II, LTD
<CIK>0001328780
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896364
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
<PHONE>617-441-8800
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PROMED MANAGEMENT INC
<CIK>0001101088
<STATE-OF-INCORPORATION>MA
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896366
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O MUSKET RESEARCH ASSOCIATES INC
<STREET2>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
</BUSINESS-ADDRESS>
<FORMER-NAME>
<FORMER-CONFORMED-NAME>PROMED MANAGEMENT L L C
<DATE-CHANGED>19991215
</FORMER-NAME>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PROMED OFFSHORE FUND, LTD
<CIK>0001328779
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-31913
<FILM-NUMBER>05896365
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
<PHONE>617-441-8800
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 CAMBRIDGEPARK DRIVE
<CITY>CAMBRIDGE
<STATE>MA
<ZIP>02140
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>d05-64248_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-04-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001039160</issuerCik>
        <issuerName>AEROGEN INC</issuerName>
        <issuerTradingSymbol>AEGN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001310611</rptOwnerCik>
            <rptOwnerName>Musket David B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>125 CAMBRIDGEPARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001329753</rptOwnerCik>
            <rptOwnerName>KUROKAWA BARRY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PROMED PARTNERS, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>125 CAMBRIDGEPARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Joint Filer</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001328778</rptOwnerCik>
            <rptOwnerName>PROMED ASSET MANAGEMENT, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>125 CAMBRIDGEPARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Joint Filer</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001011552</rptOwnerCik>
            <rptOwnerName>PROMED PARTNERS L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>125 CAMBRIDGEPARK DR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>125 CAMBRIDGEPARK DR</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02104</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Joint Filer</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001144358</rptOwnerCik>
            <rptOwnerName>PROMED PARTNERS II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>125 CAMBRIDGEPARK DR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02104</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Joint Filer</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001101088</rptOwnerCik>
            <rptOwnerName>PROMED MANAGEMENT INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>125 CAMBRIDGEPARK DR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02104</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Joint Filer</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001328779</rptOwnerCik>
            <rptOwnerName>PROMED OFFSHORE FUND, LTD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>125 CAMBRIDGEPARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Joint Filer</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001328780</rptOwnerCik>
            <rptOwnerName>PROMED OFFSHORE FUND II, LTD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>125 CAMBRIDGEPARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Joint Filer</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-04-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5700</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.9574</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>883601</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reported purchase of 25,000 shares of the Issuer was made on behalf of the account of ProMed Offshore II Fund, Ltd., a
private investment fund (which as of the date of this Form 4, owns 58,000 shares of the Issuer), the Investment Manager of
which is ProMed Management, Inc. (&quot;ProMed Management&quot;). ProMed Management is controlled by David B. Musket and Barry
Kurokawa. The remainder of the reported amount of securities beneficially owned following the reported transaction may be
deemed to be beneficially owned as follows: (A) 455,480 shares of the Issuer owned by and held in the account of ProMed
Partners, L.P., whose general partner is ProMed Asset Management, L.L.C. (&quot;ProMed Asset Management&quot;), which is controlled by
David B. Musket and Barry Kurokawa; See foot note 2.</footnote>
        <footnote id="F2">(B) 83,986 shares of the Issuer owned by and held in the account of ProMed Partners II, L.P., whose general
partner is also ProMed Asset Management; (C) 73,564 shares of the Issuer owned by and held in the account of ProMed Offshore
Fund, Ltd., whose investment manager is ProMed Management; (D) 120,942 shares of the Issuer owned directly by David B.
Musket; and (E) 1,533 shares of the Issuer owned directly by Barry Kurokawa. Each Reporting Person disclaims beneficial
ownership of the reported securities except to the extent of his or its pecuniary interest therein, and this report shall
not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16
of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>David B. Musket</signatureName>
        <signatureDate>2005-05-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99
<SEQUENCE>2
<FILENAME>d64248_ex99.htm
<DESCRIPTION>JOINT FILING INFORMATION
<TEXT>
<HTML>
<HEAD>
<TITLE> </TITLE>
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<div style='width:600;'>

<!-- MARKER FORMAT-SHEET="Head Right-TNR" FSL="Workstation" -->
<P ALIGN=RIGHT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Exhibit 99 </FONT></P>


        <p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>&nbsp;&nbsp;<u><b><font size=2>Joint Filing Information</font></b></u></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Name: Barry Kurokawa</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="620" style=' border-collapse:collapse'>
      <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Address: </font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>125 Cambridgepark Drive</font></p> </td>

</tr>
     <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Cambridge, MA 02140</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Designated Filer: David B. Musket</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="450" style=' border-collapse:collapse'>
      <tr>
         <td width="307" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Issuer and Ticker Symbol:

Aerogen&nbsp;Inc.</font></p> </td>
         <td width="75" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font SIZE=2>AEGN</font></p> </td> </tr>
     <tr>
         <td width="307" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="109" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td> </tr>
     <tr>
         <td width="95" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Date of Event Requiring Filing:</font></p>

</td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>April 27, 2005</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="292" style=' border-collapse:collapse'>
      <tr >
         <td width="96" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;&nbsp;Signature:</font></p> </td>
         <td width="132" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Barry Kurokawa</font></p> </td>
         <td  width="64">
            <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></td> </tr>
     <tr >
         <td  width="96">
            <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></td>
         <td  colspan="2" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>By:  /s/Barry Kurokawa</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Date: May 19, 2005</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>
</p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>
<br>
<HR noshade align="center" width="100%" size="2">

<p style='page-break-before:always'></p>


<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;<u><b>Joint Filing
Information</b></u> </FONT></P>


<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Name: ProMed Asset Management, L.L.C.</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="600" style=' border-collapse:collapse'>
      <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Address: </font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>125 Cambridgepark Drive</font></p> </td>

</tr>
     <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Cambridge, MA 02140</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt; margin-left:0.75in;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Designated Filer: David B. Musket</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="400" style=' border-collapse:collapse'>
      <tr>
        <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Issuer and Ticker Symbol: Aerogen

Inc.</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font SIZE=2>AEGN</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;Date of Event Requiring Filing:</font></p>

</td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>April 27, 2005</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="364" style=' border-collapse:collapse'>
      <tr>
         <td width="96" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;&nbsp;Signature:</font></p> </td>
         <td width="268" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>ProMed Asset Management,

L.L.C.</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="196" style=' margin-left:1.0in;border-collapse:collapse'>
      <tr>
         <td width="196" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>By: /s/David B. Musket</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Date: May 19, 2005</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>
</p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>
<br>
<HR noshade align="center" width="100%" size="2">
<p style='page-break-before:always'></p>



<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>&nbsp;&nbsp;<u><b><font size=2>Joint Filing Information</font></b></u></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Name: ProMed Partners, L.P.</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="600" style=' border-collapse:collapse'>
      <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Address: </font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>125 Cambridgepark Drive</font></p> </td>

</tr>
     <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Cambridge, MA 02140</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Designated Filer: David B. Musket</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="400" style=' border-collapse:collapse'>
      <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Issuer and Ticker Symbol: Aerogen

Inc.</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font SIZE=2>AEGN</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Date of Event Requiring Filing:</font></p>

</td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>April 27, 2005</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="284" style=' border-collapse:collapse'>
      <tr>
         <td width="96" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;&nbsp;Signature:</font></p> </td>
         <td width="188" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>ProMed Partners, L.P.</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt; text-indent:1in;text-align:left;'><font size=2>By: ProMed Asset Management, L.L.C., its general

partner</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="204" style=' margin-left:1.0in;border-collapse:collapse'>
      <tr>
         <td width="204" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>By: /s/ David B. Musket</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Date: May 19, 2005</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>
</p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>
<br>
<HR noshade align="center" width="100%" size="2">
<p style='page-break-before:always'></p>



<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>&nbsp;&nbsp;<u><b><font size=2>Joint Filing Information</font></b></u></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Name: ProMed Partners II, L.P.</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="600" style=' border-collapse:collapse'>
      <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Address: </font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>125 Cambridgepark Drive</font></p> </td>

</tr>
     <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Cambridge, MA 02140</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Designated Filer: David B. Musket</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="400" style=' border-collapse:collapse'>
      <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Issuer and Ticker Symbol: Aerogen

Inc.</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font SIZE=2>AEGN</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Date of Event Requiring Filing:</font></p>

</td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>April 27, 2005</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="308" style=' border-collapse:collapse'>
      <tr>
         <td width="96" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;&nbsp;Signature:</font></p> </td>
         <td width="212" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>ProMed Partners II, L.P.</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt; text-indent:1in;text-align:left;'><font size=2>By: ProMed Asset Management, L.L.C., its general

partner</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="204" style=' margin-left:1.0in;border-collapse:collapse'>
      <tr>
         <td width="204" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>By: /s/ David B. Musket</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Date: May 19, 2005</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>
</p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>
<br>
<HR noshade align="center" width="100%" size="2">
<p style='page-break-before:always'></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>&nbsp;&nbsp;<u><b><font size=2>Joint Filing Information</font></b></u></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Name: ProMed Management, Inc.</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="600" style=' border-collapse:collapse'>
      <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Address: </font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>125 Cambridgepark Drive</font></p> </td>

</tr>
     <tr>
         <td width="63" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="575" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Cambridge, MA 02140</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Designated Filer: David B. Musket</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="400" style=' border-collapse:collapse'>
      <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Issuer and Ticker Symbol: Aerogen

Inc.</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font SIZE=2>AEGN</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;Date of Event Requiring Filing:</font></p>

</td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>April 27, 2005</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="300" style=' border-collapse:collapse'>
      <tr>
         <td width="96" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;&nbsp;Signature:</font></p> </td>
         <td width="204" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>ProMed Management, Inc.</font></p> </td>

</tr>
     <tr >
         <td  width="96">
            <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></td>
         <td width="204" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>By: /s/ David B. Musket</font></p> </td>

</tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Date: May 19, 2005</font></p>


<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>
</p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>
<br>
<HR noshade align="center" width="100%" size="2">
<p style='page-break-before:always'></p>
<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>&nbsp;&nbsp;<u><b><font size=2>Joint Filing Information</font></b></u></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Name: ProMed Offshore Fund, Ltd.</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Address: [TO BE INSERTED]</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Designated Filer: David B. Musket</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="400" style=' border-collapse:collapse'>
      <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Issuer and Ticker Symbol: Aerogen

Inc.</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font SIZE=2>AEGN</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1></font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1></font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Date of Event Requiring Filing:</font></p>
</td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>April 27, 2005</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="428" style=' border-collapse:collapse'>
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         <td width="96" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;&nbsp;Signature:</font></p> </td>
         <td width="228" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>ProMed Offshore Fund, Ltd.</font></p> </td>
         <td  width="104">
            <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></td> </tr>
     <tr >
         <td  width="96">
            <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></td>
         <td  colspan="2" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>By: /s/ David B. Musket, its

[Director]</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Date: May 19, 2005</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>
</p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>
<br>
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<p style='page-break-before:always'></p>


<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'>&nbsp;&nbsp;<u><b><font size=2>Joint Filing Information</font></b></u></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Name: ProMed Offshore Fund II, Ltd.</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Address: [TO BE INSERTED]</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;Designated Filer: David B. Musket</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="400" style=' border-collapse:collapse'>
      <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Issuer and Ticker Symbol: Aerogen

Inc.</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font SIZE=2>AEGN</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></p> </td> </tr>
     <tr>
         <td width="327" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>Date of Event Requiring Filing:</font></p>

</td>
         <td width="189" valign=top style='padding:0in 5.4pt 0in 5.4pt'>
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>April 27, 2005</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>


<table border="0" cellspacing=0 cellpadding=0 width="428" style=' border-collapse:collapse'>
      <tr >
         <td width="96" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>&nbsp;&nbsp;&nbsp;Signature:</font></p> </td>
         <td width="252" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>ProMed Offshore Fund II, Ltd.</font></p>

</td>
         <td  width="80">
            <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></td> </tr>
     <tr >
         <td  width="96">
            <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=1>&nbsp;</font></td>
         <td  colspan="2" valign=top >
             <p style='margin-left:0pt;text-indent:0pt;text-align:left;margin-top:0pt;margin-bottom:0pt'><font size=2>By: /s/ David B. Musket, its

[Director]</font></p> </td> </tr></table>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;&nbsp;&nbsp;Date: May 19, 2005</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>

<p style=' margin-bottom:0pt; margin-top:0pt;text-align:left;'><font size=2>&nbsp;</font></p>
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