-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
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 jVT85gaHrJGR0pDmY2Mk5A==

<SEC-DOCUMENT>0000898432-05-000087.txt : 20050201
<SEC-HEADER>0000898432-05-000087.hdr.sgml : 20050201
<ACCEPTANCE-DATETIME>20050201183901
ACCESSION NUMBER:		0000898432-05-000087
CONFORMED SUBMISSION TYPE:	3/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050118
FILED AS OF DATE:		20050201
DATE AS OF CHANGE:		20050201

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AEROGEN INC
		CENTRAL INDEX KEY:			0001039160
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				330488580
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2071 STIERLIN COURT
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043
		BUSINESS PHONE:		650 864-7300

	MAIL ADDRESS:	
		STREET 1:		2071 STIERLIN COURT
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BIOTECHNOLOGY VALUE FUND L P
		CENTRAL INDEX KEY:			0000918923
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31913
		FILM NUMBER:		05567037

	BUSINESS ADDRESS:	
		STREET 1:		227 W MONROE STREET, SUITE 4800
		STREET 2:		227 W MONROE STREET, SUITE 4800
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		415-288-23

	MAIL ADDRESS:	
		STREET 1:		227 W MONROE STREET, SUITE 4800
		STREET 2:		227 W MONROE STREET, SUITE 4800
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BVF PARTNERS L P/IL
		CENTRAL INDEX KEY:			0001055947

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31913
		FILM NUMBER:		05567038

	BUSINESS ADDRESS:	
		STREET 1:		ONE SANSOME ST
		STREET 2:		39TH FL
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104
		BUSINESS PHONE:		3122637777

	MAIL ADDRESS:	
		STREET 1:		227 W MONROE
		STREET 2:		SUITE 4800
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BVF INC/IL
		CENTRAL INDEX KEY:			0001056807
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31913
		FILM NUMBER:		05567034

	BUSINESS ADDRESS:	
		STREET 1:		ONE SANSOME ST
		STREET 2:		39TH FLOOR
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104
		BUSINESS PHONE:		3122637777

	MAIL ADDRESS:	
		STREET 1:		C/O GROSVENOR CAPITAL MANAGEMENT
		STREET 2:		227 W MONROE ST, #4800
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BIOTECHNOLOGY VALUE FUND II LP
		CENTRAL INDEX KEY:			0001102444
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31913
		FILM NUMBER:		05567036

	BUSINESS ADDRESS:	
		STREET 1:		ONE SANSOME ST
		STREET 2:		39TH FL.
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104
		BUSINESS PHONE:		3122637777

	MAIL ADDRESS:	
		STREET 1:		C/O GROSVENOR CAPITAL MANAGEMENT
		STREET 2:		227 W. MONROE ST #4800
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BVF INVESTMENTS LLC
		CENTRAL INDEX KEY:			0001132245
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31913
		FILM NUMBER:		05567035

	BUSINESS ADDRESS:	
		STREET 1:		ONE SANSOME ST. 39TH FL
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104
		BUSINESS PHONE:		3127392123

	MAIL ADDRESS:	
		STREET 1:		C/O GROSVENOR CAPITAL MANAGEMENT LP
		STREET 2:		227 W. MONROE ST. #4800
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
</SEC-HEADER>
<DOCUMENT>
<TYPE>3/A
<SEQUENCE>1
<FILENAME>form3a_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2005-01-18</periodOfReport>

    <dateOfOriginalSubmission>2005-01-28</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001055947</rptOwnerCik>
            <rptOwnerName>BVF PARTNERS L P/IL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>227 WEST MONROE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 4800</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Indirect Beneficial Owner</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000918923</rptOwnerCik>
            <rptOwnerName>BIOTECHNOLOGY VALUE FUND L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>227 WEST MONROE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 4800</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnote (1)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001102444</rptOwnerCik>
            <rptOwnerName>BIOTECHNOLOGY VALUE FUND II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>227 WEST MONROE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 4800</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnote (1)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001132245</rptOwnerCik>
            <rptOwnerName>BVF INVESTMENTS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>227 WEST MONROE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 4800</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnote (1)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001056807</rptOwnerCik>
            <rptOwnerName>BVF INC/IL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE SANSOME ST</rptOwnerStreet1>
            <rptOwnerStreet2>31ST FLOOR</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94104</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Warrant No. 86</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-24</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-05-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>500000</value>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Warrant No. 88</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-24</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-03-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>316663</value>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Warrant No. 89</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-24</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-03-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25014</value>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Warrant No. 90</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-24</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-05-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1400</value>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Warrant No. 91</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-24</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-03-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>339600</value>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Warrant No. 92</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-24</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-05-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>400650</value>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of Common Stock, par value $0.001 per share, underlying the Warrants reported in this response are directly
beneficially owned by Biotechnology Value Fund, L.P., a Delaware limited partnership (&quot;BVF, L.P.&quot;) (500,000 shares);
Biotechnology Value Fund II, L.P., a Delaware limited partnership (&quot;BVF2, L.P.&quot;) (316,663 shares); BVF Investments, L.L.C., a
Delaware limited liability company (&quot;Investments&quot;) (766,664 shares); and indirectly beneficially owned by BVF Partners L.P.,
a
Delaware limited partnership (&quot;Partners&quot;), and by its general partner (&quot;GP&quot;) BVF Inc., a Delaware corporation (&quot;BVF Inc.&quot;),
which is also an investment advisor to Partners. Partners is the general partner of BVF, L.P. and BVF2, L.P., and is the
manager of Investments.</footnote>
        <footnote id="F2">Pursuant to the operating agreement of Investments, Partners is authorized, among other things, to invest the funds of Ziff
Asset Management, L.P., the majority member of Investments, in the equity securities described herein as being beneficially
owned by Investments. Mark N. Lampert is the sole shareholder and sole director of BVF Inc., and is an officer of BVF Inc.
This joint filing on Form 3 shall not be deemed an admission that Mark N. Lampert is, for purposes of Section 16 of the
Securities Exchange Act of 1934, as amended, or otherwise, the beneficial owner of any equity securities covered by this
joint filing. Mr. Lampert disclaims beneficial ownership of shares reported in this response, except to the extent that he
has a pecuniary interest therein.</footnote>
        <footnote id="F3">Shares are directly beneficially owned by BVF, L.P.</footnote>
        <footnote id="F4">Shares are directly beneficially owned by BVF2, L.P.</footnote>
        <footnote id="F5">Shares are directly beneficially owned by Investments.</footnote>
        <footnote id="F6">The Warrants contain a cashless exercise provision.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>BVF Partners, L.P., By: BVF Inc., its GP, By: /s/ Mark N. Lampert, President</signatureName>
        <signatureDate>2005-02-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>BIOTECHNOLOGY VALUE FUND, L.P., By: BVF Partners L.P., its GP, By: BVF Inc., its GP, By: /s/ Mark N. Lampert, President</signatureName>
        <signatureDate>2005-02-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>BIOTECHNOLOGY VALUE FUND II, L.P., By: BVF Partners L.P., its GP, By: BVF Inc., its GP, By: /s/ Mark N. Lampert, President</signatureName>
        <signatureDate>2005-02-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>BVF INVESTMENTS, L.L.C., By: BVF Partners L.P., its Manager, By: BVF Inc., its GP, By: /s/ Mark N. Lampert, President</signatureName>
        <signatureDate>2005-02-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>BVF Inc., By: /s/ Mark N. Lampert, President</signatureName>
        <signatureDate>2005-02-01</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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