FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person *   Musket David B 2. Date of Event Requiring Statement (Month/Day/Year) 03/03/2005 3. Issuer Name and Ticker or Trading Symbol AEROGEN INC [AEGN] (Last) (First) (Middle) 125 CAMBRIDGEPARK DRIVE,  4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) CAMBRIDGE, MA 02140 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 120,942 D   Common Stock 539,466 I See Footnote (1) Common Stock 455,480 I See Footnote (2) Common Stock 83,986 I See Footnote (3) Common Stock 73,564 I See Footnote (4) Common Stock 73,564 I See Footnote (5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Musket David B 125 CAMBRIDGEPARK DRIVE CAMBRIDGE, MA 02140	Â	  X	Â	Â
KUROKAWA BARRY C/O PROMED PARTNERS, L.P. 125 CAMBRIDGEPARK DRIVE CAMBRIDGE, MA 02140	Â	Â	Â	Joint Filer
PROMED ASSET MANAGEMENT, LLC 125 CAMBRIDGEPARK DRIVE CAMBRIDGE, MA 02140	Â	Â	Â	Joint Filer
PROMED PARTNERS L P 125 CAMBRIDGEPARK DR CAMBRIDGE, MA 02104	Â	Â	Â	Joint Filer
PROMED PARTNERS II LP 125 CAMBRIDGEPARK DR CAMBRIDGE, MA 02104	Â	Â	Â	Joint Filer
PROMED MANAGEMENT INC 125 CAMBRIDGEPARK DR CAMBRIDGE, MA 02104	Â	Â	Â	Joint Filer
PROMED OFFSHORE FUND, LTD 125 CAMBRIDGEPARK DRIVE CAMBRIDGE, MA 02140	Â	Â	Â	Joint Filer
PROMED OFFSHORE FUND II, LTD 125 CAMBRIDGEPARK DRIVE CAMBRIDGE, MA 02140	Â	Â	Â	Joint Filer

Signatures

David B. Musket		05/19/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	These securities may be deemed to be beneficially owned by ProMed Asset Management, L.L.C. ("ProMed Asset Management"), the general partner of ProMed Partners, L.P. ("ProMed I") and ProMed Partners II, L.P. ("ProMed II"), and may also be deemed to be beneficially owned by David B. Musket and Barry Kurokawa, the managing members of ProMed Asset Management. These securities are owned by and are held in the accounts of ProMed I and ProMed II. Mr. Kurokawa also directly owns 1,533 shares of the Issuer. 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.
(2)	These securities are owned by and are held in the account of ProMed I.
(3)	These securities are owned by and are held in the account of ProMed II.
(4)	These securities may be deemed to be beneficially owned by ProMed Management, Inc. ("ProMed Management"), the investment manager of ProMed Offshore Fund, Ltd. ("ProMed Offshore I"). ProMed Management is controlled by David B. Musket and Barry Kurokawa. These securities are owned by and are held in the account of ProMed Offshore I. 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.
(5)	These securities are owned by and are held in the account of ProMed Offshore I.

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