<SUBMISSION>
<ACCESSION-NUMBER>0000950005-02-000129
<TYPE>SC 13G/A
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20020211
<GROUP-MEMBERS>ALAN W. CRITES ("CRITES")
<GROUP-MEMBERS>ARNOLD L. ORONSKY ("ORONSKY")
<GROUP-MEMBERS>GILBERT H. KLIMAN ("KLIMAN")
<GROUP-MEMBERS>HARVEY B. CASH ("CASH")
<GROUP-MEMBERS>INTERWEST INVESTORS VI, LP ("II VI")
<GROUP-MEMBERS>INTERWEST MANAGEMENT PARTNERS VI, LLC ("IMP VI")
<GROUP-MEMBERS>INTERWEST PARTNERS VI, LP ("IWP VI")
<GROUP-MEMBERS>PHILIP T. GIANOS ("GIANOS")
<GROUP-MEMBERS>ROBERT R. MOMSEN ("MOMSEN")
<GROUP-MEMBERS>W. SCOTT HEDRICK ("HEDRICK")
<GROUP-MEMBERS>W. STEPHEN HOLMES ("HOLMES")
<FILED-BY>
<COMPANY-DATA>
<CONFORMED-NAME>INTERWEST PARTNERS VI L P
<CIK>0001019182
<IRS-NUMBER>943247382
<STATE-OF-INCORPORATION>NV
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC 13G/A
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>3000 SAND HILL ROAD
<STREET2>BUILDING 3 SUITE 255
<CITY>MENLO PARK
<STATE>CA
<ZIP>94025
<PHONE>6508548585
</BUSINESS-ADDRESS>
</FILED-BY>
<SUBJECT-COMPANY>
<COMPANY-DATA>
<CONFORMED-NAME>AEROGEN INC
<CIK>0001039160
<ASSIGNED-SIC>3841
<IRS-NUMBER>330488580
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC 13G/A
<ACT>34
<FILE-NUMBER>005-60561
<FILM-NUMBER>02533351
</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>
</SUBJECT-COMPANY>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>p14914_13g.txt
<DESCRIPTION>AMENDMENT NO.1
<TEXT>



                                  United States
                       Securities and Exchange Commission
                             WASHINGTON, D.C. 20549


                                  Schedule 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                                (Amendment no. 1)

                                  AeroGen, Inc.
              --------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
           ---------------------------------------------------------
                         (Title of Class of Securities)

                                   007779 10 1
           --------------------------------------------------------
                                 (CUSIP Number)

                                   12-31-2001
            -------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)



Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

            [ ]      Rule 13d-1(b)

            [ ]      Rule 13d-1(c)

            [X]      Rule 13d-1(d)




*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

                                   Page 1 of 16 pages


<PAGE>

CUSIP No. 007779 10 1                   13G                         Page 2 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    InterWest Partners VI, LP
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    California
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       1,227,063
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          0
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             1,227,063
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       0
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,227,063
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.1%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 2 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                         Page 3 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    InterWest Investors VI, LP
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    California
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       37,486
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          0
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             37,486
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       0
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    37,486
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    0.2%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 3 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                         Page 4 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    InterWest Management Partners VI, LLC (the general partner of InterWest
           Partners VI, LP and InterWest Investors VI, LP)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    California
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       1,264,549
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          0
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             1,264,549
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       0
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 4 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                         Page 5 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Harvey B. Cash (a Managing Director of InterWest Management
                   Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 5 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                         Page 6 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Alan W. Crites (a Managing Director of InterWest Management
                   Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 6 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                         Page 7 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Philip T. Gianos (a Managing Director of InterWest Management
         Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 7 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                         Page 8 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    W. Scott Hedrick (a Managing Director of InterWest Management
                     Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 8 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                         Page 9 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    W. Stephen Holmes (a Managing Director of InterWest Management
                      Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 9 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                        Page 10 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Gilbert H. Kliman (a Venture Member of InterWest Management
                      Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 10 of 16 pages
<PAGE>


CUSIP No. 007779 10 1                   13G                        Page 11 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Robert R. Momsen (a Managing Director of InterWest Management
                     Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 11 of 16 pages
<PAGE>

CUSIP No. 007779 10 1                   13G                        Page 12 of 16
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Arnold L. Oronsky (a Managing Director of InterWest Management
                      Partners VI, LLC)
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3   SEC USE ONLY


--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       0
                  --------------------------------------------------------------
   NUMBER OF      6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          1,264,549
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             0
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       1,264,549
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    1,264,549
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.3%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT
                               Page 12 of 16 pages
<PAGE>


Item 1.

(a)      Name of Issuer:  AeroGen, Inc. ("Issuer")


(b)      Address of Issuer's Principal Executive Offices:

         1310 Orleans Drive
         Sunnyvale, CA 94089

Item 2.

(a)      Name of Person(s) Filing:

         InterWest Partners VI, LP ("IWP VI")
         InterWest Investors VI, LP ("II VI")
         InterWest Management Partners VI, LLC ("IMP VI")
         Harvey B. Cash ("Cash")
         Alan W. Crites ("Crites")
         Philip T. Gianos ("Gianos")
         W. Scott Hedrick ("Hedrick")
         W. Stephen Holmes ("Holmes")
         Gilbert H. Kliman ("Kliman")
         Robert R. Momsen ("Momsen")
         Arnold L. Oronsky ("Oronsky")

(b)      Address of Principal Business Office or, if none, Residence:

         3000 Sand Hill Road
         Building 3, Suite 255
         Menlo Park, CA 94025

(c)      Citizenship/Place of Organization:

         IWP VI:      California
         II VI:       California
         IMP VI:      California
         Cash:        United States
         Crites:      United States
         Gianos:      United States
         Hedrick:     United States
         Holmes:      United States
         Kliman:      United States
         Momsen:      United States
         Oronsky:     United States


(d)      Title of Class of Securities:  Common Stock

(e)      CUSIP Number:     007779 10 1

Item 3.        Not applicable.

                               Page 13 of 16 pages
<PAGE>


Item 4.        Ownership.

================================================================================
                                                                All
                                                               Other
                       IWP VI       II VI        IMP VI     Individuals
                                                                 *
------- ------------- ---------- ------------ ------------- -------------
(a)     Beneficial
        Ownership     1,227,063       37,486     1,264,549     1,264,549
------- ------------- ---------- ------------ ------------- -------------
(b)     Percentage
        of Class           6.1%         0.2%          6.3%          6.3%
------- ------------- ---------- ------------ ------------- -------------
(c)     Sole Voting
        Power         1,227,063       37,486     1,264,549             0
------- ------------- ---------- ------------ ------------- -------------
        Shared
        Voting Power
                              0            0             0     1,264,549
------- ------------- ---------- ------------ ------------- -------------
        Sole
        Dispositive
        Power         1,227,063       37,486     1,264,549             0
------- ------------- ---------- ------------ ------------- -------------
        Shared
        Dispositive
        Power                 0            0             0     1,264,549
================================================================================

*Individuals  included in this column are Cash,  Crites,  Gianos,  Hedrick,  and
Holmes,  Momsen and Oronsky,  all of whom are Managing Directors of IMP VI. Also
included in this column is Kliman who is a Venture Member of IMP VI.

Item 5.        Ownership of Five Percent or Less of a Class

Not applicable.

Item 6.        Ownership of More than Five Percent on Behalf of Another Person

Under certain  circumstances  set forth in the partnership  agreement of IMP VI,
the general  partners and/or limited partners of such partnership have the right
to receive dividends from, or the proceeds from the sale of, the Common Stock of
Issuer beneficially owned by such Partnership.

Item 7.        Identification   and   Classification  of  the  Subsidiary  Which
               Acquired the  Security  Being  Reported on By the Parent  Holding
               Company.

Not applicable.

Item 8.        Identification and Classification of Members of the Group

No   reporting   person  is  a  member  of  a  group  as   defined   in  section
240.13d-1(b)(1)(iii)(H) of the Act.

Item 9.        Notice of Dissolution of Group

Not applicable.

Item 10.       Certification

Not applicable

EXHIBITS

A.    Joint Filing Statement

                               Page 14 of 16 pages

<PAGE>


                                    Signature

After  reasonable  inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

Date:    February ____, 2002


INTERWEST PARTNERS VI, LP

By:    InterWest Management Partners VI, LLC     -------------------------------
                                                 Harvey B. Cash
       By: ---------------------------------
           Managing Director                     -------------------------------
                                                 Alan W. Crites
INTERWEST INVESTORS VI, LP
                                                 -------------------------------
By:    InterWest Management Partners VI, LLC     Philip T. Gianos

       By: ---------------------------------     -------------------------------
           Managing Director                     W. Scott Hedrick

INTERWEST MANAGEMENT PARTNERS VI, LLC            -------------------------------
                                                 W. Stephen Holmes
By:    -------------------------------------
       Managing Director                         -------------------------------
                                                 Gilbert H. Kliman

                                                 -------------------------------
                                                 Robert R. Momsen

                                                 -------------------------------
                                                 Arnold L. Oronsky



                               Page 15 of 16 pages
<PAGE>

                                    EXHIBIT A

We, the undersigned, hereby express our agreement that the attached Schedule 13G
is filed on behalf of each of us.

Date:    February ____, 2002


INTERWEST PARTNERS VI, LP

By:    InterWest Management Partners VI, LLC     -------------------------------
                                                 Harvey B. Cash
       By: ---------------------------------
           Managing Director                     -------------------------------
                                                 Alan W. Crites
INTERWEST INVESTORS VI, LP
                                                 -------------------------------
By:    InterWest Management Partners VI, LLC     Philip T. Gianos

       By: ---------------------------------     -------------------------------
           Managing Director                     W. Scott Hedrick

INTERWEST MANAGEMENT PARTNERS VI, LLC            -------------------------------
                                                 W. Stephen Holmes
By:    -------------------------------------
       Managing Director                         -------------------------------
                                                 Gilbert H. Kliman

                                                 -------------------------------
                                                 Robert R. Momsen

                                                 -------------------------------
                                                 Arnold L. Oronsky



                               Page 16 of 16 pages



</TEXT>
</DOCUMENT>
</SUBMISSION>
