United States Securities and Exchange Commission WASHINGTON, D.C. 20549 Schedule 13G (Amendment No. _8_)* UNDER THE SECURITIES EXCHANGE ACT OF 1934 RIGEL PHARMACEUTICALS, INC. ------------------------------------------------------ (Name of Issuer) Common Stock ------------------------------------------------------ (Title of Class of Securities) 766559108 ------------------------------------------------------ (CUSIP Number) August 20, 2004 -------------------------------------------------------------------------------- (Date of Event That Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: |_| Rule 13d-1(b) |X| Rule 13d-1(c) |_| 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). CUSIP No. 766559108 Page 2 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta Partners ------------------------------------------------------------------------------------------------------------------- (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 ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & Footnote 1 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & Footnote 1 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 1 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person IA ------------------------------------------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!Footnote 1: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 3 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta Partners II, Inc. ------------------------------------------------------------------------------------------------------------------- (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 ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned -------------------------------------------------------------- By Each Reporting (6) Shared Voting Power 1,097,880 Person With Please see Attachment A and Footnote 2 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A and Footnote 2 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 2 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person IA ------------------------------------------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!Footnote 2: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 4 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta California Partners, L. P. ------------------------------------------------------------------------------------------------------------------- (2) Check The Appropriate Box If A Member Of A Group (a) (b) X ------------------------------------------------------------------------------------------------------------------- (3) SEC Use Only ------------------------------------------------------------------------------------------------------------------- (4) Citizenship or Place of Organization Delaware ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & Footnote 3 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & Footnote 3 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 3 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person PN -------------------------------------------------------------------------------------------------------------------Footnote 3: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 5 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta California Management Partners, L. P. ------------------------------------------------------------------------------------------------------------------- (2) Check The Appropriate Box If A Member Of A Group (a) (b) X ------------------------------------------------------------------------------------------------------------------- (3) SEC Use Only ------------------------------------------------------------------------------------------------------------------- (4) Citizenship or Place of Organization Delaware ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & Footnote 4 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & Footnote 4 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 4 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person PN -------------------------------------------------------------------------------------------------------------------Footnote 4: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 6 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta Embarcadero Partners, 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 California ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & footnote 5 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & footnote 5 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 5 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person CO -------------------------------------------------------------------------------------------------------------------Footnote 5: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 7 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta BioPharma Partners II, L.P. ------------------------------------------------------------------------------------------------------------------- (2) Check The Appropriate Box If A Member Of A Group (a) (b) X ------------------------------------------------------------------------------------------------------------------- (3) SEC Use Only ------------------------------------------------------------------------------------------------------------------- (4) Citizenship or Place of Organization Delaware ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & Footnote 6 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & Footnote 6 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 6 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person PN -------------------------------------------------------------------------------------------------------------------Footnote 6: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 8 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta BioPharma Management Partners II, 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 Delaware ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & footnote 7 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & footnote 7 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 7 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person CO -------------------------------------------------------------------------------------------------------------------Footnote 7: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 9 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alta Embarcadero BioPharma Partners II, 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 Delaware ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power -0- Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & footnote 8 -------------------------------------------------------------- (7) Sole Dispositive Power -0- -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & footnote 8 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,097,880 Please see Attachment A and Footnote 8 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.91% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person CO -------------------------------------------------------------------------------------------------------------------Footnote 8: Includes the 837,463 shares of Common Stock and Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. See Attachment A. CUSIP No. 766559108 Page 10 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Farah Champsi ------------------------------------------------------------------------------------------------------------------- (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 ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power 1,998 Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,063,157 Please see Attachment A & footnote 9 -------------------------------------------------------------- (7) Sole Dispositive Power 1,998 -------------------------------------------------------------- (8) Shared Dispositive Power 1,063,157 Please see Attachment A & footnote 9 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,065,155 Please see Attachment A and Footnote 9 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.67% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person IN ------------------------------------------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!Footnote 9: Includes the 837,463 shares of Common Stock and Warrants to purchase 225,694 shares of Common Stock held by the funds affiliated with Alta Partners II. As a result of the Alta Partners II stock distribution on 8/20/04, the 1999 Farah Champsi Revocable Trust received 1,998 shares of Common Stock. CUSIP No. 766559108 Page 11 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Jean Deleage ------------------------------------------------------------------------------------------------------------------- (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 ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power 29,038 Beneficially Owned -By Each Reporting ------------------------------------------------------------- Person With (6) Shared Voting Power 1,097,880 Please see Attachment A & footnote -------------------------------------------------------------- (7) Sole Dispositive Power 29,038 -------------------------------------------------------------- (8) Shared Dispositive Power 1,097,880 Please see Attachment A & footnote 10 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,126,918 Please see Attachment A and footnote 10 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.99% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person IN ------------------------------------------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!Footnote 10: Includes the 837,463 shares of Common Stock, Warrants to purchase 260,417 shares of Common Stock held by the funds affiliated with Alta Partners and Alta Partners II. He received 9,593 shares of Common Stock from the Alta Partners and Alta Partners II stock distribution on 8/20/04. He also holds Stock Options for 19,445 shares of Common Stock. See Attachment A. CUSIP No. 766559108 Page 12 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Garrett Gruener ------------------------------------------------------------------------------------------------------------------- (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 ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power 15,864 Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 34,723 Please see Attachment A & footnote 11 -------------------------------------------------------------- (7) Sole Dispositive Power 15,864 -------------------------------------------------------------- (8) Shared Dispositive Power 34,723 Please see Attachment A & footnote 11 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 50,587 Please see Attachment A and footnote 11 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 0.27% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person IN ------------------------------------------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!Footnote 11: Includes Warrants to purchase 34,723 shares of Common Stock held by the funds affiliated with Alta Partners. He received 15,864 shares of Common Stock from the Alta Partners stock distribution on 8/20/04. See Attachment A. CUSIP No. 766559108 Page 13 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Alix Marduel ------------------------------------------------------------------------------------------------------------------- (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 ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power 2,378 Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 1,063,157 Please see Attachment A & footnote 12 -------------------------------------------------------------- (7) Sole Dispositive Power 2,378 ` -------------------------------------------------------------- (8) Shared Dispositive Power 1,063,157 Please see Attachment A & footnote 12 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 1,065,535 Please see Attachment A and Footnote 12 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 5.67% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person IN ------------------------------------------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!Footnote 12: Includes the 837,463 shares of Common Stock and Warrants to purchase 225,694 shares of Common Stock held by the funds affiliated with Alta Partners II. As a result of the Alta Partners II stock distribution on 8/20/04, the Lockard/Marduel Revocable Trust received 2,378 shares of Common Stock. CUSIP No. 766559108 Page 14 of 18 Pages ------------------------------------------------------------------------------------------------------------------- (1) Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons Guy Nohra ------------------------------------------------------------------------------------------------------------------- (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 ------------------------------------------------------------------------------------------------------------------- Please see Attachment A Number Of Shares (5) Sole Voting Power 15,122 Beneficially Owned By Each Reporting -------------------------------------------------------------- Person With (6) Shared Voting Power 34,723 Please see Attachment A & footnote 13 -------------------------------------------------------------- (7) Sole Dispositive Power 15,112 -------------------------------------------------------------- (8) Shared Dispositive Power 34,723 Please see Attachment A & footnote 13 ------------------------------------------------------------------------------------------------------------------- (9) Aggregate Amount Beneficially Owned By Each Reporting Person 49,845 Please see Attachment A and Footnote 13 ------------------------------------------------------------------------------------------------------------------- (10) Check If The Aggregate Amount In Row (11) Excludes Certain Shares* ------------------------------------------------------------------------------------------------------------------- (11) Percent Of Class Represented By Amount In Row (11) 0.27% Please see Attachment A ------------------------------------------------------------------------------------------------------------------- (12) Type Of Reporting Person IN ------------------------------------------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!Footnote 13: Includes Warrants to purchase 34,723 shares of Common Stock held by the funds affiliated with Alta Partners. As a result of the Alta Partners stock distribution on 8/20/04, the Nohra Living Trust received 11,442 shares of Common Stock and the Nohra 1996 Credit Trust received 3,680 shares of Common Stock. Item 1. (a) Name of Issuer: Rigel Pharmaceuticals, Inc. ("Issuer") (b) Address of Issuer's Principal Executive Offices: 1180 Veterans Boulevard South San Francisco, CA 94080 Item 2. (a) Name of Person Filing: Alta Partners ("AP") Alta Partners II, Inc. ("AP II") Alta California Partners, L.P. ("ACP") Alta California Management Partners, L.P. ("ACMP") Alta Embarcadero Partners, LLC ("AEP") Alta BioPharma Partners II, L.P. ("ABP II") Alta BioPharma Management Partners II, LLC ("ABMP II") Alta Embarcadero BioPharma Partners II, LLC ("AEBP II") Farah Champsi ("FC") Jean Deleage ("JD") Garrett Gruener ("GG") Alix Marduel ("AM") Guy Nohra ("GN") (b) Address of Principal Business Office: One Embarcadero Center, Suite 4050 San Francisco, CA 94111 (c) Citizenship/Place of Organization: Entities: AP California AP II California ACP Delaware ACMP Delaware AEP California ABP II Delaware ABMP II Delaware AEBP II California Individuals: FC United States JD United States GG United States AM United States GN United States (d) Title of Class of Securities: Common Stock (e) CUSIP Number: 766559108 Item 3. Not applicable. Item 4 Ownership. Please see Attachment A ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- AP AP II ACP ACMP AEP ABP II ABMP II ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- (a) Beneficial 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 Ownership ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- (b) Percentage of 5.91% 5.91% 5.91% 5.91% 5.91% 5.91% 5.91% Class ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- (c) Sole Voting Power -0- -0- -0- -0- -0- -0- -0- ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- Shared Voting 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 Power ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- Sole Dispositive -0- -0- -0- -0- -0- -0- -0- Power ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- Shared 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 1,097,880 Dispositive Power ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- AEBP II FC JD GG AM GN ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- (a) Beneficial 1,097,880 1,065,155 1,126,918 50,587 1,065,535 49,845 Ownership ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- (b) Percentage of 5.91% 5.67% 5.99% 0.27% 5.67% 0.27% Class ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- (c) Sole Voting Power -0- 1,998 29,038 15,864 2,378 15,122 ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- Shared Voting 1,097,880 1,063,157 1,097,880 34,723 1,063,157 34,723 Power ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- Sole Dispositive -0- 1,998 29,038 15,864 2,378 15,122 Power ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- Shared 1,097,880 1,063,157 1,097,880 34,723 1,063,157 34,723 Dispositive Power ------- ------------------ ----------- ----------- ------------ ----------- ------------- ------------ ------------- 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 Not applicable. 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)(ii)(H) of the Act. Item 9. Notice of Dissolution of Group Not applicable. Item 10. Certification By signing below we certify that, to the best of our knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. EXHIBITS A: Joint Filing Statement 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: August 30, 2004 ALTA PARTNERS ALTA CALIFORNIA PARTNERS, L.P. By: Alta California Management Partners, L.P., By: /s/ Jean Deleage By: /s/ Jean Deleage . ----------------------------------------- ------------------------------------------ Jean Deleage, President Jean Deleage, General Partner ALTA CALIFORNIA MANAGEMENT PARTNERS, L.P. ALTA EMBARCADERO PARTNERS, LLC By: /s/ Jean Deleage By: /s/ Jean Deleage ----------------------------------------- ----------------------------------------- Jean Deleage, General Partner Jean Deleage, Member ALTA PARTNERS II, INC. By: /s/ Jean Deleage ----------------------------------------- Jean Deleage, President ALTA BIOPHARMA PARTNERS II, L.P. ALTA BIOPHARMA MANAGEMENT PARTNERS II, LLC By: Alta BioPharma Management Partners II, LLC By: /s/ Farah Champsi By: /s/ Farah Champsi ----------------------------------------- ----------------------------------------- Farah Champsi, Managing Director Farah Champsi, Managing Director ALTA EMBARCADERO BIOPHARMA PARTNERS II, LLC By: /s/ Farah Champsi /s/ Alix Marduel ----------------------------------------- -------------------------------------------- Farah Champsi, Manager Alix Marduel /s/ Jean Deleage /s/ Guy Nohra ----------------------------------------- -------------------------------------------- Jean Deleage Guy Nohra /s/ Garrett Gruener /s/ Farah Champsi ----------------------------------------- -------------------------------------------- Garrett Gruener Farah Champsi EXHIBIT A AGREEMENT OF JOINT FILING Date: August 30, 2004 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. ALTA PARTNERS ALTA CALIFORNIA PARTNERS, L.P. By: Alta California Management Partners, L.P., By: /s/ Jean Deleage By: /s/ Jean Deleage . ----------------------------------------- ------------------------------------------ Jean Deleage, President Jean Deleage, General Partner ALTA CALIFORNIA MANAGEMENT PARTNERS, L.P. ALTA EMBARCADERO PARTNERS, LLC By: /s/ Jean Deleage By: /s/ Jean Deleage ----------------------------------------- ----------------------------------------- Jean Deleage, General Partner Jean Deleage, Member ALTA PARTNERS II, INC. By: /s/ Jean Deleage ----------------------------------------- Jean Deleage, President ALTA BIOPHARMA PARTNERS II, L.P. ALTA BIOPHARMA MANAGEMENT PARTNERS II, LLC By: Alta BioPharma Management Partners II, LLC By: /s/ Farah Champsi By: /s/ Farah Champsi ----------------------------------------- ----------------------------------------- Farah Champsi, Managing Director Farah Champsi, Managing Director ALTA EMBARCADERO BIOPHARMA PARTNERS II, LLC By: /s/ Farah Champsi /s/ Alix Marduel ----------------------------------------- -------------------------------------------- Farah Champsi, Manager Alix Marduel /s/ Jean Deleage /s/ Guy Nohra ----------------------------------------- ----------------------------------------- Jean Deleage Guy Nohra /s/ Garrett Gruener /s/ Farah Champsi ----------------------------------------- ----------------------------------------- Garrett Gruener Farah Champsi Attachment A Alta Partners provides investment advisory services to several venture capital funds including Alta California Partners, L.P. and Alta Embarcadero Partners, LLC. On August 20, 2004, Alta California distributed 352,434 shares of Common Stock to its general and limited partners, and Alta Embarcadero Partners, LLC distributed 8,049 shares of Common Stock to its members. As a result of the distribution, Alta California Partners, L.P. now beneficially owns Warrants to purchase 33,947 shares of Common Stock, and Alta Embarcadero Partners, LLC now beneficially owns Warrants to purchase 776 shares of Common Stock. The respective general partners and members of Alta California Partners L.P. and Alta Embarcadero Partners, LLC exercise sole voting and investment power with respect to the shares owned by such funds. Certain principals of Alta Partners are general partners of Alta California Management Partners, L.P. (which is a general partner of Alta California Partners, L.P.), and members Alta Embarcadero Partners, LLC. As general partners and members of such funds, they may be deemed to share voting and investment powers over the shares held by the funds. The principals of Alta Partners disclaim beneficial ownership of all such shares held by the foregoing funds, except to the extent of their proportionate pecuniary interests therein. Alta Partners II, Inc. provides investment advisory services to several venture capital funds including Alta BioPharma Partners II, L.P. and Alta Embarcadero BioPharma Partners II, LLC. On August 20, 2004, Alta BioPharma Partners II, L.P. distributed 403,892 shares of Common Stock to its general and limited partners, and Alta Embarcadero BioPharma Partners II, LLC distributed 14,858 shares of Common Stock to its members. As a result of the distribution, Alta BioPharma Partners II, L.P. now beneficially owns 807,748 shares of Common Stock and Warrants to purchase 217,686 shares of Common stock, and Alta Embarcadero BioPharma Partners II, LLC now beneficially owns 29,715 shares Common Stock and Warrants to purchase 8,008 shares of Common Stock. The managing directors of Alta BioPharma Partners II, L.P. and managers of Alta Embarcadero BioPharma Partners II, LLC exercise sole voting and investment power in respect to the shares owned by such funds. Certain principals of Alta Partners II, Inc. are managing directors of Alta BioPharma Management II, LLC (which is the general partner of Alta BioPharma Partners II, L.P.), and managers of Alta Embarcadero BioPharma Partners II, LLC. As managing directors and managers of such entities, they may be deemed to share voting and investment powers over the shares beneficially held by the funds. The principals of Alta Partners II, Inc. disclaim beneficial ownership of all such shares held by the foregoing funds, except to the extent of their proportionate pecuniary interests therein. Mr. Jean Deleage, Director, is a managing director of Alta BioPharma Management Partners II, LLC (which is the general partner of Alta BioPharma Partners II, L.P.), a manager of Alta Embarcadero BioPharma Partners II, LLC, a general partner of Alta California Management Partners, L.P. (which is the general partner of Alta California Partners, L.P.), and a member of Alta Embarcadero Partners, LLC. Thus he currently shares voting and dispositive powers over the 807,748 shares of Common Stock beneficially owned by Alta BioPharma Partners II, L.P., and the 29,715 shares of Common Stock beneficially owned by Alta Embarcadero BioPharma Partners II, LLC. He disclaims beneficial ownership of all such shares held by all of the foregoing funds except to the extent of his proportionate pecuniary interests therein. As a result of the Alta Partners and Alta Partners II, Inc. stock distributions, Mr. Deleage received a total of 9,593 shares of Common Stock. He holds stock options for 19,445 shares of Common Stock: options for 8,333 shares were granted on June 30, 2004, options for 8,333 shares were granted on January 26, 2004, options for 1,667 shares were granted on June 26, 2003, options for 556 shares were granted on June 20, 2002 and options for 556 shares were granted on July 19, 2001. Ms. Farah Champsi is a managing director of Alta BioPharma Management Partners II, LLC (which is the general partner of Alta BioPharma Partners II, L.P.) and a manager of Alta Embarcadero BioPharma Partners II, LLC. Thus she currently shares voting and dispositive powers over the 807,748 shares of Common Stock beneficially owned by Alta BioPharma Partners II, L.P. and the 29,715 shares of Common Stock beneficially owned by Alta Embarcadero BioPharma Partners II, LLC. She disclaims beneficial ownership of all such shares held by all of the foregoing funds except to the extent of her proportionate pecuniary interests therein. As a result of the Alta Partners II stock distribution on 8/20/04, the 1999 Farah Champsi Revocable Trust received 1,998 shares of Common Stock. Page 1 of 2 of Attachment A Attachment A (continued) Mr. Garrett Gruener is a general partner of Alta California Management Partners, L.P. (which is the general partner of Alta California Partners, L.P.) and a member of Alta Embarcadero Partners, LLC. He disclaims beneficial ownership of all such shares held by all of the foregoing funds except to the extent of his proportionate pecuniary interests therein. Mr. Gruener received 15,864 shares from the Alta Partners stock distribution on 8/20/04. Dr. Alix Marduel is a managing director of Alta BioPharma Management Partners II, LLC (which is the general partner of Alta BioPharma Partners II, L.P.) and a manager of Alta Embarcadero BioPharma Partners II, LLC. Thus she currently shares voting and dispositive powers over the 807,748 shares of Common Stock beneficially owned by Alta BioPharma Partners II, L.P. and the 2,915 shares of Common Stock beneficially owned by Alta Embarcadero BioPharma Partners II, LLC. She disclaims beneficial ownership of all such shares held by all of the foregoing funds except to the extent of her proportionate pecuniary interests therein. As a result of the Alta Partners II stock distribution on 8/20/04, the Lockard/Marduel Revocable Trust received 2,378 shares of Common Stock. Mr. Guy Nohra is a general partner of Alta California Management Partners, L.P. (which is the general partner of Alta California Partners, L.P.). He disclaims beneficial ownership of all such shares held by all of the foregoing funds except to the extent of his proportionate pecuniary interests therein. As a result of the Alta Partners stock distribution on 8/20/04, the Nohra Living Trust received 11,442 shares of Common Stock and the Nohra 1996 Credit Trust received 3,680 shares of Common Stock. Alta Partners and Alta Partners II, Inc. are venture capital firms that share an office in San Francisco. Alta Partners is California Corporation. Alta Partners II, Inc. is a California Corporation. Alta California Partners, L.P. is a Delaware Limited Partnership, Alta Embarcadero Partners, LLC is a California Limited Liability Company, Alta BioPharma Partners II, L.P. is a Delaware Limited Partnership, and Alta Embarcadero BioPharma Partners II, LLC is a California Limited Liability Company. Page 2 of 2 of Attachment A