FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN 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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1. Name and Address of Reporting Person * BB BIOVENTURES L P   2. Issuer Name and Ticker or Trading Symbol Pharmasset Inc [VRUS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT, 200 CLARENDON STREET, 54TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 06/17/2008 (Street) BOSTON, MA 02116 4. If Amendment, Date Original Filed(Month/Day/Year) 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 Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 06/17/2008   S   99,800 (1) D $ 20.15 2,276,231 I See Footnote (2) Common Stock 06/17/2008   S   100 (3) D $ 20.16 2,276,131 I See Footnote (4) Common Stock 06/17/2008   S   100 (5) D $ 20.17 2,276,031 I See Footnote (6) Common Stock 06/17/2008   S   1,900 (7) D $ 20.25 2,274,131 I See Footnote (8) Common Stock               57,353 I See Footnote (9)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
BB BIOVENTURES L P C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
BAB BIO VENTURES LLP C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
BAB BIO VENTURES NV C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM ASSET MANAGEMENT INVESTORS 1999 LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BIOVENTURES PARALLEL FUND L P C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BIOVENTURES I LP C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BIO VENTURES I LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
EVNIN LUKE C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
STEINMETZ MICHAEL C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
GADICKE ANSBERT C/O MPM ASSET MANAGEMENT 200 CLARENDON ST., 54TH FLOOR BOSTON, MA 02116		X

Signatures

By Ansbert Gadicke, managing director of BAB BioVentures NV, the general partner of BAB BioVentures L.P., the general partner of BB BioVentures L.P. /s/ Ansbert Gadicke		06/18/2008
**Signature of Reporting Person		Date
By Ansbert Gadicke, managing director of BAB BioVentures NV, the general partner of BAB BioVentures L.P. /s/ Ansbert Gadicke		06/18/2008
**Signature of Reporting Person		Date
By Ansbert Gadicke, managing director of BAB BioVentures NV /s/ Ansbert Gadicke		06/18/2008
**Signature of Reporting Person		Date
By Luke Evnin, manager of MPM Asset Management Investors 1999 LLC /s/ Luke Evnin		06/18/2008
**Signature of Reporting Person		Date
By Luke Evnin, manager of MPM BioVentures I LLC, the general partner of MPM BioVentures I L.P., the general partner of MPM BioVentures Parallel Fund, L.P. /s/ Luke Evnin		06/18/2008
**Signature of Reporting Person		Date
By Luke Evnin, manager of MPM BioVentures I LLC, the general partner of MPM BioVentures I L.P. /s/ Luke Evnin		06/18/2008
**Signature of Reporting Person		Date
By Luke Evnin, manager of MPM BioVentures I LLC /s/ Luke Evnin		06/18/2008
**Signature of Reporting Person		Date
/s/ Luke Evnin		06/18/2008
**Signature of Reporting Person		Date
/s/ Michael Steinmetz		06/18/2008
**Signature of Reporting Person		Date
/s/ Ansbert Gadicke		06/18/2008
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(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 shares were sold as follows: 44,407 shares by BB BioVentures, L.P. ("BBBV"), 5,986 shares by MPM BioVentures Parallel Fund, L.P. ("BV PF"), 529 shares by MPM Asset Management Investors 1999 LLC ("AM 1999"), 2,578 shares by MPM BioVentures III, L.P., ("BV III"), 38,358 shares by MPM BioVentures III-QP, L.P. ("BV III QP"), 3,242 shares held by MPM BioVentures III GmbH & Co. Beteiligungs KG ("BV KG"), 1,159 shares by MPM BioVentures III Parallel Fund, L.P. ("BV III PF"), 912 shares held by MPM Asset Management Investors 2004 BVIII LLC ("AM BV III"), 2,564 by MPM BioVentures III GP, LP ("BV III GP") and 65 by MPM Capital, L.P. ("MPM LP"). MPM BioVentures I, L.P. ("BV I") and MPM BioVentures I LLC ("BV I LLC") are the direct and indirect general partners of BV PF. BAB BioVentures L.P. ("BAB BV"), BAB BioVentures, N.V. ("BAB NV") and BV I LLC are the direct and indirect general partners of BBBV. Luke Evnin, Michael Steinmetz and Ansbert Gadicke are the managers of AM 1999 and BV I LLC. BV III GP and MPM BioVentures III LLC ("BV III LLC") are the direct and indirect general partners of BV III, BV III QP, BV III PF and BV KG. Luke Evnin, Michael Steinmetz and Ansbert Gadicke are Series A members of BV III LLC and managers of AM BV III. Luke Evnin and Ansbert Gadicke have a controlling interest in MPM LP. Each Reporting Person disclaims beneficial ownership of all such shares except to the extent of their respective proportionate pecuniary interests therein.
(2)	The shares are held as follows: 1,012,832 by BBBV, 136,540 by BV PF, 12,078 by AM 1999, 58,827 by BV III, 874,832 by BV III QP, 73,929 by BV KG, 26,421 by BV III PF, 20,796 by AM BV III, 58,506 by BV III GP and 1,470 by MPM LP. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of their respective proportionate pecuniary interest therein.
(3)	The shares were sold as follows: 44 by BBBV, 6 by BV PF, 1 by AM 1999, 3 by BV III, 38 by BV III QP, 3 by BV KG, 1 by BV III PF, 1 by AM BV III and 3 by BV III GP.
(4)	The shares are held as follows: 1,012,788 by BBBV, 136,534 by BV PF, 12,077 by AM 1999, 58,824 by BV III, 874,794 by BV III QP, 73,926 by BV KG, 26,420 by BV III PF, 20,795 by AM BV III, 58,503 by BV III GP and 1,470 by MPM LP. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of their respective proportionate pecuniary interest therein.
(5)	The shares were sold as follows: 44 by BBBV, 6 by BV PF, 1 by AM 1999, 3 by BV III, 38 by BV III QP, 3 by BV KG, 1 by BV III PF, 1 by AM BV III and 3 by BV III GP.
(6)	The shares are held as follows: 1,012,744 by BBBV, 136,528 by BV PF, 12,076 by AM 1999, 58,821 by BV III, 874,756 by BV III QP, 73,923 by BV KG, 26,419 by BV III PF, 20,794 by AM BV III,58,500 by BV III GP and 1,470 by MPM LP. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of their respective proportionate pecuniary interest therein.
(7)	The shares were sold as follows: 846 by BBBV, 114 by BV PF, 10 by AM 1999, 49 by BV III, 730 by BV III QP, 62 by BV KG, 22 by BV III PF, 17 by AM BV III, 49 by BV III GP and 1 by MPM LP.
(8)	The shares are held as follows: 1,011,898 by BBBV, 136,414 by BV PF, 12,066 by AM 1999, 58,772 by BV III, 874,026 by BV III QP, 73,861 by BV KG, 26,397 by BV III PF, 20,777 by AM BV III, 58,451 by BV III GP and 1,469 by MPM LP. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of their respective proportionate pecuniary interest therein.
(9)	The shares are held by Luke Evnin.

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