SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* BB BIOVENTURES L P (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)	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)
	3. Date of Earliest Transaction (Month/Day/Year) 02/07/2008
	4. If Amendment, Date of 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

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	02/07/2008		S		36,664(1)	D	$23.02	2,587,168	I	See Footnote(2)
Common Stock								57,353	I	See Footnote(3)
Common Stock	02/08/2008		S		27,925	D	$21.36	0	I	See Footnote(4)
Common Stock								35,558	I	See Footnote(5)

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 Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* BB BIOVENTURES L P (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* BAB BIO VENTURES LLP (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* BAB BIO VENTURES NV (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM ASSET MANAGEMENT INVESTORS 1999 LLC (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM BIOVENTURES PARALLEL FUND L P (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM BIOVENTURES I LP (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM BIO VENTURES I LLC (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* EVNIN LUKE (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* STEINMETZ MICHAEL (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* GADICKE ANSBERT (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. These shares were sold as follows: 16,755 shares by BB BioVentures, L.P. ("BBBV"), 2,259 shares by MPM BioVentures Parallel Fund, L.P. ("BV PF"), 200 shares by MPM Asset Management Investors 1999 LLC ("AM 1999"), 973 shares by MPM BioVentures III, L.P., ("BV III"), 14,473 shares by MPM BioVentures III-QP, L.P. ("BV III QP"), 1,223 shares held by MPM BioVentures III GmbH & Co. Beteiligungs KG ("BV KG"), 437 shares by MPM BioVentures III Parallel Fund, L.P. ("BV III PF") and 344 shares held by MPM Asset Management Investors 2004 BVIII LLC ("AM BV III"). 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. MPM BioVentures III GP, L.P. ("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 members of BV III LLC and AM BV III. 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: 1,182,339 by BBBV, 159,391 by BV PF, 14,099 by AM 1999, 68,671 by BV III, 1,021,244 by BV III QP, 86,303 by BV KG, 30,844 by BV III PF and 24,277 by AM BV III. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of their respective proportionate pecuniary interest therein.

3. The shares are held by Luke Evnin.

4. The shares were held by Michael Steinmetz.

5. The shares are held as follows: 29,369 by Ansbert Gadicke and 6,189 by The Gadicke Irrevocable Trust, of which Mr. Gadicke is a trustee. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein.

	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	02/11/2008
	By Ansbert Gadicke, managing director of BAB BioVentures NV, the general partner of BAB BioVentures L.P. /s/ Ansbert Gadicke	02/11/2008
	By Ansbert Gadicke, managing director of BAB BioVentures NV /s/ Ansbert Gadicke	02/11/2008
	By Luke Evnin, manager of MPM Asset Management Investors 1999 LLC /s/ Luke Evnin	02/11/2008
	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	02/11/2008
	By Luke Evnin, manager of MPM BioVentures I LLC, the general partner of MPM BioVentures I L.P. /s/ Luke Evnin	02/11/2008
	By Luke Evnin, manager of MPM BioVentures I LLC /s/ Luke Evnin	02/11/2008
	/s/ Luke Evnin	02/11/2008
	/s/ Michael Steinmetz	02/11/2008
	/s/ Ansbert Gadicke	02/11/2008
	** Signature of Reporting Person	Date
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