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) 06/17/2008
	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	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)

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 ST., 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: 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.

	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
	By Ansbert Gadicke, managing director of BAB BioVentures NV, the general partner of BAB BioVentures L.P. /s/ Ansbert Gadicke	06/18/2008
	By Ansbert Gadicke, managing director of BAB BioVentures NV /s/ Ansbert Gadicke	06/18/2008
	By Luke Evnin, manager of MPM Asset Management Investors 1999 LLC /s/ Luke Evnin	06/18/2008
	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	06/18/2008
	By Luke Evnin, manager of MPM BioVentures I LLC, the general partner of MPM BioVentures I L.P. /s/ Luke Evnin	06/18/2008
	By Luke Evnin, manager of MPM BioVentures I LLC /s/ Luke Evnin	06/18/2008
	/s/ Luke Evnin	06/18/2008
	/s/ Michael Steinmetz	06/18/2008
	/s/ Ansbert Gadicke	06/18/2008
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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