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* Clarus Lifesciences II, L.P. (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ACHILLION PHARMACEUTICALS INC [ ACHN ]	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) 12/24/2009
	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	12/24/2009		S(1)		3,600	D	$3.5264	4,673,567	I	By Fund(2)

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* Clarus Lifesciences II, L.P. (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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* Clarus Ventures II GP, L.P. (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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* Clarus Ventures II, LLC (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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* LIPTAK ROBERT (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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* Simon Nicholas (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* HENNER DENNIS (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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* GALAKATOS NICHOLAS (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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* Leiden Jeffrey (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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* WHEELER KURT (Last) (First) (Middle) C/O CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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 CLARUS VENTURES, LLC 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (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. The sales reported on this Form 4 were effected pursuant to Rule 10b5-1 trading plan adpoted by Clarus Lifesciences II, L.P. (the "Fund") on November 1, 2009.

2. Securities held of record by the Fund. Clarus Ventures II GP, L.P. (the "GPLP"), as the sole general partner of the Fund, may be deemed to beneficially own certain of the shares held of record by the Fund. The GPLP disclaims beneficial ownership of all shares held of record by the Fund in which the GPLP does not have an actual pecuniary interest. Clarus Ventures II, LLC (the "GPLLC"), as the sole general partner of the GPLP, may be deemed to beneficially own certain of the shares held of record by the Fund. Each of Messrs. Galakatos, Henner, Leiden, Liptak, Simon, Steinmetz and Wheeler, as individual Managing Directors of the GPLLC, may be deemed to beneficially own certain of the shares held of record by the Fund. Each of Messrs. Galakatos, Henner, Leiden, Liptak, Simon, Steinmetz and Wheeler disclaims beneficial ownership of all shares held of record by the Fund in which he does not have an actual pecuniary interest.

Remarks:

	/s/ Robert Liptak, Manager of Clarus Ventures II, LLC, general partner of Clarus Ventures II GP, L.P., general partner of Clarus Lifesciences II, L.P.	12/29/2009
	/s/ Robert Liptak, Maganer of Clarus Ventures II, LLC, general partner of Clarus Ventures II GP, L.P.	12/29/2009
	/s/ Robert Liptak, Manager of Clarus Ventures II, LLC	12/29/2009
	/s/ Robert Liptak, as attorney-in-fact for Nicholas Simon	12/29/2009
	/s/ Robert Liptak	12/29/2009
	/s/ Robert Liptak, as attorney-in-fact for Dennis Henner	12/29/2009
	/s/ Robert Liptak, as attorney-in-fact for Nicholas Galakatos	12/29/2009
	/s/ Robert Liptak, as attorney-in-fact for Jeffrey Leiden	12/29/2009
	/s/ Robert Liptak, as attorney-in-fact for Kurt Wheeler	12/29/2009
	/s/ Robert Liptak, as attorney-in-fact for Michael Steinmetz	12/29/2009
	** Signature of Reporting Person	Date
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* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
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