Sec Form 4 Filing - WHITE CHRISTOPHER A @ ACHILLION PHARMACEUTICALS INC - 2006-10-31

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 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 WHITE CHRISTOPHER A 2. Issuer Name and Ticker or Trading Symbol ACHILLION PHARMACEUTICALS INC [ ACHN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O ACHILLION PHARMACEUTICALS, 300 GEORGE STREET 3. Date of Earliest Transaction (MM/DD/YY) 10/31/2006 (Street) NEW HAVEN, CT06511 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 10/31/2006 C 2,242 A $ 0 2,242 D Common Stock 10/31/2006 C 922,451 ( 1 ) A $ 0 922,451 ( 1 ) I See Footnote ( 1 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Series C Convertible Preferred Stock ( 2 ) 10/31/2006 C 5,125,639 ( 4 ) ( 5 ) ( 2 ) ( 3 ) Common Stock 766,143 ( 5 ) ( 7 ) $ 0 0 I See Footnote ( 8 ) Series C-2 Convertible Preferred Stock ( 2 ) 10/31/2006 C 17,941 ( 5 ) ( 2 ) ( 3 ) Common Stock 2,242 ( 5 ) $ 0 0 D Series C-2 Convertible Preferred Stock ( 2 ) 10/31/2006 C 1,250,476 ( 5 ) ( 6 ) ( 2 ) ( 3 ) Common Stock 156,308 ( 5 ) ( 6 ) $ 0 0 I See Footnote ( 6 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other WHITE CHRISTOPHER A C/O ACHILLION PHARMACEUTICALS 300 GEORGE STREET NEW HAVEN, CT06511 X Signatures /s/ Christopher A. White 11/01/2006 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Consists of 222,428 shares held by SG Cowen Ventures I L.P. and 700,023 shares held by SGC Partners I LLC. Mr. White disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein. ( 2 )Upon the closing of the issuer's initial public offering, each share of Series C Convertible Preferred Stock automatically converted into approximately 0.149 shares of common stock and each share of Series C-2 Convertible Preferred Stock automatically converted into approximately 0.125 shares of common stock. The Series C and Series C-2 Convertible Preferred Stock conversion rates reflect the 1-for-8 reverse stock split, which became effective on October 24, 2006. ( 3 )Not applicable ( 4 )Consists of 1,488,088 shares held by SG Cowen Ventures I LP and 3,637,551 shares held by SGC Partners I LLC. Mr. White disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein. ( 5 )Includes shares of preferred stock issued as a dividend which was paid upon the conversion of the preferred stock. ( 6 )Consists of shares held by SGC Partners I LLC. Mr. White disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein. ( 7 )Consists of 222,428 shares held by SG Cowen Ventures I L.P. and 543,715 shares held by SGC Partners I LLC. Mr. White disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein. ( 8 )Consists of shares held by SG Cowen Ventures I LP and SGC Partners I LLC. Mr. White disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.

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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