Ownership Submission
FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF 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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(Print or Type Responses)
1. Name and Address of Reporting Person *
  GLAXOSMITHKLINE PLC
2. Date of Event Requiring Statement (Month/Day/Year)
12/18/2006
3. Issuer Name and Ticker or Trading Symbol
EPIX Pharmaceuticals, Inc. [EPIX]
(Last)
(First)
(Middle)
980 GREAT WEST ROAD
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

BRENTFORD MIDDLESEX, X0 TW8 9GS
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 Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common stock 4,266,795
I
by Corporation (1) (2) (3)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
GLAXOSMITHKLINE PLC
980 GREAT WEST ROAD
BRENTFORD MIDDLESEX, X0 TW8 9GS
    X    

Signatures

Victoria A. Whyte, Deputy Secretary 12/21/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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) On December 18, 2006, Glaxo Group Limited ("GGL") and SmithKline Beecham Corporation ("SBCorp"), indirect wholly-owned subsidiaries of Reporting Person, purchased 1,629,689 and 1,379,338 shares of Common stock, respectively, pursuant to a Stock Purchase Agreement dated December 11, 2006 between GGL, SBCorp and the Issuer.
(2) S.R.One, Limited ("SRO"), another indirect wholly-owned subsidiary of Reporting Person, previously acquired 1,257,768 shares of Common stock but was not required to file under Section 16(a) of the Securities Exchange Act of 1934, as amended (the "Act").
(3) All shares covered by this report are beneficially owned by indirect wholly-owned subsidiaries of Reporting Person. The Reporting Person may be deemed, for purposes of Section 16 of the Act to be the beneficial owner of GGL, SBCorp and SRO and, therefore, may be deemed to be a "10 percent beneficial owner" for purposes of Section 16 of the Act.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

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