UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934

                           (Amendment No. _________)*

                           EPIX Pharmaceuticals, Inc.
                                (Name of Issuer)

                     Common Stock, $0.01 par value per share
                         (Title of Class of Securities)

                                    26881Q101
                                 (CUSIP Number)

                                  April 3, 2006
             (Date of Event Which Requires Filing of this statement)


     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:
     [ ]  Rule 13d-1(b)
     [X]  Rule 13d-1(c)
     [ ]  Rule 13d-1(d)





----------------
     *The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act
of 1934 ("Act") or otherwise subject to the liabilities of that section of the
Act but shall be subject to all other provisions of the Act (however, see the
Notes).

                               Page 1 of 12 Pages



CUSIP No. 26881Q101                  13G                    Page 2 of 12 Pages
----------------------------------------------------------------------
     (1) NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

         GLG Partners LP
-----------------------------------------------------------------------
     (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                               (a)  [X]
                                                               (b)  [ ]
-----------------------------------------------------------------------
     (3) SEC USE ONLY
-----------------------------------------------------------------------
     (4) CITIZENSHIP OR PLACE OF ORGANIZATION

            England
-----------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         --------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,173,975 shares of Common Stock
OWNED BY       --------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------

PERSON WITH:  (8)  SHARED DISPOSITIVE POWER
                    1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (10) CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
                                                                    [ ]
-----------------------------------------------------------------------
     (11) PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.04%
-----------------------------------------------------------------------
     (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
          PN
-----------------------------------------------------------------------




CUSIP No. 26881Q101                  13G                    Page 3 of 12 Pages
-----------------------------------------------------------------------
     (1)  NAMES OF REPORTING PERSONS
          I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

          GLG Partners Limited
-----------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                               (a)  [X]
                                                               (b)  [ ]
-----------------------------------------------------------------------
     (3)  SEC USE ONLY
-----------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION

          England
-----------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         --------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,173,975 shares of Common Stock
OWNED BY       --------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------

PERSON WITH:   (8)  SHARED DISPOSITIVE POWER
                    1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (10) CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
                                                                   [ ]
-----------------------------------------------------------------------
     (11) PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.04%
-----------------------------------------------------------------------
     (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
          OO
-----------------------------------------------------------------------




CUSIP No. 26881Q101                  13G                    Page 4 of 12 Pages
-----------------------------------------------------------------------
     (1)  NAMES OF REPORTING PERSONS
          I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

          Noam Gottesman
-----------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                               (a)  [X]
                                                               (b)  [ ]
-----------------------------------------------------------------------
     (3)  SEC USE ONLY
-----------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION

          United States
-----------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         --------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,173,975 shares of Common Stock
OWNED BY       --------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------

PERSON WITH:   (8)  SHARED DISPOSITIVE POWER
                    1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (10) CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
                                                                  [ ]
-----------------------------------------------------------------------
     (11) PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.04%
-----------------------------------------------------------------------
     (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
          IN
-----------------------------------------------------------------------




CUSIP No. 26881Q101                  13G                    Page 5 of 12 Pages

-----------------------------------------------------------------------
     (1)  NAMES OF REPORTING PERSONS
          I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

          Pierre Lagrange
-----------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                               (a)  [X]
                                                               (b)  [ ]
-----------------------------------------------------------------------
     (3)  SEC USE ONLY
-----------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION

          Belgium
-----------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         --------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,173,975 shares of Common Stock
OWNED BY       --------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------

PERSON WITH:   (8)  SHARED DISPOSITIVE POWER
                    1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (10) CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
                                                                    [ ]
-----------------------------------------------------------------------
     (11) PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.04%
-----------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
          IN
-----------------------------------------------------------------------




CUSIP No. 26881Q101                  13G                    Page 6 of 12 Pages

-----------------------------------------------------------------------

     (1)  NAMES OF REPORTING PERSONS
          I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

          Emmanuel Roman
-----------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                               (a)  [X]
                                                               (b)  [ ]
-----------------------------------------------------------------------
     (3)  SEC USE ONLY
-----------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION

          France
-----------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         --------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,173,975 shares of Common Stock
OWNED BY       --------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      --------------------------------------------------------

PERSON WITH:   (8)  SHARED DISPOSITIVE POWER
                    1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
          1,173,975 shares of Common Stock
-----------------------------------------------------------------------
     (10) CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
                                                                    [ ]
-----------------------------------------------------------------------
     (11) PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.04%
-----------------------------------------------------------------------
     (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
          IN
-----------------------------------------------------------------------




CUSIP No. 26881Q101                  13G                    Page 7 of 12 Pages

Item 1.

(a)  Name of Issuer

            EPIX Pharmaceuticals, Inc., a Delaware corporation (the "Company").

(b) Address of Issuer's Principal Executive Offices

            161 First Street
            Cambridge, Massachusetts 02142

Item 2(a).  Name of Person Filing
Item 2(b).  Address of Principal Business Office or, if none, Residence
Item 2(c).  Citizenship

            GLG Partners LP
            1 Curzon Street
            London W1J 5HB
            England
            Citizenship: England

            GLG Partners Limited
            c/o GLG Partners LP
            1 Curzon Street
            London W1J 5HB
            England
            Citizenship: England

            Noam Gottesman
            c/o GLG Partners LP
            1 Curzon Street
            London W1J 5HB
            England
            Citizenship: United States

            Pierre Lagrange
            c/o GLG Partners LP
            1 Curzon Street
            London W1J 5HB
            England
            Citizenship: Belgium

            Emmanuel Roman
            c/o GLG Partners LP
            1 Curzon Street
            London W1J 5HB
            England
            Citizenship: France

Item 2(d)  Title of Class of Securities

            Common Stock, $0.01 par value per share ("Common Stock")

Item 2(e)  CUSIP Number

            26881Q101



CUSIP No. 26881Q101                  13G                    Page 8 of 12 Pages

Item 3. If this statement is filed pursuant to ss.ss.240.13d-1(b) or
240.13d-2(b) or (c), check whether the person filing is a:

(a) [ ] Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o).

(b) [ ] Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ] Insurance company as defined in Section 3(a)(19) of the Act (15
        U.S.C. 78c).

(d) [ ] Investment company registered under Section 8 of the Investment
        Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with ss.240.13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with
        ss.240.13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with
        ss.240.13d-1(b)(1)(ii)(G);

(h) [ ] A savings association as defined in Section 3(b) of the Federal Deposit
        Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment
        company under Section 3(c)(14) of the Investment Company Act of 1940 (15
        U.S.C. 80a-3);

(j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

Item 4.   Ownership

            Provide the following information regarding the aggregate number and
percentage of the class of securities of the issuer identified in Item 1.

            (a) Amount beneficially owned:

                As of the date of this filing, GLG Partners LP, GLG Partners
Limited, Noam Gottesman, Pierre Lagrange and Emmanuel Roman may be deemed the
beneficial owner of (i) 752,398 shares of Common Stock held by GLG North
American Opportunity Fund, (ii) 3,771 shares of Common Stock held by GLG
Investments PLC through its subfund, GLG Balanced Fund, (iii) 74,469 shares of
Common Stock held by GLG Investments PLC through its subfund, GLG Capital
Appreciation Fund, (iv) 254,300 shares of Common Stock held by GLG Investments
PLC through its subfund, GLG North American Equity Fund, (v) 22,971 shares of
Common Stock held by GLG Investments IV PLC through its subfund, GLG Capital
Appreciation (Distributing) Fund, (vi) 5,696 shares of Common Stock held by CITI
GLG North American Hedge Fund Ltd., (vii) 22,370 shares of Common Stock held by
Lyxor North American Alternative Equity Fund Ltd., and (viii) 38,000 shares of
Common Stock held by The Century Fund SICAV (each entity referred to in (i)
through (viii) is herein referred to as a "Fund" and, collectively, as the
"Funds").

                GLG Partners LP, an English limited partnership, acts as the
investment manager of each of the Funds and has voting and dispositive power
over the securities held by the Funds. The general partner of GLG Partners LP is
GLG Partners Limited, an English limited company. The shareholders of GLG
Partners Limited are Noam Gottesman, Pierre Lagrange, Philippe Jabre and Lehman




CUSIP No. 26881Q101                  13G                    Page 9 of 12 Pages

(Cayman) Limited, a subsidiary of Lehman Brothers Holdings, Inc., a
publicly-held entity. The managing directors of GLG Partners Limited are Noam
Gottesman, Pierre Lagrange and Emmanuel Roman, and as a result, each has voting
and dispositive power over the securities held by the Funds. GLG Partners LP,
GLG Partners Limited, Noam Gottesman, Pierre Lagrange and Emmanuel Roman
disclaim beneficial ownership of the securities held by the Funds except for
their pecuniary interest therein.

            (b) Percent of class:

                The Company's most recent annual report on Form 10-K that was
filed on March 1, 2006, indicates there were 23,284,810 shares of Common Stock
outstanding as of February 15, 2006. Therefore, based on the Company's
outstanding shares of Common Stock, the reporting persons may be deemed to
beneficially own 5.04% of the outstanding shares of Common Stock of the Company.
The foregoing should not be construed in and of itself as an admission by any
Reporting Person as to beneficial ownership of shares of Common Stock owned by
another Reporting Person.

            (c) Number of shares as to which each Reporting Person has:

                (i)   Sole power to vote or to direct the vote

                      0

                (ii)  Shared power to vote or to direct the vote

                      See Item 4(a) above.

                (iii) Sole power to dispose or to direct the disposition of

                      0

                (iv)  Shared power to dispose or to direct the disposition of

                      See Item 4(a) above.

Item 5.  Ownership of Five Percent or Less of a Class

            If this statement is being filed to report the fact that as of the
date hereof the reporting person has ceased to be the beneficial owner of more
than five percent of the class of securities, check the following: [ ]

Item 6.  Ownership of More than Five Percent on Behalf of Another Person

            Not applicable.

Item  7.   Identification and Classification of the Subsidiary Which Acquired
           the Security Being Reported on by the Parent Holding Company

            Not applicable.

Item 8.  Identification and Classification of Members of the Group

         See Exhibit I.

Item 9.  Notice of Dissolution of Group



CUSIP No. 26881Q101                  13G                    Page 10 of 12 Pages

            Not applicable.

Item 10. Certification

            By signing below each of the undersigned certifies that, to the best
of its knowledge and belief, the securities referred to above were not acquired
and are not held for the purpose of or with the effect of changing or
influencing the control of the issuer of the securities and were not acquired
and are not held in connection with or as a participant in any transaction
having that purpose or effect.

Exhibits:

Exhibit I: Joint Filing Agreement, dated as of April 11, 2006, by and among GLG
Partners LP, GLG Partners Limited, Noam Gottesman, Pierre Lagrange and Emmanuel
Roman.




CUSIP No. 26881Q101                  13G                    Page 11 of 12 Pages


SIGNATURES

            After reasonable inquiry and to the best of its knowledge and
belief, each of the undersigned certifies that the information with respect to
it set forth in this statement is true, complete, and correct.

Dated: April 11, 2006

GLG PARTNERS LIMITED
                                       GLG PARTNERS LP
                                       By: GLG Partners Limited,
/s/ Noam Gottesman                     as its General Partner
-----------------------------
Name: Noam Gottesman
Title: Managing Director



/s/ Victoria Parry                      /s/ Noam Gottesman
-----------------------------           -----------------------------
Name: Victoria Parry                    Name: Noam Gottesman
Title: Senior Legal Counsel             Title: Managing Director


                                        /s/ Victoria Parry
                                        -----------------------------
                                       Name: Victoria Parry
                                       Title: Senior Legal Counsel

PIERRE LAGRANGE                        NOAM GOTTESMAN


/s/ Pierre Lagrange                    /s/ Noam Gottesman
-----------------------------          -----------------------------

EMMANUEL ROMAN


/s/ Emmanuel Roman
-----------------------------




CUSIP No. 26881Q101                   13G                  Page 12 of 12 Pages

                                    EXHIBIT I

                             JOINT FILING AGREEMENT

This will confirm the agreement by and among the undersigned that the Schedule
13G filed with the Securities and Exchange Commission on or about the date
hereof with respect to the beneficial ownership by the undersigned of the Common
Stock, $0.01 par value, of EPIX Pharmaceuticals, Inc., a Delaware corporation,
is being filed, and all amendments thereto will be filed, on behalf of each of
the persons and entities named below in accordance with Rule 13d-1(k) under the
Securities Exchange Act of 1934, as amended. This Agreement may be executed in
two or more counterparts, each of which shall be deemed an original, but all of
which together shall constitute one and the same instrument.

Dated as of April 11, 2006

GLG PARTNERS LIMITED
                                       GLG PARTNERS LP
                                       By: GLG Partners Limited,
/s/ Noam Gottesman                     as its General Partner
-----------------------------
Name: Noam Gottesman
Title: Managing Director



/s/ Victoria Parry                      /s/ Noam Gottesman
-----------------------------           -----------------------------
Name: Victoria Parry                    Name: Noam Gottesman
Title: Senior Legal Counsel             Title: Managing Director


                                        /s/ Victoria Parry
                                        -----------------------------
                                       Name: Victoria Parry
                                       Title: Senior Legal Counsel

PIERRE LAGRANGE                        NOAM GOTTESMAN


/s/ Pierre Lagrange                    /s/ Noam Gottesman
-----------------------------          -----------------------------

EMMANUEL ROMAN


/s/ Emmanuel Roman
-----------------------------