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 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 * Reeders Stephen T   2. Issuer Name and Ticker or Trading Symbol MOMENTA PHARMACEUTICALS INC [MNTA] 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 MVM INTERNATIONAL LIFE SCIENCES FUND, NO. 1 L.P. 6 HENRIETTA STREET 3. Date of Earliest Transaction (Month/Day/Year) 02/27/2006 (Street) LONDON, X0 WC2E 8PU 4. If Amendment, Date Original Filed(Month/Day/Year) 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 (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 02/27/2006   S   66 D $ 24.35 5,899 D   Common Stock 03/02/2006   S   7 D $ 24.4 5,892 D   Common Stock 09/06/2006   S   463 D $ 15.26 5,429 D   Common Stock 02/27/2006   S   29,700 D $ 24.35 1,581,150 I (1) See Footnote (2) Common Stock 03/02/2006   S   3,366 D $ 24.4 1,577,784 I See Footnote (2) Common Stock 08/25/2006   S   15,803 D $ 16.5 1,561,981 I See Footnote (2) Common Stock 08/29/2006   S   165,280 D $ 16.5 1,396,701 I See Footnote (2) Common Stock 08/30/2006   S   27,005 D $ 16.53 1,369,696 I See Footnote (2) Common Stock 01/10/2007   J(3)   430,000 D $ 0 939,696 I See Footnote (2) Common Stock 02/27/2006   S   95 D $ 24.35 8,561 I See Footnote (4) Common Stock 03/02/2006   S   10 D $ 24.4 8,551 I See Footnote (4) Common Stock 09/06/2006   S   671 D $ 15.26 7,880 I See Footnote (4)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Reeders Stephen T C/O MVM INTERNATIONAL LIFE SCIENCES FUND NO. 1 L.P. 6 HENRIETTA STREET LONDON, X0 WC2E 8PU	X

Signatures

/s/ Stephen T Reeders		03/28/2007
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Stephen Reeders has in the past reported as indirectly owning shares held by Martin Murphy, David Brister, Paul Triniman, Richard Lim and Thomas Casdagli. However, he does not have and has never had a pecuniary interest in any of the shares owned by these individuals. The indirect ownership interest reported on Dr. Reeders' Form 3 and Form 4s was reported in the past in error.
(2)	These shares are held directly by MVM International Life Sciences Fund No. 1 L.P. Stephen Reeders is an investment manager of MVM Life Science Partners LLP and exercises discretionary investment power over securities held by MVM International Life Sciences Fund No. 1 L.P. Dr. Reeders disclaims beneficial ownership of these shares except to the extent of his proportionate pecuniary interest in such shares.
(3)	Pro rata distribution from MVM International Life Sciences Fund No. 1 L.P. to its limited partners.
(4)	These shares are held directly by MVM Limited. Stephen Reeders is an investment manager of MVM Life Science Partners LLP and exercises discretionary investment power over securities held by MVM Limited. Dr. Reeders disclaims beneficial ownership of these shares except to the extent of his proportionate pecuniary interest in such shares.

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