Edgar Filing: MOMENTA PHARMACEUTICALS INC

Ownership Submission

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

OMB APPROVAL

OMB Number:

3235-0287

Expires:

January 31, 2005

Estimated average burden hours per response...

0.5

(Print or Type Responses)

1. Name and Address of Reporting Person ^*

POLARIS VENTURE MANAGEMENT CO III LLC

2. Issuer Name and Ticker or Trading Symbol
MOMENTA PHARMACEUTICALS INC [MNTA]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

_____ Director	__X__ 10% Owner
_____ Officer (give title below)	_____ Other (specify below)

(Last)

(First)

(Middle)

1000 WINTER STREET, SUITE 3350

3. Date of Earliest Transaction (Month/Day/Year)
06/27/2005

(Street)

WALTHAM, MA 02451-1215

4. If Amendment, Date 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

(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)
1.Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	06/27/2005		J⁽¹⁾		2,879,734	D	⁽³⁾	1,743,132	I ⁽⁴⁾	by Polaris Venture Partners III, L.P.
Common Stock	06/27/2005		J⁽²⁾		74,840	D	⁽³⁾	45,301	I ⁽⁴⁾	by Polaris Venture Partners Entrepreneurs' Fund III, L.P.
Common Stock	06/27/2005		J⁽⁵⁾		45,426	D	⁽³⁾	27,497	I ⁽⁴⁾	by Polaris Venture Partners Founders' Fund III, L.P.
Common Stock	06/27/2005		J⁽⁵⁾		450	A	⁽³⁾	1,816,380	D ⁽⁴⁾
Common Stock	06/27/2005		J⁽⁵⁾		365 ⁽⁶⁾	A	⁽³⁾	1,816,745	D ⁽⁴⁾
Common Stock	06/27/2005		J⁽²⁾		369 ⁽⁷⁾	A	⁽³⁾	1,816,749	D ⁽⁴⁾

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

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

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
POLARIS VENTURE MANAGEMENT CO III LLC 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X
POLARIS VENTURE PARTNERS III LP 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X
POLARIS VENTURE PARTNERS FOUNDERS FUND III LP 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X
POLARIS VENTURE PARTNERS ENTREPRENEURS FUND III LP 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X
Arnold Stephen D 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X
Flint Jonathan A 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X
MCGUIRE TERRANCE 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X
SPOON ALAN G 1000 WINTER STREET SUITE 3350 WALTHAM, MA 02451-1215		X

Signatures

/s/ Kevin Littlejohn, Authorized Signatory		06/29/2005
^**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)	Pro-rata distribution in kind without consideration to the general and limited partners of Polaris Venture Partners III, L.P. , a partnership ("PVP III") of which the Designated Filer, Polaris Venture Management Co. III, L.L.C. ("PVM III"), is the general partner. PVM III disclaims beneficial ownership of shares held by PVP III except to the extent of any pecuniary interest therein.
(2)	Pro-rata distribution in kind without consideration to the general and limited partners of Polaris Venture Partners Entrepreneurs' Fund III, L.P., a partnership ("PVPEF III") of which the Designated Filer, PVM III, is the general partner. PVM III disclaims beneficial ownership of shares held by PVPEF III except to the extent of any pecuniary interest therein.
(3)	N/A
(4)	Jonathan A. Flint, Terrance G. McGuire, Alan G. Spoon and Stephen D. Arnold, the managing members of the Designated Filer, PVM III, may be deemed to share voting and dispositive power over shares held by PVM III. Such persons disclaim beneficial ownership of shares held by PVM III except to the extent of any indirect pecuniary interest therein.
(5)	Pro-rata distribution in kind without consideration to the general and limited partners of Polaris Venture Partners Founders' Fund III, L.P., a partnership ("PVPFF III") of which PVM III is the general partner. PVM III disclaims beneficial ownership of shares held by PVPFF III except to the extent of any pecuniary interest therein.
(6)	These shares are owned directly by Stephen D. Arnold.
(7)	These shares are owned directly by Jonathan A. Flint.

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

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.