Statement of Changes in Beneficial Ownership (4)

FORM 4 [X] 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
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^* FIER IAN	2. Issuer Name and Ticker or Trading Symbol MOMENTA PHARMACEUTICALS INC [ MNTA ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Mfg and Program Officer
(Last) (First) (Middle) C/O MOMENTA PHARMACEUTICALS, INC., 301 BINNEY STREET	3. Date of Earliest Transaction (MM/DD/YYYY) 10/1/2020
(Street) CAMBRIDGE, MA 02142 (City) (State) (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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. Trans. Date	2A. Deemed Execution Date, if any	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)

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)			11. Nature of Indirect Beneficial Ownership (Instr. 4)
Restricted Stock Units	⁽¹⁾	10/1/2020		D			45000	⁽¹⁾	⁽¹⁾	Common Stock	45000	⁽¹⁾	0	D
Restricted Stock Units	⁽¹⁾	10/1/2020		D			1425	⁽¹⁾	⁽¹⁾	Common Stock	1425	⁽¹⁾	0	D
Restricted Stock Units	⁽¹⁾	10/1/2020		D			21938	⁽¹⁾	⁽¹⁾	Common Stock	21938	⁽¹⁾	0	D
Restricted Stock Units	⁽¹⁾	10/1/2020		D			40000	⁽¹⁾	⁽¹⁾	Common Stock	40000	⁽¹⁾	0	D
Stock Option (Right to Buy)	$18.85	10/1/2020		D			2751	⁽²⁾	2/7/2027	Common Stock	2751	⁽²⁾	0	D
Stock Option (Right to Buy)	$12.76	10/1/2020		D			20192	⁽²⁾	2/11/2029	Common Stock	20192	⁽²⁾	0	D
Stock Option (Right to Buy)	$31.87	10/1/2020		D			3622	⁽²⁾	2/7/2030	Common Stock	3622	⁽²⁾	0	D
Stock Option (Right to Buy)	$18.85	10/1/2020		D			99	⁽²⁾	2/7/2027	Common Stock	99	⁽²⁾	0	D
Stock Option (Right to Buy)	$12.76	10/1/2020		D			52808	⁽²⁾	2/11/2029	Common Stock	52808	⁽²⁾	0	D
Stock Option (Right to Buy)	$31.87	10/1/2020		D			76378	⁽²⁾	2/7/2030	Common Stock	76378	⁽²⁾	0	D

Explanation of Responses:
(1)	Reflects disposition of Issuer restricted stock units in accordance with that certain Agreement and Plan of Merger, dated as of August 19, 2020 (the "Merger Agreement"), by and among Johnson & Johnson, Vigor Sub, Inc. and the Issuer, pursuant to which, effective immediately prior to the effective time of the merger contemplated thereby (the "Effective Time"), each Issuer restricted stock unit held by the Reporting Person became vested in full and, as of the Effective Time, was cancelled and converted into the right to receive an amount in cash (without interest) equal to the product obtained by multiplying (x) the aggregate number of shares of Issuer common stock underlying such Issuer restricted stock unit immediately prior to the Effective Time by (y) $52.50 per share in cash, without interest, less any required withholding taxes (the "Offer Price").
(2)	Reflects disposition of options to acquire shares of Issuer common stock (each, an "Issuer Option") in accordance with the Merger Agreement, pursuant to which, effective immediately prior to the Effective Time, each Issuer Option held by the Reporting Person became vested in full and, as of the Effective Time, was cancelled and converted into the right to receive an amount in cash (without interest) equal to the product obtained by multiplying (x) the aggregate number of shares of Issuer common stock underlying such Issuer Option immediately prior to the Effective Time by (y) the amount, if any, by which the Offer Price exceeds the per share exercise price of such Issuer Option.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
FIER IAN C/O MOMENTA PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE, MA 02142			Chief Mfg and Program Officer