SEC FORM 4

SEC FORM 4 SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

MPM ASSET MANAGEMENT LLC

(Last)

(First)

(Middle)

C/O MPM CAPITAL

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON

02116

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
TCR2 THERAPEUTICS INC. [ TCRR ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
05/22/2023

4. If Amendment, Date of 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

Rule 10b5-1(c) Transaction Indication

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

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	05/22/2023		X⁽¹⁾		178,269	A	$0.74	374,171	D
Common Stock	05/22/2023		S⁽¹⁾		70,170	D	$1.88	304,001	D
Common Stock								3,370,977	I	See Footnote⁽²⁾

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 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: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock Warrant (Right To Buy)	$0.74	05/22/2023		X⁽¹⁾			42,761	12/13/2016	12/12/2026	Common Stock	42,761	$0.00	0	D
Common Stock Warrant (Right to Buy)	$0.74	05/22/2023		X⁽¹⁾			135,508	12/06/2017	12/05/2027	Common Stock	135,508	$0.00	0	D

1. Name and Address of Reporting Person^*

MPM ASSET MANAGEMENT LLC

(Last)

(First)

(Middle)

C/O MPM CAPITAL

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON

02116

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

EVNIN LUKE

(Last)

(First)

(Middle)

C/O MPM CAPITAL

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON

02116

(City)

(State)

(Zip)

Explanation of Responses:

1. On May 22, 2023, MPM Asset Management LLC ("AM LLC") exercised warrants to purchase 178,269 shares of the Issuer's common stock for $0.74 a share. AM LLC paid the exercise price on a cashless basis, resulting in the Issuer's withholding of 70,170 of the warrant shares to satisfy the exercise price and issuing to AM LLC the remaining 108,099 shares.

2. The shares are held as follows: 3,056,272 by MPM BioVentures 2014, L.P. ("BV 2014"), 203,846 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)") and 110,859 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"). MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B) and BV LLC is the manager of AM BV 2014. Luke Evnin is a managing director of BV LLC and disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein.

Remarks:

	/s/ Luke Evnin, member of MPM Asset Management LLC	05/24/2023
	/s/ Luke Evnin	05/24/2023
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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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SEC Form 4 filed by Mpm Asset Management Llc