CNST Constellation Pharmaceuticals Inc

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                                                                                   
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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 * Valentine Karen	2. Issuer Name and Ticker or Trading Symbol CONSTELLATION PHARMACEUTICALS INC [ CNST ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                    _____ 10% Owner __X__ Officer (give title below)    _____ Other (specify below) See Remarks
(Last)          (First)          (Middle) C/O CONSTELLATION PHARMACEUTICALS, INC., 215 FIRST STREET, SUITE 200	3. Date of Earliest Transaction (MM/DD/YYYY) 2/10/2020
(Street) CAMBRIDGE, MA 02142 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY) 2/12/2020	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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	2/10/2020		M		1850.00	A	$8.76	1850.00	D
Common Stock	2/10/2020		M		12246.00	A	$11.50	14096.00	D
Common Stock	2/10/2020		S(1)		14096.00	D	$33.51 (2)	0.00	D
Common Stock	2/11/2020		M		8550.00	A	$11.50	8550.00	D
Common Stock	2/11/2020		S(1)		8550.00	D	$35.03 (3)	0.00	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	$8.76	2/10/2020		M			1850.00	(4)	3/6/2029	Common Stock	1850.00	$0.00	28050.00	D
Stock Option (Right to Buy)	$11.50	2/10/2020		M			12246.00	(5)	7/18/2028	Common Stock	12246.00	$0.00	133089.00	D
Stock Option (Right to Buy)	$11.50	2/11/2020		M			8550.00	(5)	7/18/2028	Common Stock	8550.00	$0.00	124539.00	D

Explanation of Responses:
(1)	These trades were made pursuant to a Rule 10b5-1 trading plan.
(2)	This transaction was executed in multiple trades at prices ranging from $32.37 to $35.00. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
(3)	This transaction was executed in multiple trades at prices ranging from $35.00 to $35.10. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
(4)	This option was granted on March 7, 2019, and the shares underlying the option vest in equal quarterly installments through March 7, 2023, subject to continued service.
(5)	This option was granted on July 19, 2018 and is scheduled to vest as to 25% of the shares underlying the option on July 16, 2019, with the remainder vesting in equal quarterly installments through July 16, 2022, subject to continued service.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Valentine Karen C/O CONSTELLATION PHARMACEUTICALS, INC. 215 FIRST STREET, SUITE 200 CAMBRIDGE, MA 02142			See Remarks

Signatures
/s/ Emma Reeve, as Attorney-in-Fact for Karen Valentine		2/13/2020
**Signature of Reporting Person		Date