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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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^*

Thomson Mary Christina

(Last)

(First)

(Middle)

C/O SIERRA ONCOLOGY, INC.

1820 GATEWAY DR., SUITE 110

(Street)

SAN MATEO

94404

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
Sierra Oncology, Inc. [ SRRA ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
07/01/2022

4. If Amendment, Date of 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

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)

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)
Stock Option (right to buy)	$13.04	07/01/2022		D			92,000	⁽¹⁾	07/28/2030	Common Stock	92,000	$0.00⁽²⁾	0	D
Stock Option (right to buy)	$12.15	07/01/2022		D			49,000	⁽³⁾	08/12/2030	Common Stock	49,000	$0.00⁽²⁾	0	D
Stock Option (right to buy)	$16.73	07/01/2022		D			12,900	⁽⁴⁾	03/15/2031	Common Stock	12,900	$0.00⁽²⁾	0	D
Stock Option (right to buy)	$31.54	07/01/2022		D			35,000	⁽⁵⁾	03/14/2032	Common Stock	35,000	$0.00⁽²⁾	0	D

Explanation of Responses:

1. The option vested as to 25% of the total shares on July 28, 2021, and then the remaining shares vest in equal monthly installments over the following 36 months, with 100% of the total shares vested on July 28, 2024, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

2. Pursuant to the terms of the merger agreement between issuer, GlaxoSmithKline plc ("GSK") and a subsidiary of GSK, this option was cancelled on the effective date of the merger in exchange for a cash payment equal to, on a per share basis, the offer price of $55.00 less the exercise price.

3. On August 12, 2020, the reporting person was granted an option to purchase 49,000 shares of common stock. The option vests based on the satisfaction by Issuer of certain performance criteria.

4. The option vested as to 25% of the total shares subject to the option on March 15, 2022, and then 2.0833% of the shares subject to the option vest monthly thereafter, with 100% of the total shares subject to the option vested on March 15, 2025, subject to Reporting Person's provision of service to the Issuer on each vesting date.

5. The option vests as to 25% of the total shares subject to the option on March 14, 2023, and then 2.0833% of the shares subject to the option vest monthly thereafter, with 100% of the total shares subject to the option vested on March 14, 2026, subject to Reporting Person's provision of service to the Issuer on each vesting date.

Remarks:

	/s/ Mary Christina Thomson	07/01/2022
	** 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.
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 Number.

SEC Form 4 filed by Thomson Mary Christina