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
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(Print or Type Responses)
1. Name and Address of Reporting Person *
ORBIMED ADVISORS LLC
  2. Issuer Name and Ticker or Trading Symbol
Sierra Oncology, Inc. [SRRA] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
601 LEXINGTON AVE., 54TH FLOOR		 3. Date of Earliest Transaction (Month/Day/Year)
07/01/2022
(Street)

NEW YORK, NY 10022		 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)
Code V Amount (A) or (D) Price
Common Stock 07/01/2022   D   1,511,362 D $ 55 0 I See footnotes (1) (2)
Common Stock 07/01/2022   D   226,704 D $ 55 0 I See footnotes (2) (3)
Common Stock 07/01/2022   D   226,704 D $ 55 0 I See footnotes (2) (4)

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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 V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series A Warrants $ 13.2 07/01/2022   D     1,136,250 11/13/2019 11/13/2024 Common Stock 1,136,250 $ 0 (5) 0 I See footnotes (1) (2)
Series A Warrants $ 13.2 07/01/2022   D     170,437 11/13/2019 11/13/2024 Common Stock 170,437 $ 0 (5) 0 I See footnotes (2) (3)
Series A Warrants $ 13.2 07/01/2022   D     170,437 11/13/2019 11/13/2024 Common Stock 170,437 $ 0 (5) 0 I See footnotes (2) (4)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ORBIMED ADVISORS LLC
601 LEXINGTON AVE., 54TH FLOOR
NEW YORK, NY 10022		   X   X    
ORBIMED CAPITAL LLC
601 LEXINGTON AVE., 54TH FLOOR
NEW YORK, NY 10022		   X   X    
OrbiMed Genesis GP LLC
601 LEXINGTON AVE., 54TH FLOOR
NEW YORK, NY 10022		   X   X    
OrbiMed Capital GP VII LLC
601 LEXINGTON AVE., 54TH FLOOR
NEW YORK, NY 10022		   X   X    

Signatures

 OrbiMed Advisors LLC; By /s/Douglas Coon, Chief Compl Ofcr.   07/01/2022
**Signature of Reporting Person Date

 OrbiMed Capital LLC; By /s/Douglas Coon, Chief Compl Ofcr.   07/01/2022
**Signature of Reporting Person Date

 OrbiMed Genesis GP LLC; By /s/Douglas Coon, Chief Compl Ofcr.   07/01/2022
**Signature of Reporting Person Date

 OrbiMed Capital GP VII; By /s/Douglas Coon, Chief Compl Ofcr   07/01/2022
**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) These securities are held of record by OrbiMed Private Investments VII, LP ("OPI VII"). OrbiMed Capital GP VII LLC ("GP VII") is the general partner of OPI VII and OrbiMed Advisors LLC ("OrbiMed Advisors") is the managing member of GP VII. By virtue of such relationships, GP VII and OrbiMed Advisors may be deemed to have voting power and investment power over the securities held by OPI VII and as a result, may be deemed to have beneficial ownership over such securities. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPI VII.
(2) This report on Form 4 is jointly filed by OrbiMed Advisors, GP VII, Genesis GP, and OrbiMed Capital. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for purpose of Section 16 of the Exchange Act, or for any other purpose.
(3) These securities are held of record by OrbiMed Genesis Master Fund, L.P. ("Genesis"). OrbiMed Genesis GP LLC ("Genesis GP") is the general partner of Genesis and OrbiMed Advisors is the managing member of Genesis GP. By virtue of such relationships, Genesis GP and OrbiMed Advisors may be deemed to have voting power and investment power over the securities held by Genesis and as a result, may be deemed to have beneficial ownership over such securities. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by Genesis.
(4) These securities are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital LLC ("OrbiMed Capital") is the investment advisor to OPM. OrbiMed Capital is a relying advisor of OrbiMed Advisors. OrbiMed Advisors and OrbiMed Capital exercise voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPM.
(5) Pursuant to the terms of the merger agreement between issuer, GlaxoSmithKline plc ("GSK") and a subsidiary of GSK (the "Merger"), the Company's outstanding warrants will be treated in accordance with their respective terms. At the effective time of the Merger, any of the Company's outstanding Series A warrants will be cancelled and represent only the right to receive an amount in cash, without interest, equal to the Black Scholes Value (as defined in the Series A Warrants) which is calculated under the terms of the Series A warrants to be $45.98 per share of our common stock subject to the Series A warrants.

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