Sec Form 4 Filing - Aggarwal Gaurav @ Sierra Oncology, Inc. - 2022-01-26

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 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

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Aggarwal Gaurav 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) C/O SIERRA ONCOLOGY, INC., 1820 GATEWAY DRIVE, SUITE 110 3. Date of Earliest Transaction (MM/DD/YY) 01/26/2022 (Street) SAN MATEO, CA94404 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 01/26/2022 X 480,277 A $ 13.2 1,935,853 I By Vivo Opportunity Fund, L.P.( 1 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 B Warrant (Right to Purchase) $ 13.2 01/26/2022 X 1,455,384 01/22/2020 ( 2 ) Common Stock 480,277 $ 13.2 0 I By Vivo Opportunity Fund, L.P.( 1 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Aggarwal Gaurav C/O SIERRA ONCOLOGY, INC. 1820 GATEWAY DRIVE, SUITE 110 SAN MATEO, CA94404 X X Signatures /s/ Sukhi Jagpal as attorney-in-fact for Gaurav Aggarwal 01/28/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The Reporting Person is a managing member of Vivo Opportunity, LLC, which is the general partner of Vivo Opportunity Fund, L.P. The Reporting Person may be deemed to share voting and dispositive power over the securities held by Vivo Opportunity Fund, L.P. with four other managing members of Vivo Opportunity, LLC. The Reporting Person disclaims beneficial ownership over such securities except to the extent of his pecuniary interest therein, and the inclusion of such securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purposes. ( 2 )The expiration date of the warrants is the date on the seventy-fifth (75th) day anniversary of the announcement by Issuer, via publicly disseminated press release or SEC filing, of the top-line data results from MOMENTUM, its Phase 3 clinical trial of momelotinib for patients with myelofibrosis.

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.