Sec Form 4 Filing - Parfet Donald R @ Sierra Oncology, Inc. - 2018-01-04

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

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1. Name and Address of Reporting Person Parfet Donald R 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 _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O SIERRA ONCOLOGY, INC., 2150 885 WEST GEORGIA ST. 3. Date of Earliest Transaction (MM/DD/YY) 01/04/2018 (Street) VANCOUVER, A1V6C 3E8 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 01/04/2018 J( 1 ) 3,383 A $ 0 390,913 I By Donald R. Parfet 2006 Trust, Dated May 1, 2006 ( 2 ) Common Stock 01/04/2018 J( 1 ) 1,692 A $ 0 1,692 I Apjohn Ventures, LLC ( 3 ) Common Stock 01/04/2018 J( 4 ) 1,068 A $ 0 2,760 I Apjohn Ventures, LLC ( 3 ) Common Stock 01/04/2018 J( 5 ) V 2,760 D $ 0 0 I Apjohn Ventures, LLC ( 3 ) Common Stock 01/04/2018 J( 6 ) V 1,380 A $ 0 77,235 D Common Stock 238,419 I By Ann VanDeWater Parfet 2006 Revocable Trust, Dated May 5, 2006 ( 7 ) Common Stock 4,970 I By wife Common Stock 589 I By Apjohn Group, LLC ( 8 )

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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Parfet Donald R C/O SIERRA ONCOLOGY, INC. 2150 885 WEST GEORGIA ST. VANCOUVER, A1V6C 3E8 X Signatures /s/ Sukhi Jagpal as attorney-in-fact for Donald Parfet 01/05/2018 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents shares of the issuer's common stock received in connection with a pro rata distribution of shares held by Apjohn Ventures Fund, LP to its limited partners. ( 2 )The reporting person is the trustee of the Donald R. Parfet 2006 Trust, Dated May 1, 2006. ( 3 )The reporting person is a managing member of Apjohn Ventures, LLC ("AVLLC"), and has shared voting and shared dispositive power over the shares held by AVLLC. The reporting person disclaims beneficial ownership over such securities except to the extent of his pecuniary interest therein, and the inclusion of these 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. ( 4 )Represents shares of the issuer's common stock received in connection with a pro rata distribution of shares held by Apjohn Ventures Annex Fund LP to its limited partners. ( 5 )Represents a pro rata distribution of shares of the issuer's common stock held by AVLLC to its members. ( 6 )Represents shares of the issuer's common stock received in connection with a pro rata distribution of shares held by AVLLC to its members. ( 7 )The reporting person's wife is the trustee of the Ann VanDeWater Parfet 2006 Revocable Trust, Dated May 5, 2006. The reporting person disclaims beneficial ownership of such securities, and the inclusion of these 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. ( 8 )The reporting person is the managing member of Apjohn Group, LLC ("AGLLC"), and has sole voting and dispositive power over the shares held by AGLLC. The reporting person disclaims beneficial ownership over such securities except to the extent of his pecuniary interest therein, and the inclusion of these 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.

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).

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