Sec Form 4 Filing - Sinclair Andrew @ Sierra Oncology, Inc. - 2022-07-01

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 Sinclair Andrew 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., 1820 GATEWAY DR., SUITE 110 3. Date of Earliest Transaction (MM/DD/YY) 07/01/2022 (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, $0.001 par value 07/01/2022 D 1,314,127 D $ 55( 3 ) 0 I See footnotes( 1 )( 2 )

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 Stock Option (Right to Buy) $ 13.868 07/01/2022 D 1,500 ( 6 ) 11/29/2029 Common Stock 1,500 ( 8 ) 0 D( 4 )( 5 ) Stock Option (Right to Buy) $ 13.98 07/01/2022 D 6,874 ( 7 ) 06/09/2030 Common Stock 6,874 ( 8 ) 0 D( 4 )( 5 ) Stock Option (Right to Buy) $ 18.11 07/01/2022 D 6,000 06/08/2022 06/08/2031 Common Stock 6,000 ( 8 ) 0 D( 4 )( 5 ) Series A Warrants (Right to Buy) $ 13.2 07/01/2022 D 871,125 11/13/2019 11/13/2024 Common Stock 871,125 $ 45.98( 9 ) 0 I See footnotes( 1 )( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Sinclair Andrew C/O SIERRA ONCOLOGY, INC. 1820 GATEWAY DR., SUITE 110 SAN MATEO,, CA94404 X Signatures /s/ Andrew Sinclair 07/01/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The securities of Sierra Oncology, Inc. (the "Issuer") are held by Abingworth Bioventures VII, LP ("ABV VII"). Abingworth LLP is the investment manager of ABV VII and has been delegated with all investment and dispositive power over the securities held by ABV VII. Reporting Person is a Partner and Portfolio Manager of Abingworth LLP. ( 2 )An investment committee approves investment and voting decisions by a majority vote, and no individual member has the sole control or voting power over the shares held by ABV VII. From time to time, the investment committee may delegate investment and voting authority over certain securities held by ABV VII to employees of Abingworth LLP subject to the supervision and oversight of the investment committee, including any limits on such authority imposed by the investment committee in its discretion and the right of the investment committee to revoke such authority at any time. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein, if any. ( 3 )Reflects disposition in connection with the consummation of the transactions contemplated by the Agreement and Plan of Merger, dated as of April 12, 2022 (the "Merger Agreement"), between Sierra Oncology Inc. (the "Issuer"), GlaxoSmithKline plc ("GSK"), and Orikum Acquisition Inc. ("Acquisition Sub"). On July 1, 2022, upon the closing of the merger of Acquisition Sub with and into the Issuer (the "Merger") contemplated by the Merger Agreement, each share of common stock of the Issuer, par value $0.001 per share, was cancelled and automatically converted into the right to receive an amount in cash equal to $55.00, without interest and less any applicable withholding taxes. ( 4 )This option was granted to Dr. Andrew Sinclair as director's compensation. Dr. Sinclair is a Partner of Abingworth LLP. Under an agreement between Dr. Sinclair and Abingworth LLP, Dr. Sinclair is deemed to hold the options and any shares of Common Stock issuable upon exercise of the options for the benefit of ABV VII, and must exercise the options solely upon the direction of Abingworth LLP. ( 5 )ABV VII may be deemed the indirect beneficial owner of the option, and Dr. Sinclair may be deemed the indirect beneficial owner of the option through his indirect interest in ABV VII. Abingworth LLP disclaims beneficial ownership of the option except to the extent, if any, of its pecuniary interest therein. This report shall not be deemed an admission that Abingworth LLP, ABV VII, Dr. Sinclair or any other person is the beneficial owner of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. ( 6 )The option vested in equal monthly installments over a period of 12 months commencing on December 29, 2019, and was fully vested at the effective time of the Merger. ( 7 )The option vested as to 8.333% of the total shares monthly, commencing on July 9, 2020, and was fully vested at the effective time of the Merger. ( 8 )Pursuant to the Merger Agreement, at the effective time of the Merger all options that were outstanding and unexercised as of immediately prior to the effective time of the Merger accelerated vesting in full and were cancelled and converted into a right to receive an amount in cash, without interest, equal to the product of (1) the excess, if any, of $55.00 less the exercise price per share of such option, and (2) the number of shares of the Issuer's common stock issuable upon exercise in full of such option. ( 9 )At the effective time of the Merger, each warrant to purchase common stock of the Issuer (the "Series A warrants") that was outstanding as of immediately prior to the effective time of the Merger was cancelled and automatically converted into the right to receive an amount in cash equal to $45.98 per share of the Issuer's common stock subject to the Series A warrants.

Remarks: As of July 1, 2022, the Reporting Person is no longer subject to Section 16 of the Securities Exchange Act of 1934 in connection with transactions in the securities of the Issuer, and therefore will no longer report any such transactions on Form 4 or Form 5.

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.