Definitive Additional Materials

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 14A

(Rule 14a-101)

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

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☐		Definitive Proxy Statement

☒		Definitive Additional Materials

☐		Soliciting Material Pursuant to §240.14a-12

SIERRA ONCOLOGY, INC.

(Name of Registrant as Specified In Its Charter)

N/A

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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*** Exercise Your Right to Vote ***

Important Notice Regarding the Availability of Proxy Materials for the

Stockholder Meeting to Be Held on June 11, 2019.



		SIERRA ONCOLOGY, INC. SIERRA ONCOLOGY, INC. C/O 2150-885 WEST GEORGIA STREET VANCOUVER, BC V6C 3E8 CANADA

Meeting Information

Meeting Type: Annual Meeting

For holders as of: April 15, 2019

Date: June 11, 2019 Time: 10:00 AM PT

Location: Four Seasons Hotel Vancouver

791 West Georgia Street

Vancouver, BC V6C 2T4

Canada

You are receiving this communication because you hold shares in the company named above.

This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side).

We encourage you to access and review all of the important information contained in the proxy materials before voting.

See the reverse side of this notice to obtain proxy materials and voting instructions.

— Before You Vote —

How to Access the Proxy Materials


		Proxy Materials Available to VIEW or RECEIVE:

		NOTICE AND PROXY STATEMENT		FORM 10-K

		How to View Online:

		Have the information that is printed in the box marked by the arrow (located on the following page) and visit: www.proxyvote.com.
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— How To Vote —

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Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card.


		Voting Items


The Board of Directors recommends you vote FOR Proposal 1:

1.	Election of Class I Directors

	Nominees:

	01)	Jeffrey H. Cooper

	02)	Tran Nguyen

The Board of Directors recommends you vote FOR Proposal 2:

2.	To ratify the appointment of Deloitte & Touche LLP as the independent registered public accounting firm for the fiscal year ending December 31, 2019.

NOTE: In their discretion, the proxies are authorized to vote upon such other business as may properly come before the annual meeting or any adjournment thereof.