Mona Ashiya - Jun 8, 2021 Form 4 Insider Report for Sierra Oncology, Inc. (SRRA)

Role: Director, 10%+ Owner
Signature: /s/ Mona Ashiya; By: Mary Christina Thomson, Attorney-In-Fact
Stock symbol: SRRA
Transactions as of: Jun 8, 2021
Transactions value $: $0
Form type: 4
Date filed: 6/9/2021, 10:36 AM
Next filing: Jan 28, 2022

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	SRRA	Stock Option (Right To Buy)	Award	$0	+6K		$0.00	6K	Jun 8, 2021	Common Stock	6K	$18.11	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The Option fully vests and becomes exercisable on June 8, 2022, subject to the Reporting Person's provision of service to the Issuer as of the vesting date.
F2	Pursuant to an agreement with OrbiMed Advisors LLC and OrbiMed Capital GP VII LLC, the Reporting Person is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to OrbiMed Advisors LLC and OrbiMed Capital GP VII LLC, which will in turn ensure that such securities or economic benefits are provided to OrbiMed Private Investments VII, LP.

Content

The Option fully vests and becomes exercisable on June 8, 2022, subject to the Reporting Person's provision of service to the Issuer as of the vesting date.

Pursuant to an agreement with OrbiMed Advisors LLC and OrbiMed Capital GP VII LLC, the Reporting Person is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to OrbiMed Advisors LLC and OrbiMed Capital GP VII LLC, which will in turn ensure that such securities or economic benefits are provided to OrbiMed Private Investments VII, LP.