X0306 4 2020-01-29 0 0001290149 Sierra Oncology, Inc. SRRA 0001551965 Aggarwal Gaurav C/O SIERRA ONCOLOGY, INC. 2150 - 885 WEST GEORGIA STREET VANCOUVER A1 V6C 3E8 BRITISH COLUMBIA, CANADA 1 0 1 0 Common Stock 2020-01-29 4 C 0 1455576 0.00 A 1455576 I By Vivo Opportunity Fund, LP Series A Convertible Voting Preferred Stock 2020-01-29 4 C 0 19213 D Common Stock 1455576 0 I By Vivo Opportunity Fund, LP On January 22, 2020, a 1-for-40 reverse split of the Issuer's Common Stock (the "Reverse Split") was effected. These securities reflect the Reverse Split. Each share of Series A Convertible Voting Preferred Stock (the "Series A Preferred Stock") converted into 75.76 shares of the Issuer's Common Stock, as adjusted for the Reverse Split, automatically upon the 5th trading date following the Issuer's announcement of receiving stockholder approval for the Reverse Split following November 13, 2019. The Series A Preferred Stock has no expiration date. The Reporting Person is a managing member of Vivo Opportunity, LLC, which is the general partner of Vivo Opportunity Fund, L.P. ("VOF"). The Reporting Person may be deemed to share voting and dispositive power over the securities held by VOF 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. Consists of 19,213 shares of Series A Preferred Stock held by VOF which are convertible into an aggregate of 1,455,576 shares of Common Stock, as adjusted for the Reverse Split. /s/ Sukhi Jagpal as attorney-in-fact for Gaurav Aggarwal 2020-01-31