Sierra Oncology (SRRA) S-8 Registration of securities for employees

Exhibit 23.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on FormS-8 of our report dated February 28, 2019, relating to the consolidated financial statements of Sierra Oncology, Inc. and subsidiaries (the “Company) appearing in the Annual Report on Form10-K of the Company for the year ended December 31, 2018.

/s/ Deloitte & Touche LLP

Grand Rapids, MI

February 28, 2019