Exhibit 5.1
February 28, 2019
Sierra Oncology, Inc.
c/o 2150 – 885 West Georgia Street
Vancouver, British Columbia, Canada V6C 3E8
Ladies and Gentlemen:
At your request, as counsel to Sierra Oncology, Inc., a Delaware corporation (the “Company”), we have examined the Registration Statement on FormS-8 to be filed by the Company with the Securities and Exchange Commission (the “Commission”) on or about February 28, 2019 (the “Registration Statement”) in connection with the registration under the Securities Act of 1933, as amended (the “Securities Act”), of an aggregate of 2,974,638 shares (the “Shares”) of the Company’s Common Stock, $0.001 par value per share (the “Common Stock”), subject to issuance by the Company upon the exercise or settlement of awards (including any stock option, restricted stock, stock bonus, stock appreciation right, restricted stock unit or award of performance shares) to be granted under the Company’s 2015 Equity Incentive Plan (the “Plan”). At your request, we are providing this letter to express our opinion on the matters set forth below in this letter (“our opinion”).
In connection with our opinion expressed below we have examined originals or copies of the Company’s current certificate of incorporation and bylaws, the Plan, certain corporate proceedings of the Company’s board of directors and stockholders relating to the Registration Statement, and such other agreements, documents, certificates and statements of the Company, its transfer agent and public or governmental officials, as we have deemed advisable, and we have examined such questions of law as we have considered necessary.
In our examination of documents for purposes of this opinion, we have assumed the authenticity and completeness of all documents submitted to us as originals, the genuineness of all signatures on documents reviewed by us, the conformity to originals and the completeness of all documents submitted to us as copies, the legal capacity of all parties executing any documents (other than the Company), and the absence of any undisclosed termination or modification or waiver of any document, the absence of any extrinsic agreements or documents that might change or affect the interpretation or terms of documents, and the due authorization, execution and delivery of all documents by each party thereto other than the Company. We have also assumed that any certificates or instruments representing the Shares, when issued, will be executed by the Company by officers of the Company duly authorized to do so. In rendering our opinion, we have also relied upon a good standing certificate regarding the Company issued by the Delaware Secretary of State and representations and certifications made to us by the Company, including without limitation representations in a management certificate addressed to us of even date herewith that the Company has available a sufficient number of authorized shares of Common Stock that are not currently outstanding or reserved for issuance under other outstanding securities or plans of the Company, to enable the Company to issue and deliver all of the Shares as of the date of this letter.
We render this opinion only with respect to, and we express no opinion herein concerning the application or effect of the laws of any jurisdiction other than, the existing Delaware General Corporation Law (“DGCL”).
