SRRA Sierra Oncology Inc

As previously disclosed, on April 12, 2022, Sierra Oncology, Inc. (the “Company”) entered into an Agreement and Plan of Merger (the “Merger Agreement”) with GlaxoSmithKline plc, a public limited company organized under the laws of England and Wales (“GSK”) and Orikum Acquisition Inc., a Delaware corporation and wholly owned subsidiary of GSK (“Acquisition Sub”). The Merger Agreement provides that, subject to the terms and conditions set forth in the Merger Agreement, Acquisition Sub will merge with and into the Company (the “Merger”), with the Company surviving the Merger as a wholly owned subsidiary of GSK.

Under the terms of the Merger Agreement, the consummation of the Merger is subject to the satisfaction or waiver of customary closing conditions, including the expiration or termination of the waiting period under the United States Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”). Effective as of 11:59 p.m. Eastern Time on May 31, 2022, the waiting period under the HSR Act expired with respect to the Merger.

Consummation of the Merger remains subject to other customary closing conditions, including the approval of the Merger Agreement by holders of a majority of the outstanding shares of the Company’s common stock.

Forward Looking Statements

This communication contains certain statements that constitute forward-looking statements. These forward-looking statements include, but are not limited to, statements regarding the satisfaction of conditions to the closing of the proposed acquisition of the Company by GSK and the expected occurrence and timing of the consummation of the proposed acquisition, as well as other statements that are not historical fact. These forward-looking statements are based on currently available information, as well as the Company’s views and assumptions regarding future events as of the time such statements are being made. Such forward looking statements are subject to inherent risks and uncertainties. Accordingly, actual future events or results may differ from those expressed or implied in such forward-looking statements. Such risks and uncertainties include, but are not limited to, the risk that the conditions to the closing of the proposed acquisition are not satisfied, including the risk that the required approval of the Company’s stockholders is not obtained; potential litigation relating to the proposed acquisition; uncertainties as to the timing of the consummation of the proposed acquisition and the ability of each party to consummate the acquisition; the failure to realize anticipated benefits of the proposed acquisition when expected or at all; potential adverse reactions or changes to business relationships resulting from the proposed acquisition, including the effect of the announcement on the ability of the Company to retain and hire key personnel; risks that the proposed acquisition disrupts the current plans and operations of the Company; and other risks and uncertainties described in cautionary statements contained in the Company’s periodic reports filed with the SEC including the statements set forth under “Risk Factors” set forth in the Company’s most recent annual report on Form 10-K and the proxy statement (the “Proxy Statement”) filed by the Company with the Securities and Exchange Commission (the “SEC”) on May 16, 2022 in connection with the proposed acquisition. While the Company may elect to update any such forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so, even if our expectations change, except as required by law.