Timetable Update

Summit Therapeutics plc
(“Summit Therapeutics” or the “Company”)

Timetable update for the proposed Subscription and Placing

Oxford, UK, and Cambridge, MA, US, 19 December 2019 - Summit Therapeutics plc (AIM: SUMM, NASDAQ: SMMT), a leader in antibiotic innovation, announces that, further to the announcement made on 6 December 2019 regarding a fundraising of approximately $50 million through a subscription and placing of new ordinary shares and warrants to existing investors, the expected date of Admission and commencement of dealings in the New Ordinary Shares on AIM has been changed from 8.00 a.m. on 30 December 2019 to 8.00 a.m. 24 December 2019.

The Fundraising requires approval by Shareholders at the General Meeting of the Company to be held on 23 December 2019. A further announcement will be made following the conclusion of that meeting.

Capitalised terms in this announcement have the same meanings as in the Circular issued by the Company on 6 December 2019.

This announcement contains inside information for the purposes of Article 7 of EU Regulation 596/2014. The person responsible for arranging for the release of this announcement on behalf of the Company is Richard Pye, Vice President, Investor Relations and Corporate Affairs.

About Summit Therapeutics
Summit Therapeutics is a leader in antibiotic innovation. Our new mechanism antibiotics are designed to become the new standards of care for the benefit of patients and create value for payors and healthcare providers. We are currently developing new mechanism antibiotics to treat infections caused by C. difficile, N. gonorrhoeae and Enterobacteriaceae and are using our proprietary Discuva Platform to expand our pipeline. For more information, visit www.summitplc.com and follow us on Twitter @summitplc.

For more information, please contact:

Forward Looking Statements
Any statements in this press release about the Company’s future expectations, plans and prospects, including but not limited to, whether or not the Company will consummate the Fundraising, the restructuring of the board of directors, the AIM Delisting, the trading markets for the Company's ordinary shares and ADSs, statements about the potential benefits and future operation of the BARDA or CARB-X contract, including any potential future payments thereunder, the clinical and preclinical development of the Company’s product candidates, the therapeutic potential of the Company’s product candidates, the potential of the Discuva Platform, the potential commercialisation of the Company’s product candidates, the sufficiency of the Company’s cash resources, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: the risk that the Company's shareholders do not approve the Fundraising and AIM Delisting, the risk that other closing conditions to the Fundraising are not satisfied, the ability of BARDA or CARB-X to terminate the Company’s contract for convenience at any time, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future preclinical studies and clinical trials and the results of such preclinical studies and clinical trials, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, expectations for regulatory approvals, laws and regulations affecting government contracts, availability of funding sufficient for the Company’s foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" section of filings that the Company makes with the Securities and Exchange Commission, including the Company’s Annual Report on Form 20-F for the fiscal year ended 31 January 2019. Accordingly, readers should not place undue reliance on forward-looking statements or information. In addition, any forward-looking statements included in this press release represent the Company’s views only as of the date of this release and should not be relied upon as representing the Company’s views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this press release.

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