Summit Therapeutics Reports Financial Results and Operational Progress for the Second Quarter and Six Months Ended 31 July 2019

• Reported Additional Positive Phase 2 Data Showing Ridinilazole Improved Quality of Life and Microbiome Preservation Compared to Standard of Care
• Appointed Key Marketing Hires Focused on Potential US Commercialisation for Ridinilazole
• Conference Call Today at 1:00pm BST / 8:00am EDT

Oxford, UK, and Cambridge, MA, US, 11 October 2019 - Summit Therapeutics plc (NASDAQ: SMMT, AIM: SUMM) today reports its financial results and provides an update on its operational progress for the second quarter and six months ended 31 July 2019.

“It has been a quarter of strong progress across the clinical, scientific and commercial functions as we focus on our key mission of bringing to market our precision antibiotic, ridinilazole, as a potential new front-line treatment for patients with CDI,” said Glyn Edwards, Chief Executive Officer of Summit. “With our landmark designed Phase 3 clinical trials for ridinilazole continuing on schedule, we have taken steps to secure a bright future for Summit as a leader in antibiotic innovation through the appointment of key hires to support the potential commercialisation of this new class antibiotic. Their experience in leading successful antibiotic launches, combined with the compelling clinical and microbiome data generated to date gives us confidence that, if approved, ridinilazole will be well positioned to become the treatment of choice for patients with C. difficile infection.”

Ridinilazole for C. difficile Infection (‘CDI’) Programme

• Ri-CoDIFy Phase 3 landmark clinical trials aim to support adoption of the precision antibiotic ridinilazole as the new standard of care treatment for CDI by:
  1. showing superiority over the current standard of care, vancomycin, using a composite endpoint measuring sustained clinical response;
  2. generating health economic data to help support ridinilazole’s commercial launch, if approved; and
  3. undertaking deep microbiome analysis that aims to show ridinilazole’s preservation of the gut microbiome.

• The Phase 3 clinical programme remains on track for expected reporting of top-line data in the second half of 2021. The trial initiation phase is progressing well with 17 countries open for enrolment (including 9 new countries in August and September), more than half of the 300 planned clinical trial sites opened, and patient enrolment at 73 and accelerating at the end of September 2019.
• Reported new Phase 2 clinical trial data that showed ridinilazole improved patients’ quality of life compared to vancomycin, including demonstrating statistically significant early and longer-term improvements in measurements of physical and mental health. Additional data highlighted mechanistic insights into how ridinilazole preserves the healthy function of the gut microbiome in patients with CDI. These new results were reported at the ID Week Conference held in Washington DC in early October 2019.
• BARDA increased the total value of its award supporting the clinical and regulatory development of ridinilazole to up to $63.7 million in June 2019. Under this award, BARDA exercised a $9.6 million option related to patient enrolment and dosing in the Phase 3 clinical trials, bringing the total committed funding to $53.6 million.
• Expanded commercial team to undertake preparatory activities to support Summit’s strategy of commercialising ridinilazole in the United States, if approved.
  • Appointed Ms Anna Diaz Triola as Vice President, Marketing. Ms Triola has over 20 years industry experience, including working on the marketing strategy of the blockbuster antibiotic Cubicin® at Cubist.
  • Appointed Mr Kevin McDermott as Vice President, Market Access. Mr McDermott joins Summit from Insmed, where he led Global Market Access to Arikayce®, the first antibiotic to receive US FDA approval through the limited population pathway for antibacterial and antifungal drugs (‘LPAD’).

Discuva Platform

SMT-571 for Gonorrhoea

· Presented data at ASM Microbe and STI & HIV World Congress that showed our new class antibiotic SMT-571 had consistently high potency across over 200 clinically relevant strains of Neisseria gonorrhoeae, including numerous multi-drug resistant and extensively-drug resistant strains.

· IND-enabling studies are ongoing, with the development of SMT-571 being supported by an award of up to $4.5 million from CARB-X.

DDS-04 for Enterobacteriaceae

· DDS-04 compound series is a new class of antibiotics in lead optimisation that acts via the novel bacterial target LolCDE with the potential to treat infections caused by the Gram-negative bacteria, Enterobacteriaceae.

· In vivo proof of concept has been demonstrated with a DDS-04 series compound in pneumonia, sepsis and urinary tract infection (‘UTI’). UTI data were presented at ECCMID in April, and data from all three disease models were presented at the ASM/ESCMID Conference held in September.

Financial Highlights

· Cash and cash equivalents at 31 July 2019 of £20.9 million compared to £26.9 million at 31 January 2019.

· Loss for the three months ended 31 July 2019 of £5.2 million compared to a profit of £26.6 million for the three months ended 31 July 2018. The profit recorded in the three months ended 31 July 2018 was driven by an accelerated release of deferred revenues related to a former licence agreement.

This announcement contains inside information for the purposes of Article 7 of EU Regulation 596/2014 (MAR).

Conference Call and Webcast Information

Summit will host a conference call and webcast to review the financial results for the second quarter and six months ended 31 July 2019 today at 1:00pm BST / 8:00am EDT. To participate in the conference call, please dial +44 (0)844 5718 892 (UK and international participants) or +1 631 510 7495 (US local number) and use the confirmation code 4281539. Investors may also access a live audio webcast of the call via the investors section of the Company’s website, www.summitplc.com. A replay of the webcast will be available shortly after the presentation finishes.

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.

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Forward Looking Statements

Any statements in this press release about the Company’s future expectations, plans and prospects, including but not limited to, 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 ability of BARDA or CARB-X to terminate our 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 studies and 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.