Summit Therapeutics plc 
(‘Summit’ or the ‘Company’)

Summit Highlighted Potential of SMT-571 to Combat the Rising Global Health Threat of Gonorrhoea at STI & HIV World Congress

Oxford, UK, and Cambridge, MA, US, 17 July 2019 – Summit Therapeutics plc (NASDAQ: SMMT, AIM: SUMM) today announced that it highlighted the potential of its preclinical new class antibiotic, SMT-571, to treat all gonorrhoea, including multi-drug and extensively-drug resistant strains, in a poster presentation at the STI & HIV World Congress in Vancouver, Canada.

“The problem of gonorrhoea resistance is very concerning, and if nothing is done, physicians could see more and more cases of untreatable disease,” said Dr David Roblin, President of R&D of Summit. “As shown by the preclinical data presented, our gonorrhoea-targeted new class antibiotic, SMT-571, has the potential to overcome known resistance mechanisms across global isolates, including multi- and extensively-drug resistant strains. Further, there is a clear need for new gonorrhoea treatment options that would allow ceftriaxone to be reserved for the multitude of other serious infections that rely on its potency.”

Infections caused by the bacteria Neisseria gonorrhoeae are a growing global healthcare problem, with an estimated 78 million new cases globally per year. Infection rates continue to rise sharply as highlighted by the Centers for Disease Control and Prevention (‘CDC’), which reported a 19% increase in US gonorrhoea cases in 2017, and Public Health England, which reported a 26% increase in the UK in 2018. Of great concern is the increase in resistance towards the current standard of care treatment for gonorrhoea, a combination of the broad-spectrum antibiotics, azithromycin and ceftriaxone. N. gonorrhoeae resistance rates to azithromycin are 4.4% and rising, and there is an emergence of resistance to ceftriaxone in these same strains, which are referred to as cases of ‘super gonorrhoea.’

Summit’s poster featured preclinical data showing SMT-571 to be highly potent against 262 clinical strains of N. gonorrhoeae. This comprehensive panel of gonorrhoea strains, obtained from 1991 to 2018, was selected to be geographically and genetically diverse and include strains that are multi- and extensively-drug resistant. SMT-571 had a minimum inhibitory concentration range of 0.064 mg/L to 0.125 mg/L against the strains, including those with reduced susceptibility to ceftriaxone. Significantly, SMT-571 did not show cross-resistance with any antibiotic currently or previously used to treat gonorrhoea infections.

A copy of the poster is available on the Company’s website: www.summitplc.com.

About Gonorrhoea
It is estimated by the World Health Organization (‘WHO’) that there are approximately 78 million new cases of gonorrhoea globally per year. Neisseria gonorrhoeae has consistently developed resistance to each class of antibiotics recommended for treatment and there is now only one treatment recommended by the CDC and European evidence-based guidelines, a combination of two antibiotics. There are currently no other recommended antibiotics that can be effectively deployed to target the disease. The WHO ranks as “high” the priority of R&D investment into the search for antibiotics which are effective against N. gonorrhoeae and in August 2018, the CDC stated that in light of increased problems with resistance, additional treatment options were urgently required.

About SMT-571
SMT-571 is a small molecule, new class antibiotic in preclinical development for the treatment of gonorrhoea. SMT-571 is designed to be an oral treatment with potential activity across the three sites of gonorrhoea infection: urogenital, rectal and pharyngeal. Preclinical studies have shown SMT-571 to have potent activity across a wide range of N. gonorrhoeae strains, including multi-drug and extensively-drug resistant isolates. SMT-571 was identified using Summit’s Discuva Platform, which can identify novel targets, elucidate mechanisms of action and optimise against bacterial resistance.

The development of SMT-571 is supported by the Cooperative Agreement Number IDSEP160030 from ASPR/BARDA and by an award from Wellcome Trust, as administered by CARB-X. The content of this announcement is solely the responsibility of the authors and does not necessarily represent the official views of the Department of Health and Human Services Office of the Assistant Secretary for Preparedness and Response, other funders, or CARB-X.

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 for 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.

Contacts

Summit    
Glyn Edwards / Richard Pye (UK office) Tel: 44 (0)1235 443 951
Michelle Avery (US office)   +1 617 225 4455
     
Cairn Financial Advisers LLP (Nominated Adviser) Tel: +44 (0)20 7213 0880
Liam Murray / Tony Rawlinson    
     
N+1 Singer (Joint Broker) Tel: +44 (0)20 7496 3000
Aubrey Powell / Jen Boorer, Corporate Finance
Tom Salvesen, Corporate Broking
   
     
Bryan Garnier & Co Limited (Joint Broker) Tel: +44 (0)20 7332 2500
Phil Walker / Dominic Wilson

 
   
MSL Group (US) Tel: +1 781 684 6557
Jon Siegal   summit@mslgroup.com
     
Consilium Strategic Communications (UK) Tel: +44 (0)20 3709 5700
Mary-Jane Elliott / Sue Stuart / Sukaina Virji   summit@consilium-comms.com
Lindsey Neville    

Summit 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 clinical and preclinical development of the Company’s product candidates, the therapeutic potential of the Company’s product candidates, 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 uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials and the results of such 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 and funding awards, 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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