Summit’s SMT-571 Potent Against Over 200 Clinical Isolates of Neisseria Gonorrhoeae, Including Numerous Multi- and Extensively-Drug Resistant Strains, in Published Preclinical Data

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

Summit’s SMT-571 Potent Against Over 200 Clinical Isolates of Neisseria Gonorrhoeae, Including Numerous Multi- and Extensively-Drug Resistant Strains, in Published Preclinical Data

• Data Highlight SMT-571’s Potential to Address Global Gonorrhoea Threat

Oxford, UK, and Cambridge, MA, US, 25 February 2019 – Summit Therapeutics plc (NASDAQ: SMMT, AIM: SUMM), a leader in new mechanism antibiotic innovation, published preclinical data on SMT-571, a new mechanism antibiotic in development for the treatment of gonorrhoea, in collaboration with the Örebro University in Sweden. In the published data, SMT-571 was found to be potent against diverse, global Neisseria gonorrhoeae strains from actual patient cases, including numerous multi- and extensively-drug resistant strains.

“Neisseria gonorrhoeae continues to evolve and acquire resistance to every marketed antibiotic with which it has been challenged. The concern of practitioners is once 5% resistance to the current standard of care is reached, there will be no new treatments available for gonorrhoea,” said Professor Magnus Unemo, of Örebro University, a WHO Collaborating Centre for Gonorrhoea and Other Sexually Transmitted Infections, and senior author of the paper. “Antibiotics with a new mechanism of action will be important in addressing the global health threat of gonorrhoea. In the published data, we demonstrated that SMT-571, a new mechanism antibiotic, had consistently high potency across hundreds of relevant clinical strains of N. gonorrhoeae, including those that are multi- and extensively-drug resistant. I look forward to the continued development of SMT-571.”

The paper, “In vitro activity of the novel oral antimicrobial SMT-571, with a new mechanism of action, against MDR and XDR Neisseria gonorrhoeae: future treatment option for gonorrhoea?,” was published in the Journal of Antimicrobial Chemotherapy and authored by C. Mason, N. Khan and P. Meo of Summit and S. Jacobsson and M. Unemo of Örebro University. In the study, researchers tested SMT-571 against 228 clinical isolates and 34 international gonococcal reference strains. SMT-571 achieved potent activity with minimum inhibitory concentrations of 0.064 to 0.125 mg/L against all tested strains. Importantly, SMT-571 did not show cross-resistance with any antimicrobials currently or previously used for the treatment of gonorrhoea. These data further expand the range of N. gonorrhoeae strains against which SMT-571 has shown activity, indicating SMT-571 is a promising new mechanism antibiotic in development for the treatment of gonorrhoea.

About SMT-571
SMT-571 is a small molecule, novel mechanism 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 gonorrhea 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- and extensively-drug resistant ones. 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 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 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 ESKAPE pathogens 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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