Summit Therapeutics Presents Further Breakthrough Insights Surrounding the Novel Mechanism of Action for its Investigational Drug Ridinilazole During IDWeek 2021

Cambridge, Massachusetts, Sept. 30, 2021 (GLOBE NEWSWIRE) — Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit” or the “Company”) is today displaying an important ePoster at IDWeek 2021. IDWeek is the joint annual meeting of the Infectious Diseases Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), the HIV Medical Association (HIVMA), the Pediatric Infectious Diseases Society (PIDS), and the Society of Infectious Diseases Pharmacists (SIDP). Summit’s ePoster provides enhanced details regarding the newly discovered novel mechanism of action of ridinilazole. The ePoster will be available throughout IDWeek 2021, which takes place between September 29 and October 3, 2021.

Ridinilazole is Summit Therapeutics’ investigational first-in-class drug that recently completed enrollment of a Phase III clinical trial, Ri-CoDIFy. The primary endpoint of this trial seeks to demonstrate the superiority of ridinilazole in sustained clinical response as compared to vancomycin. Ridinilazole is not currently approved for use by any regulatory authority.

Summit’s poster presentation provides demonstrable scientific evidence of ridinilazole’s novel mechanism of action which involves binding to the minor groove of Clostridioides difficile bacteria’s DNA (the minor groove is a location on the helix of the bacteria’s DNA to which a drug can attach or bind). This is believed to be the primary mechanism through which ridinilazole elicits its bactericidal action against C. difficile bacteria. Ridinilazole has a novel mechanism of action and is the first of a new class of antibiotics:  this is consistent with the World Health Organization’s (WHO) recommendation for developing antibiotics with novel mechanisms of action or that are new classes of drugs, which it considers a key point in overcoming existing bacterial resistance.¹

Our updated research, through collaboration with the University of Houston, provides new images from high-resolution confocal microscopy. This technique has allowed intracellular visualization of ridinilazole binding to DNA within C. difficile and confirms this novel mechanism of action. Ridinilazole, if approved, has the potential to be the first antibiotic with a novel mechanism of action approved in over ten years.

The poster is available within the “Scientific Literature & Publications” section of our website: https://www.summittxinc.com/publications/.

About Summit Therapeutics

The overriding objective of Summit Therapeutics is to create value for patients, hospital caregivers, and community-based healthcare providers, as well as healthcare payers around the world. We seek to create value by developing drugs with high therapeutic efficacy – curing the cause of the patient’s condition with minimal or zero disease recurrence or antimicrobial resistance, for the longest extent possible – and minimizing the trauma caused to the patient and healthcare ecosystem by minimizing serious side effects, disease recurrence, and inaccessibility to our treatments as a result of financial or other barriers. Summit Therapeutics, empowered by its Discuva Platform, the Company’s innovative antibiotic discovery engine, and supported by BARDA and CARB-X funding, intends to be the leader in patient-friendly and paradigm-shifting treatments for infectious diseases and other significant unmet medical needs while being an ally to physicians. Our new mechanism pipeline product candidates are designed with the goal to become the patient-friendly, new-era standard of care, by working in harmony with the human microbiome to treat prospective patients suffering from infectious diseases, initially focusing on Clostridioides difficile infection (CDI). Currently, Summit’s lead product candidate, ridinilazole, is a novel, first-in-class drug engaged in a global Phase III trial program versus vancomycin, for use as first-line therapy for the treatment of initial and recurrent Clostridioides difficile infection, and to show superiority in sustained clinical response. Commercialization of ridinilazole is subject to regulatory approvals. SMT-738, the second candidate within Summit’s portfolio, is currently in the IND-enabling phase for the treatment of multidrug resistant infections, specifically those caused by carbapenem-resistant Enterobacteriaceae (CRE).

For more information, please visit https://www.summittxinc.com and follow us on Twitter @summitplc. For more information on the Company’s Discuva Platform, please visit https://www.summittxinc.com/our-science/discuva-platform.

About C. difficile Infection

Clostridioides difficile, or C. difficile, infection (CDI) is a bacterial infection of the colon that produces toxins causing inflammation of the colon, severe watery diarrhea, painful abdominal cramping, nausea, fever, and dehydration. CDI can also result in more serious disease complications, including bowel perforation, sepsis, and death. CDI is a contagious infectious disease that represents a serious healthcare issue in hospitals, long-term care facilities, and the wider community. Summit estimates that there are approximately 500,000 cases of CDI each year across the United States with acute care costs exceeding $5.4 billion in the US based on a meta-analysis published in the Journal of Global Health, June 2019.

Contact Summit Investor Relations

Dave Gancarz
Head of Investor Relations & Corporate Strategy
david.gancarz@summitplc.com

General Inquiries:
investors@summitplc.com

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 commercialization of the Company’s product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals, the impact of the COVID-19 pandemic on the Company’s operations and clinical trials 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, global public health crises, including the coronavirus COVID-19 outbreak, that may affect timing and status of our clinical trials and operations, 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. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ridinilazole. 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.

¹ https://cdn.who.int/media/docs/default-source/antimicrobial-resistance/amr-gcp-irc/five-key-points-to-consider-for-the-development-and-optimal-use-of-new-antibiotics.pdf?sfvrsn=c4a77671_5