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Summit Therapeutics to Present Ri-CoDIFy Trial Results for Microbiome-Sparing Ridinilazole at IDWeek 2022

Menlo Park, California, October 13, 2022 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) and its product candidate, ridinilazole, will have an oral podium presentation and a poster presentation at IDWeek 2022. IDWeek is the joint annual meeting of the Infectious Diseases Society of America (IDSA), the Society for Healthcare Epidemiology of America (SHEA), the HIV Medicine Association (HIVMA), the Pediatric Infectious Diseases Society (PIDS), and the Society of Infectious Diseases Pharmacists (SIDP).

The oral presentation, entitled “Ri-CoDIFy – A Phase 3, Randomized, Double-Blind Study to Evaluate the Efficacy and Safety of Ridinilazole Compared with Vancomycin for the Treatment of Clostridioides difficile Infection” will provide details of the results of the Ri-CoDIFy trial for our investigational, first-in-class antibiotic, ridinilazole, for the treatment of Clostridioides difficile infection (“C. diff. infection,” or “CDI”).

In the Ri-CoDIFy study, ridinilazole resulted in a meaningful reduction in the rate of recurrence of C. diff. infection (8.1% vs 17.3%) and achieved a numerically higher sustained clinical response rate (73.0% vs 70.7%) than vancomycin.

In The Journal of Infectious Diseases (Jul 2021), Drs. Maria Y. Giovanni, Johanna S. Schneider, Thomas Calder, and Anthony S. Fauci noted:
Now is the time to refocus microbiota research beyond association studies and advance research on the mechanisms that underly the causal links between the human microbiota and infectious and immune-mediated diseases. … Commensal [co-existing] organisms influence susceptibility to infection by protecting against invasion, maintaining their own colonization, and resisting subsequent colonization by pathogens. … The importance of a healthy gut microbiota is made evident by the effects of antibiotics, which can wreak havoc by altering the composition and diversity of the gut microbiota and disrupt the ability to prevent colonization by pathogens. Antibiotics can increase susceptibility to bacterial enteric infections, including infections with Clostridium difficile…. In addition, reduced bacterial diversity of the human gut microbiota is associated with COVID-19 infection.

Consistent with the premise from Dr. Giovanni, et. al., which included Dr. Fauci as the senior author, higher microbiome diversity was associated with a lower CDI recurrence rate in the Ri-CoDIFy study. This will be the first in-depth presentation of the large and comprehensive assessment of the microbiome-sparing effects of ridinilazole as compared to the effects of vancomycin when treating patients with C. diff. infection. We are pleased to inform that the results of our clinical study validated the assertions of Drs. Giovanni, Schneider, Calder, and Fauci.

The poster, entitled “A US-Based National Surveillance Study for the Susceptibility and Epidemiology of Clostridioides difficile Associated Diarrheal Isolates with Special Reference to Ridinilazole: 2020-2021” will be available throughout IDWeek 2022, which takes place between October 19-23, 2022.

Ridinilazole is not currently approved for use by any regulatory authority.

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