Summit Therapeutics announces topline results for phase III Ri-CoDIFy study for C. Difficile infection.

The study showed that ridinilazole resulted in a higher observed SCR rate than vancomycin but did not meet the study’s primary endpoint for superiority. SCR is defined as Clinical Response of the treated episode of CDI and no recurrence of the infection through 30 days after the end of treatment.

Patients treated with ridinilazole, a precision antibiotic, experienced substantially less recurrence of C. diff. infection as compared to patients administered vancomycin (nominal p-value = 0.0002). Recurrence, for purposes of the Ri-CoDIFy study, is defined as a new episode of diarrhea ( greater than 3 unformed bowel movements) in a 1-day period with a positive C. difficile test that requires CDI antimicrobial treatment in subjects who achieved Clinical Response. Particularly promising results were identified in patients who were considered high-risk, including those considered immunocompromised or with a history of COVID-19 infection.

Full results from the Ri-CoDIFy study will be presented at upcoming medical conferences and published in a peer-reviewed medical journal. We will continue to evaluate the underlying data and perform additional analyses, including analyses specific to the microbiome, in order to discuss our complete package with the regulatory agencies. The use of ridinilazole is not approved and its safety and efficacy have not been evaluated by regulatory authorities, including the FDA.