Benzinga | Jul 12, 2021 08:30AM EDT

Summit Therapeutics Highlights Presentation Of Data From Phase II Studies At 31st European Congress of Clinical Microbiology & Infectious Diseases

Summit Therapeutics Inc. (NASDAQ:SMMT) ("Summit" or the "Company") is today displaying three preeminent ePosters at the prestigious 31st European Congress of Clinical Microbiology & Infectious Diseases (ECCMID). Two ePosters bring increased awareness and understanding of the significance of data generated using shotgun metagenomic analyses to compare ridinilazole and vancomycin treated patients with Clostridioides difficile infection (CDI) from our Phase II CoDIFy clinical trial. Vancomycin, discovered in the 1950's, is the current standard of care for the treatment of C. difficile infection. Highlights of the ePosters include data demonstrating the relative impact on the gut microbiota as well as the gut resistome of ridinilazole and vancomycin. Ridinilazole's recently discovered novel mechanism of action is also described.

Ridinilazole is Summit Therapeutics' investigational first-in-class drug currently in two pivotal Phase III Ri-CoDIFy clinical trials. The objective of these trials is to obtain approval for ridinilazole as a first-line therapy for the treatment of initial C. difficile infection, and to show superiority in sustained clinical response (cure at initial response and no recurrence within 30 days after end of treatment). Ridinilazole is currently under investigation for use by several regulatory authorities including the FDA and the EMA.

Summit's poster presentations provide demonstrable scientific evidence of the following:

* Ridinilazole showed no increase in the gut resistome. Ridinilazole demonstrated no impact on the gut resistome as compared to vancomycin, which displayed an expansion of the presence of Enterobacteriaceae (potentially bad bacteria) in the gut and corresponding increase in antibiotic resistance genes in the gut resistome in a Phase II study.

* Ridinilazole showed evidence of preservation and minimal impact to the gut microbiome. In a Phase II study, treatment with ridinilazole compared to vancomycin demonstrated a significant sparing effect on the gut microbiome, supporting the production of protective secondary bile acids. Secondary bile acids are a key component in preventing recurrence of C. difficile infection. It was found that vancomycin treatment was associated with significant changes to the gut microbiome, impacting the microbiome's ability to produce protective secondary bile acids, increasing the risk of C. difficile infection recurrence.

* Ridinilazole has the potential to be the first novel mechanism of action antibiotic approved in over ten years. Ridinilazole's novel mechanism of action involves binding to the minor groove of Clostridioides difficile bacteria's DNA. This is believed to be the primary mechanism through which ridinilazole elicits its bactericidal action against C. difficile bacteria.

"The gut microbiome is a critical ecosystem that plays an important role in the overall health of the human body," stated Dr. Maky Zanganeh, the Chief Operating Officer of Summit. "The results of our shotgun metagenomic analyses evidencing how ridinilazole preserved the gut microbiome, including its ability to produce secondary bile acids, provides further scientific support for our confidence in ridinilazole's value for the treatment of C. difficile infection and, particularly, in ridinilazole's ability to reduce relative CDI recurrence. These results provide a strong mechanistic rationale as to why a lower rate of recurrence of C. difficile infection was observed in our Phase II study for patients taking ridinilazole as compared to vancomycin. The combination of these studies and discoveries provide us with further data in support of the intended efficacy of ridinilazole."

"There is the promise in ridinilazole for a new antibiotic drug to significantly impact the C. difficile infection treatment market in a material and positive manner. The need exists now. In our opinion, upon FDA and worldwide regulatory approval, a new era for friendly patient and physician infectious disease management is upon us. This journey has not been easy. It is not yet over. But it is a worthwhile journey, and Team Summit is pleased to be playing a leadership role," said Bob Duggan, Summit's Chairman and Chief Executive Officer. "C. difficile infection is an especially insidious disease that remains an unmet medical need, as emphasized by the US Centers for Disease Control and Prevention (CDC) listing it as one of five pathogens that is currently an urgent threat to public health. The results of these metagenomic analyses add to the increasing body of data supporting ridinilazole. Summit Therapeutics intends for ridinilazole to provide high therapeutic efficacy while minimizing antibacterial resistance and disease recurrence. We believe ridinilazole continues to be well-positioned to achieve these stated goals."

Our three ePosters can be viewed as follows:

* ECCMID-designated Top Rated ePoster: Metagenomic Analysis of the Impact of the Precision Antibiotic Ridinilazole, Compared to Vancomycin, on the Gut Resistome in a Phase II Study Interactive Session S149 - 3e. Resistance detection / prediction approaches Monday, July 12, 2021 (16:00 to 17:00 CEST; 10:00am to 11:00am EDT)

* Metagenomic Analysis of the Differential Impact of Ridinilazole and Vancomycin on the Gut Microbiota in a Phase II Study Review Session S15: Methods for improving diagnostics and strain typing-Category: 4. Diagnostics Monday, July 12, 2021 (14:15 to 15:15 CEST; 8:15am to 9:15am EDT)

* Identification of the Mechanism of Action for Ridinilazole, a Phase III Antibiotic for Treatment of Clostridioides difficile Session S163-5a. Mechanism of action new compounds, preclinical data, & pharmacology of antibacterial agents Available throughout the ECCMID Conference

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