Summit’s Ridinilazole preserves gut microbiome of patients with C. difficile infection

The phase 2 trial evaluated ridinilazole against Standard of Care vancomycin across 100 patients. By preserving the gut microbiome, the Summit drug was demonstrated to have brought down the recurrence rates of CDI by 59% in comparison to vancomycin.

According to Summit, the gut microbiome is considered to play a key role in shielding the body against initial CDI and the start of recurrent disease. It is because of this reason that preserving the microbiome is thought to help to address the major unmet need in CDI.

Summit said that current CDI treatments cause microbiome damage which eventually could lead to recurrence of the bacterial disease.

Ridinilazole also showed clinical and statistical superiority over vancomycin in sustained clinical response, which captures if patients have been cured and are free from disease recurrence 30 days after completion of the treatment.

Overall ridinilazole was found to be significantly less disruptive to microbiota compared to vancomycin, which may help in reducing CDI recurrence as observed in the phase 2 study.

Summit R&D president David Roblin said: “These results show how the precision action of ridinilazole against C. difficile, and its corresponding lack of impact on the broader microbiome, led to greatly increased rates of sustained cures through decreased disease recurrence.

“Better prevention of recurrence is the next frontier in CDI therapy, with potential to reduce both patient morbidity and healthcare costs, which escalate further when initial treatment fails.”

CDI results from an infection of the colon by the bacterium C. difficile, which creates toxins that lead to inflammation and severe diarrhoea, and could be fatal in the most serious cases.

In preclinical efficacy studies, ridinilazole showed a targeted spectrum of activity that combined a potent bactericidal effect against all clinical isolates of C. difficile tested with minimal impact on other bacteria that are usually present in the gut microbiome.

In the US, ridinilazole has Qualified Infectious Disease Product (QIDP), Fast Track designation and Breakthrough Therapy designations from the US Food and Drug Administration.