Rebyota Trial Subgroup Analysis: Results for People with Renal Comorbidities | IDWeek 2023

Second of two parts

A subgroup analysis of patients with Clostridioides difficile (C. difficile) infection and renal comorbidities showed that two-thirds responded to Rebyota (fecal microbiota, live), the first FDA-approved fecal microbiota for the prevention of recurrence Clostridioides difficile infection, according to findings presented today at the IDWeek 2023 meeting in Boston.

“These patients are at risk of a bad outcome,” said one of the investigators, Glenn Tillotson, Ph.D., M.Sc., a Virginia-based consultant to the pharmaceutical industry who has worked for Ferring Pharmaceuticals, the maker of Rebyota. “Two-thirds of patients saw a clinical outcome without any long-term adverse events.”

The FDA approved Rebyota in November 2022. The treatment is administered rectally and is made from donated stool. Rebyota is used after an individual has completed antibiotic treatment for recurrent C. difficile infection.

The findings presented in a poster at the IDWeek 2023 today compared a subgroup of 98 people with renal comorbidities in the PUNCH CD3-OLS trial of Rebyota with 304 study participants without renal comorbidities. The group with renal comorbidities was older (mean age 63.7 vs. 58.4), more likely to have had five or more episodes of C. difficile infection (21.4% vs. 10.9%) and more likely to be experiencing a high number of comorbidities (50% with a Charlson Comorbidity Index of 5 ore more vs. 18.4%).

Tillotson and his co-investigators found that a smaller proportion of the study participants with renal comorbidities experienced “treatment success” — defined as an absence of C. diff-related diarrhea through eight weeks after Rebyota was administered — than those without renal comorbidities (66.3% vs. 77.3%); Tillotson said the difference was not statistically significant. Renal disease is associated with an altered microbiome in the bowel that is favorable to C. difficile, according to Tillotson, and the ‘”disturbed microbiome” of patients with renal disease may explain what may be the slightly lower efficacy of Rebyota in patients with renal comorbidities.

The results also showed that a greater proportion of study participants with renal comorbidities had severe treatment-emergent adverse events than those without renal comorbidities (20 of 98, or 20.4% vs. 33 of 304, or 10.9%). Tillotson noted, however, that none of those adverse events were related to administration of Rebyota, and the majority were related to pre-existing conditions.

He said the results were the “the sort of information that guideline writers were looking” and may affect future recommendations of the Infectious Diseases Society of America and other groups.

Two of Tillotson’s co-authors on the poster are employees are employees of Ferring and others had ties to the company.