Microbiota-Based Live Biotherapeutic Demonstrates Efficacy in Patients With Recurrent C. Difficile Infection

Trials show a consistent efficacy profile and a consistent safety profile for RBX2660 in reducing the recurrence of C. difficile infection.

RBX2660, an investigational microbiota-based live biotherapeutic, has been shown to consistently reduce the recurrence of C. difficile infection (CDI), according to the results of 5 prospective trials evaluating 723 actively treated participants. The investigators said that up to 78.9% of study participants treated with RBX2660 remained recurrence-free for 8 weeks post treatment.

“For years, people with recurrent C. difficile infection haven’t had an available, standardized treatment option to break the cycle of recurrence or clinically address the health of their gut microbiome composition that puts them at risk for this highly communicable disease, and they still do not,” said Teena Chopra, MD, MPH, professor of medicine in the Division of Infectious Disease at Wayne State University School of Medicine, in a press release. “The important data from the Ferring microbiome-based biotherapeutic trials provide a significant milestone for the C. difficile community to hopefully one day have an improved treatment option for patients suffering from this disease.”

Study participants who did not respond to the initial treatment were given an optional additional treatment course, resulting in an overall treatment success rate of up to 84.4%, according to the investigators. The majority of individuals who responded to the first course of treatment were CDI-free for 6 months and up to 2 years, with a sustained clinical response success rate of up to 92.1%.

C. difficile infection often is marked by a vicious cycle of recurrence, wherein patients’ infection may return within days after antibiotic treatment. This can significantly impact a person’s health and well-being, and burden the healthcare system,” said Ken Blount, PhD, chief scientific officer at Rebiotix, in the release. “The shift of the microbiome observed in our study provides the first evidence linking phase 3 efficacy data of RBX2660 with improved microbiota composition of the gut. This finding is important, as this is during a time when a person recovering from CDI is most vulnerable for reinfection, and these changes were durable for at least 6 months.”

According to the investigators, the percentage of patients who reported treatment-emergent adverse events (TEAEs) in the RBX2660 group was similar to that seen in the cohort receiving standard-of-care plus placebo. The majority of TEAEs were mild to moderate in severity, and there were no potentially life-threatening TEAEs observed.

“These data provide the totality of evidence culminating in over a decade’s worth of work that demonstrates a consistent efficacy profile for RBX2660, and importantly, a consistent safety profile across 5 prospective trials,” said Lindy L. Bancke, PharmD, head of clinical development at Rebiotix, in the release. “They reinforce the enormous potential of microbiome-based therapeutics to transform the care of people suffering from rCDI.”

The analysis included 3 phase 2 trials and 2 phase 3 trials, in which all participants were 18 years of age or older and had at least 1 recurrence after a primary episode of CDI. Further, all participants had completed at least 1 round of standard-of-care oral antibiotic therapy.

REFERENCE

Ferring presents complete data across five RBX2660 trials demonstrating consistent and durable efficacy in recurrent C. difficile infection, as well as multiple analyses demonstrating positive shifts in microbiome properties [news release]. BusinessWire; September 29, 2021. Accessed September 30, 2021. https://www.businesswire.com/news/home/20210929005597/en