Ken Blount, PhD: Effect of RBX2660 on Microbiome and Bile Acid Composition

New findings suggest the microbiota-based investigational live biotherapeutic, RBX2660, restored microbiome and bile acid compositions concurrent with clinical response in patients with recurrent C.difficile infection.

The findings additionally suggest the restorative changes may be characteristic of shifts from a post-antibiotic dysbiosis state to a healthier state.

In an interview with HCPLive at the Digestive Disease Week 2022 Annual Meeting, primary investigator Ken Blount, PhD, Chief Scientific Officer, Rebiotix and VP Microbiome Research, Ferring Pharmaceuticals, provided his perspective on the poster of distinction.

Blount noted that the investigational treatment at one week of treatment led to a restoration of both bacteroidia and clostridia in the 3 clinical trials, which continued until the end of the follow-up period, including up to 24 months.

"All of that told us that we were doing what we set out to do, which was to shift the microbiota in those trials from before to after treatment in a way that we felt could help resist or reduce recurrent C Diff infections," Blount said.

From the bile acid analysis in the study, investigators observed that prior to treatment, secondary bile acids were very low and primary bile acids were very high. After seven days of treatment in these trials, they found restoration towards predominance of the secondary bile acides produced by healthy microbiota.

"That sets up a very clear model in which prior to treatment patients are very vulnerable to see deferred growth and potentially recurrence whereas after treatment in these trials, they shifted to a state that you would call colonization resistance," Blount explained.

Blount continued to discuss safety signals of RBX2660, using the investigational agent for treatment of other diseases outside of C.diff, and the potential for other studies looking into the biotherapeutic.

The study, "Microbiome and Bile Acid Restoration Was Consistent Across Three Clinical Trials of RBX2660 for Recurrent Clostridiodes Difficile Infection: A Combined Analysis," was presented at DDW 2022.