Results from a Randomized Placebo-Controlled Clinical Trial of a RBX2660-a Microbiota-based Drug for the Prevention of Recurrent Clostridium difficile Infection. Journal Article


Authors: Dubberke, ER; Lee, CH; Orenstein, R; Khanna, S; Hecht, G; Gerding, DN
Article Title: Results from a Randomized Placebo-Controlled Clinical Trial of a RBX2660-a Microbiota-based Drug for the Prevention of Recurrent Clostridium difficile Infection.
Abstract: Background: Despite advancements, recurrent Clostridium difficile infections (CDI) remain an urgent public health threat with insufficient response rates to currently-approved antibiotic therapies. Microbiota-based treatments appear effective, but rigorous clinical trials are required to optimize dosing strategies and substantiate long-term safety. Methods: This randomized, double-blind, placebo-controlled Phase 2B trial (NCT02299570) enrolled adult patients with two or more CDI recurrences to receive: two doses of RBX2660, a standardized microbiota-based drug (Group A); two doses of placebo (Group B); or one dose of RBX2660 followed by one dose of placebo (Group C). Efficacy was defined as prevention of rCDI for 8 weeks following treatment. Participants who recurred within 8 weeks were eligible to receive up to two open-label RBX2660 doses. The primary endpoint was efficacy for Group A compared to Group B. Secondary endpoints included the efficacy of Group C compared to Group B, combined efficacy in the blinded and open-label phases, and safety for 24 months. Results: The efficacy for Groups A, B, and C were 61%, 45%, and 67%, respectively. The primary endpoint was not met (P=.152). One RBX2660 dose (Group C) was superior to placebo (Group B; P=.048), and the overall efficacy (including open-label response) for RBX2660-treated participants was 88.8%. Importantly, the proportion of adverse or serious adverse events did not differ significantly among treatment groups. Conclusions: One but not two doses of RBX2660 was superior to placebo in this randomized, placebo-controlled trial. These data provide important insights for a larger Phase 3 trial and continued clinical development of RBX2660.
Journal Title: Clinical Infectious Diseases
ISSN: 1058-4838
Publisher: Unknown  
Date Published: 2018