Interim Analysis of a Phase 3 Open-Label Study Indicates Safety and Efficacy of RBX2660, an Investigational Live Biotherapeutic, in a “Real-world” Population of Patients with Recurrent Clostridioides difficile Infection

Colleen Kraft MD¹, Sahil Khanna MBBS², Maha Assi MS MPH³, Paul Feuerstadt MD⁴, Adam Harvey PhD⁵, Lindy Bancke PharmD^5
1Emory University, Atlanta, GA, USA; ²Mayo Clinic, Rochester, MN, USA; ³Infectious Disease Consultants, Wichita, KS, USA; ⁴Gastroenterology Center of Connecticut, Hamden, CT, USA; ⁵Rebiotix Inc, Roseville, MN, USA

Background

• Microbiota-restoring approaches are being widely evaluated for treatment of recurrent Clostridioides difficile infections (rCDI) in controlled clinical studies.
• Eligibility criteria in clinical trials of investigational treatments are often narrowly defined, with rigid diagnostic criteria and exclusion of patients with potentially confounding co-morbid conditions, such as Inflammatory Bowel Disease (IBD) and Irritable Bowel Syndrome (IBS).
• RBX2660, an investigational microbiota-based formulation, has shown efficacy in preventing rCDI through 8 weeks in several previous clinical trials, including two randomized, placebo-controlled studies (NCT02299570; NCT03244644).
• Herein we report an interim analysis of PUNCH CD3-OLS, a Phase 3 open-label study evaluating the safety and efficacy of RBX2660 in the reduction of rCDI recurrence (NCT03931941).
• PUNCH-CD3-OLS eligibility criteria is less restrictive to allow evaluation in a population more typical of real-world rCDI clinical practice.

Conclusions

• RBX2660 demonstrated safety and efficacy under real world conditions for reduction of rCDI in adult participants following antibiotic therapy with a consistent and favorable safety profile for single or multiple doses of RBX2660.
• These interim results replicate the safety and efficacy profile demonstrated in previous studies of RBX2660, contributing to the preponderance of evidence compiled over the formulation’s development program.
• Furthermore, the observed RBX2660 safety and efficacy profile in a population inclusive of participants with IBD and IBS demonstrates that previously established results for RBX2660 remain robust in a broader population more typical of real-world rCDI clinical practice.
• This study is ongoing and continues to enroll subjects.