2222. Impact of RBX2660 on the Intestinal Microbiota of Patients with Recurrent Clostridium difficile Infection Enrolled in the Randomized Placebo-Controlled PUNCH CD 2 Trial
Session: Poster Abstract Session: Microbiome: GI
Saturday, October 29, 2016
Room: Poster Hall
  • 2222-IDWeek 2016.pdf (1.1 MB)
  • Background: Perturbation of the intestinal microbiota, primarily by antibiotics, sets the stage for Clostridium difficile infection (CDI). Restoration of a variable intestinal microbiota protects against recurrence. The impact of RBX2660 on the gut microbiota of patients with recurrent CDI was evaluated in PUNCH CD 2, a multicenter, randomized, double-blinded, placebo-controlled, dose-ranging, phase 2b study.

    Methods: Patients with recurrent CDI were randomized to receive either: two doses of RBX2660 (Group A); two doses of placebo (Group B); or one dose of RBX2660 and one dose of placebo (Group C). RBX2660 is a microbiota-based drug manufactured from live human-derived microbes and targeted at the prevention of recurrent CDI. All therapies were administered via enema with doses 7 days apart. Success was defined as the absence of Clostridium difficile-associated diarrhea (CDAD) at 56 days.

    Longitudinal 16s rRNA analysis was performed on stool samples (n=120) from a total of 75 patients (Group A: n=23; Group B: n=22; Group C: n= 22) at baseline, 7 days and 30 days after the second dose of the blinded therapy sequence using the Illumina MiSeq platform. The variable region V4 was targeted to identify the operational taxonomic units (OTUs) in each sample.

    Results: OTU analysis demonstrated higher diversity between baseline and follow-up time points for all patients who responded successfully to their assigned treatment. This included Group B-two doses of placebo – in which 12 patients did not experience recurrent CDI symptoms prior to 56 days. Specifically, successful Group A patients had an increase in Akkermansia and Bacteroides from baseline; successful Group B and C patients had a decreased abundance of Enterobacter. Of the three groups of patients, those in Group A (two doses of active treatment) showed the greatest increase in bacterial diversity (number of OTUs) and abundance of taxa between baseline and all follow-up points.

    Conclusion: In this randomized controlled study of RBX2660 for recurrent CDI, 16s rRNA analysis found that patients who succeeded with their assigned therapy had a more diverse intestinal microbiota at 7 and 30 days compared with baseline.

    Courtney Jones, BS1, Bill Shannon, PhD, MBA2 and Sharina Carter, BS2, (1)Rebiotix Inc., Roseville, MN, (2)BioRankings LLC, St. Louis, MO


    C. Jones, Rebiotix Inc.: Employee , Salary

    B. Shannon, Rebiotix Inc.: Consultant , Consulting fee

    S. Carter, Rebiotix Inc.: Consultant , Salary from BioRankings LLC

    See more of: Microbiome: GI
    See more of: Poster Abstract Session

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.