Lack of Association with Patient Demographics and Outcomes in PUNCH CD 2, a Randomized Controlled Trial of RBX2660, a Microbiota-based Drug for Recurrent Clostridium difficile Infection

Gail Hecht, MD, Robert Orenstein, DO, Erik R.Dubberke, MD, MSPH, Christine Lee, MD, Sahil Khanna, MBBS, MS

Background

• Microbiota therapy is gaining acceptance for preventing recurrent Clostridium difficile infection (CDI).
• RBX2660 is a microbiota-based drug derived from healthy human donors using a standardized, quality-controlled manufacturing process.
• One dose of RBX2660 was demonstrated to be safe and effective for preventing rCDI in a randomized, double-blind, placebo controlled study (PUNCH CD 2; reported by Dubberke et al., ID Week, Oct 2016).
• Recent microbiota-based trials suggested suggested that outcomes may correlate with patient demographics.
• Key demographics of subjects treated in the PUNCH CD 2 trial were evaluated for impact on treatment.

Methods

• A total of 133 patients with recurrent CDI were enrolled in the PUNCH CD 2 clinical trial at 21 sites in the USA and Canada (Trial #: NCT02299570).
• Patients were randomized to receive: 2 doses of RBX2660 (Group A); 2 doses of placebo (Group B); or 1 dose of RBX2660 followed by 1 dose of placebo (Group C).
• Therapies were administered via enema 7 days apart.
• The first blinded treatment dose was administered 24-48 hours after completion of antibiotic treatment.
• Success was defined as the absence of C. difficile-associated diarrhea at 8 weeks following completion of the last blinded treatment.
• Demographic information was collected at the time of enrollment, with success and failure designations applied after the study blind was lifted.
• Logistic regression was used to determine whether outcomes correlated with specific demographic characteristics.

RBX2660

• One dose of RBX2660 contains 50 g of human stool per 150 mL of suspension in a single-dose ready-to-use enema bag.
• Stored frozen at ≤−80°C at the manufacturer and shipped frozen to the site as needed in a temperature-controlled container.
• Manufactured using standardized, quality-controlled processes with guaranteed minimum quantity of microbes.

Results

• Logistic regression analysis was conducted with data from 127 patients treated in the blinded phase of the PUNCH CD 2 trial.
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Conclusions

• The efficacy outcome of RBX2660 did not depend on sex, age, region of the clinical trial center, or the antibiotic regimen completed prior to RBX2660 treatment.
• The broad benefit of RBX2660 among patient demographics underscores its merit for further clinical evaluation for preventing rCDI.