About Clostridium difficile Infection

With about 29,000 patient deaths a year, the U.S. Centers for Disease Control has termed Clostridium difficile (C. diff.) infection an urgent public health threat. Although estimates vary, there are between 500,000 and 700,00 cases of C. diff. infection in the U.S.

Risk Factors

  • Antibiotic use
  • Older age (> 65 years)
  • Exposure to health care facilities
  • Severe underlying disease
  • Compromised immune response

The Problem of Recurrence

Antibiotic therapy is the standard treatment following an initial diagnosis C. diff. However, approximately 25%1 of patients initially cured will experience a recurrence. Each recurrence predisposes to further recurrence. After two or more episodes of recurrence, the risk of subsequent recurrence may reach 65%.1

Breaking the Cycle of Recurrence

In healthy individuals, the microbial balance in the gut microbiota prevents the development of symptomatic C. diff. infection. However, antibiotics disturb this balance, allowing C. diff. infection to colonize the large intestine of people at risk of infection.2

The Promise of Microbiota Restoration Therapy (MRT)

Rebiotix Microbiota Restoration Therapy (MRT) presents the possibility to change the therapeutic landscape for recurrent C. diff. infection.

A Phase 2 randomized placebo-controlled double-blind study of lead MRT product, RBX2660, for recurrent C. diff. has completed enrollment. An oral formulation for C. diff. prevention and additional MRT drugs are under development.

Key Milestones

Rebiotix is making excellent progress in hitting prerequisite milestones for commercialization of RBX2660 for recurrent C. diff.:

  • PUNCH CD study – Open label study completed in October 2014 demonstrated an overall success of 87.1% with a good safety profile.
  • PUNCH CD 2 – Randomized, double-blind, placebo controlled study. Read out of study results expected Q4 2015.

Special FDA Designations for RBX2660:

  • Fast Track – May 2013
  • Orphan Drug – March 2014
  • Breakthrough Therapy – October 2015


  1. Kelly CP. Can we identify patients at high risk of recurrent Clostridium difficile infection? Clin Microbiol Infect. 2012; 18 (Suppl. 6): 21–27.
  2. Theriot CM, Young VB. Interactions Between the Gastrointestinal Microbiome and Clostridium difficile. Annu Rev Microbiol. 2015;69:445-61.