Non-Toxigenic C. difficile Reduces Recurrence of Infection in Phase II Trial
Recurrence rate 2% in colonized patients (Apr. 22)
Results have been reported from a phase II study of VP20621 (non-toxigenic Clostridium difficile; ViroPharma Inc.), a new treatment approach for preventing recurrent C. difficile infection (CDI). CDI is a common gastrointestinal (GI) infection that typically occurs in older adults after the use of antibiotics. VP20621 contains the spores of a naturally occurring non–toxin-producing strain of C. difficile.
The new randomized, double-blind study was designed to determine the tolerability of liquid VP20621 dosed orally for up to 14 days in 168 adults previously treated for CDI with oral vancomycin or metronidazole. After completing the antibiotic treatment, the subjects were randomly assigned to receive VP20621 doses of 104 spores once daily (QD) for 7 days (n = 41); 107 spores QD for 7 days (n = 43); 107 spores QD for 14 days (n = 41); or placebo (n = 43). The subjects’ median age was 59 years; 39% were 65 years old or older; and 62% were female.
Viable non-toxigenic C. difficile was detected in stool culture (the study’s primary endpoint) in 54%, 79%, and 73% of subjects treated with the low, medium, and high doses of VP20621, respectively, compared with 0% of the placebo group. In addition, across all dose groups, VP20621 reduced the incidence of CDI recurrence (a secondary endpoint) by 50% or more versus placebo (5%–15% vs. 30%, respectively). Antibacterial treatment was also reduced by 50% or more in the VP20621 groups compared with the placebo group (9%–15% vs. 33%, respectively). The CDI recurrence rate was 2% (2/86) in the subgroup of patients successfully colonized with VP20621.
The only notable adverse event was mild-to-moderate headache, which was reported by 10% of the subjects treated with VP20621 and by 2% of the placebo group.
Antibiotics, including those used to treat acute CDI, disrupt the normal GI flora, which makes individuals susceptible to C. difficile colonization. According to the drug’s developer, VP20621 uses non-toxigenic spore-based technology as a potential means of recolonizing and protecting the GI tract. The goal of VP20621 dosing after antibiotic exposure is to colonize the GI tract with this non-toxigenic strain of C. difficile, thereby preventing colonization by toxigenic strains.
Hospital-acquired infections (HAIs) remain a serious challenge to the U.S. health care system, and CDI is one of the most common HAIs. The incidence of CDI in U.S. health care facilities has more than doubled approximately every 5 years since 1999. Moreover, the reported mortality rates from CDI in the U.S. have more than quadrupled in the last decade to 14,000 per year. Elderly patients exposed to antibiotics, long-term care patients, and those with a serious underlying illness are at increased risk for developing the infection.
Typical symptoms of CDI include potentially severe diarrhea, fever, nausea, abdominal pain, and dehydration, which can lead to life-threatening complications, such as shock, megacolon, peritonitis, and perforation of the colon.
Source: ViroPharma Inc.; April 22, 2013.