Phase I Randomized, Placebo-Controlled, Double-Blind, Dose Ranging Study, Safety, Tolerability and Immunogenicity

A Phase I Randomized, Placebo-Controlled, Double-Blind, Dose Ranging Study of the Safety, Tolerability and Immunogenicity of Two Doses of a Clostridium Difficile Toxoid Vaccine, Alum Adsorbed, in Healthy Adult Volunteers (18 - 55 Years)

This Phase I, randomized, placebo-controlled, double-blinded, dose ranging study to assess the safety, tolerability, and immunogenicity of 2 dose levels of C. difficile vaccine. Population: healthy male and female adults, 18 to 55 years old.

This was a Phase I, randomized, placebo-controlled, double-blinded, dose ranging study designed to assess the safety, tolerability, and immunogenicity of C. difficile vaccine. The study was conducted in healthy male and female adults, 18 to 55 years old. Subjects was randomly assigned on Day 0 to receive one of two doses of C. difficile vaccine (50 or 100 mcg) or placebo (vehicle control containing alum).

Inclusion Criteria:

• Adult males or females, 18 - 55 years in good general health

Exclusion Criteria:

• Evidence of current C. difficile infection, as determined by a positive stool C. difficile cytotoxin assay at screening
• Evidence of any previous antibiotic-associated diarrhea caused by any etiology including C. difficile that required medical intervention or medication
• Active or inactive irritable bowel disease, chronic abdominal pain, chronic diarrhea of any etiology, or inflammatory bowel disease.