Clinical Trial: Safety, Tolerability, and Immunogenicity of a Clostridium Difficile Toxoid Vaccine in Healthy Elderly Volunteers

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Phase I Randomized, Placebo-Controlled, Double-Blind, Dose Ranging Study of the Safety, Tolerability and Immunogenicity of a Clostridium Difficile Toxoid Vaccine, Alum Adsorbed, in Healthy Elderly V

Brief Summary: The purpose of this study is to determine the safety and tolerability of a modified C. difficile vaccine at 3 dose levels compared with a placebo control administered via intramuscular injection in healthy elderly subjects aged > or = 65 years. This is the companion study to H-030-008, in which healthy younger adults have already been dosed.

Detailed Summary: Clostridium difficile is the leading infectious cause of nosocomial diarrhea in developed countries. Hospital outbreaks of Clostridium difficile-associated diarrhea (CDAD) are associated with substantial patient morbidity and mortality. Conventional therapy with antibiotics often results in secondary infection with resistant organisms or clinical relapse after discontinuation of the antimicrobial course. New strategies are needed to limit the impact of this opportunistic pathogen. Considerable evidence exists that immunity against C. difficile toxins may be effective in controlling CDAD. 48 subjects will be enrolled to receive one of three dose levels of modified C difficile vaccine or placebo administered on a 3-dose schedule. The study consists of a 30-day screening period, a 70-day treatment period, one follow-up phone interview 2 months after the last vaccination, and one follow-up clinic visit 6 months after the last vaccination.
Sponsor: Sanofi

Current Primary Outcome: Number of Participants Reporting Treatment-Emergent Adverse Events Post-vaccination With Either One of Three Formulations of the Clostridium Difficile Vaccine or a Placebo Vaccine. [ Time Frame: Day 0 to up to 70 days post first vaccination ]

Original Primary Outcome: Safety and Tolerability

Current Secondary Outcome: Number of Participants Achieving Seroconversion of Serum Immunoglobulin G (IgG) After Vaccination With Either a Formulation of C. Difficile Toxoid Vaccine or a Placebo Vaccine. [ Time Frame: Day up to Day 236 post first vaccination ]

Seroconversion was defined as a ≥ 4-fold increase from baseline in a subject's specific IgG levels: Serum Levels of Anti-toxin Immunoglobulin (IgG) against toxin A and toxin B in enzyme units (EU) were assessed by enzyme linked immunosorbent assay (ELISA).


Original Secondary Outcome: Immunogenicity

Information By: Sanofi

Dates:
Date Received: September 16, 2005
Date Started: November 2005
Date Completion:
Last Updated: April 9, 2012
Last Verified: April 2012