Sanofi Pasteur Expands Phase II CDI Vaccine Study Into US

Sanofi Pasteur, the vaccines division of sanofi-aventis Group, has expanded its phase II clinical study of a vaccine against Clostridium difficile infection (CDI) into the US. The trial, started in the UK earlier this year, is investigating the safety and efficacy of Sanofi Pasteur’s CDI candidate vaccine in the US population.

The phase IIb trial is expected to recruit approximately 600 participants with acute CDI across the UK and in which the US participants will be randomised to four study groups, where three groups will receive vaccine, while the fourth group will be given a placebo vaccine. Reportedly, all subjects will receive standard of care antibiotics.

Sanofi Pasteur’s candidate vaccine uses a toxoid-based approach, which has been used extensively in licensed vaccines against tetanus, diphtheria and pertussis (whooping cough). The candidate vaccine has successfully completed phase I clinical trials in more than 200 participants to evaluate its safety and immunogenicity.

Michel DeWilde, senior vice president of research and development at Sanofi Pasteur, said: “While the target indication for the vaccine is prevention, this trial, in recently infected patients aims to provide early proof-of-concept of a vaccine approach to preventing recurring infection. Recurring infection occurs in at least 20% of patients experiencing a first CDI episode and even higher frequency in those who have had multiple episodes.”