Study of a Clostridium Difficile Toxoid Vaccine (ACAM-CDIFF™) in Subjects With Clostridium Difficile Infection

A Phase II Randomized, Placebo-Controlled, Double-Blind, Dose Ranging Study of A Clostridium Difficile Toxoid Vaccine (ACAM-CDIFF™) in Subjects With Clostridium Difficile Infection (CDI)

Primary objective: To compare the event rate of CDI in groups assigned to ACAM-CDIFF™ vaccine versus placebo in the 9 week period after the third dose of the study vaccine in subjects with first episode of CDI receiving antibiotics standard of care.

Secondary objective: To evaluate the safety of all dose groups of ACAM-CDIFF™ vaccine versus placebo in subjects with first episode of CDI receiving antibiotics standard of care.

This study is designed primarily to obtain information on the preliminary efficacy, safety and immunogenicity of ACAM-CDIFF™ vaccine, as compared to placebo in subjects who are experiencing their first event of CDI and are being treated with the antibiotic standard of care. This study will be conducted in the United States and United Kingdom. Adult subjects with limited chronic disease, who are currently receiving treatment for their first episode of CDI will be enrolled in this trial. Subjects will be required to be able to take oral antibiotics.

Inclusion Criteria:

1. Adult subjects, 18 - 85 years old, who understand the risks and benefits of participation and have provided written informed consent for the study.
2. Subjects who are experiencing a first event of CDI diagnosed within the last 10 days.
3. Subjects who are medically stable.
4. Subjects who are willing and able to comply with the study procedures and visit schedules outlined.

Exclusion Criteria:

1. Subjects who are currently on treatment for a recurrence of CDI.
2. Subjects who are currently or have recently been treated with immunoglobulin therapy.
3. Pregnant or breast feeding females.
4. Concurrent, acutely life-threatening diseases.