Trial Search Results

Study of a Candidate Clostridium Difficile Toxoid Vaccine in Subjects at Risk for C. Difficile Infection

The aim of this study is to evaluate the efficacy of the candidate Clostridium difficile vaccine to prevent primary symptomatic C. difficile infection (CDI) in subjects a risk for CDI where there is a substantial unmet medical need.

Primary objective:

- To assess the efficacy of the C. difficile vaccine in preventing the onset of symptomatic primary CDI confirmed by polymerase chain reaction (PCR) in adult subjects aged ≥ 50 years who are at risk for CDI and have received at least 1 injection.

Secondary Objectives:


- To assess prevention of symptomatic PCR-confirmed primary CDI cases after 3 injections administered at 0, 7, and 30 days

- To assess prevention of symptomatic PCR-confirmed primary CDI cases after completion of at least 2 injections.


- To describe the immunogenicity to toxin A and toxin B in the subset of subjects at specific time points.


- To describe the safety profile of all subjects who receive at least 1 injection.

Stanford is currently accepting patients for this trial.

Lead Sponsor:

Sanofi Pasteur, a Sanofi Company

Stanford Investigator(s):


  • Biological: C. difficile Toxoid Vaccine
  • Biological: Placebo: 0.9% normal saline


Phase 3


Inclusion Criteria:

   - Aged ≥ 50 years on the day of inclusion

   - Informed consent form has been signed and dated

   - Able to attend all scheduled visits and to comply with all trial procedures

   - Covered by health insurance (if required)

   - Must fulfill at least 1 of the following criteria

Risk Stratum 1:

   - Has had at least 2 hospital stays, each lasting at least ≥ 24 hours, in the 12 months
   before enrollment, and

   - Has received systemic (not topical) antibiotics in the 12 months before enrollment, or

Risk Stratum 2:

   - Is anticipated to have an in-patient hospitalization for a planned surgical procedure
   within 60 days of enrollment. The impending hospital stay is planned to be ≥ 72 hours
   for a surgery involving 1 of the following:

   - Kidney/bladder/urinary system

   - Musculoskeletal system

   - Respiratory system

   - Circulatory system

   - Central nervous system.

Exclusion Criteria:

   - Subject is pregnant, or lactating, or of childbearing potential (to be considered of
   non-childbearing potential, a female must be post-menopausal for at least 1 year,
   surgically sterile, or using an effective method of contraception or abstinence from
   at least 4 weeks prior to the first vaccination and until at least 4 weeks after the
   last vaccination)

   - Participation in the 4 weeks preceding the first trial vaccination or participation
   during the present trial period in another clinical trial investigating a vaccine,
   drug, medical device, or medical procedure

   - Receipt of any vaccine in the 4 weeks preceding the first trial vaccination except for
   influenza (seasonal or pandemic) and pneumococcal vaccines. This exception includes
   monovalent pandemic influenza vaccines and multivalent influenza vaccines

   - Previous vaccination against C. difficile with either the trial vaccine, another
   vaccine, or monoclonal antibodies

   - Diarrhea on day of enrollment

   - Self-reported current or prior CDI episode

   - Anticipated or current receipt of kidney dialysis treatment

   - History of gastrointestinal surgery for gastrointestinal malignancy (Note:
   Colonoscopy, polypectomy, and appendectomy are not exclusion criteria.)

   - History of inflammatory bowel disease, irritable bowel syndrome (must include diarrhea
   as a symptom), colostomy, or small or large intestine bowel surgery where resection
   was performed

   - Receiving enteral feeding (e.g., nasogastric, gastrostomy, and jejunostomy tube

   - Known or suspected congenital or acquired immunodeficiency; or receipt of
   immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy,
   within the preceding 6 months; or long-term systemic corticosteroid therapy
   (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)

   - Known systemic hypersensitivity to any of the vaccine components, or history of a
   life-threatening reaction to the vaccine used in the trial or to a vaccine containing
   any of the same substances

   - Self-reported thrombocytopenia, contraindicating intramuscular vaccination

   - Deprived of freedom by an administrative or court order, or in an emergency setting,
   or hospitalized involuntarily

   - Current alcohol abuse or drug addiction that might interfere with the ability to
   comply with trial procedures in the opinion of the Investigator

   - Chronic illness that, in the opinion of the investigator, is at a stage where it might
   interfere with trial conduct or completion

   - Moderate or severe acute illness/infection (according to investigator judgment) on the
   day of vaccination or febrile illness (temperature ≥ 38.0°C [≥ 100.4°F]). A
   prospective subject should not be included in the study until the condition has
   resolved or the febrile event has subsided

   - Identified as an Investigator or employee of the Investigator or study center with
   direct involvement in the proposed study, or identified as an immediate family member
   (i.e., parent, spouse, natural or adopted child) of the Investigator or employee with
   direct involvement in the proposed study.

Ages Eligible for Study

50 Years - N/A

Genders Eligible for Study


Now accepting new patients

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305
Alison Pepper