Approval Probability
TA Base Rate
Adjusted LOA
ML Risk
Also known as C. difficile vaccine (previously studied formulation).
C. difficile vaccine · 4 trials · 3 indications
Injection site pain, redness, and swelling as self-reported in electronic diaries
Fever, vomiting, fatigue, headache, muscle pain, and joint pain as self-reported in electronic diaries
As elicited by investigator site staff
As elicited by investigator site staff
First episode of medically attended and clinically meaningful primary CDI incidence per 1000 person- years of follow- up
First episode of medically attended primary CDI incidence per 1000 person- years of follow- up
First episode of clinically meaningful primary CDI incidence per 1000 person- years of follow- up
Injection site pain, redness, and swelling as self-reported in electronic diaries
Vomiting, diarrhea, headache, fatigue, new or worsening muscle pain, new or worsening joint pain, and fever, as self-reported in electronic diaries
As elicited by investigational site staff
As elicited by investigational site staff
As elicited by investigational site staff
As measured at the central laboratory
Injection site pain, redness, and swelling as self-reported in electronic diaries
Vomiting, diarrhea, headache, fatigue, new or worsening muscle pain, new or worsening joint pain, and fever, as self-reported in electronic diaries
As elicited by investigational site staff
As elicited by investigational site staff
As elicited by investigational site staff
As measured at the central laboratory
As measured at the central laboratory
As measured at the central laboratory
As measured at the central laboratory
| Arm | Type | Description |
|---|---|---|
| C.difficile vaccine | EXPERIMENTAL | Novel vaccine formulation |
| Saline Placebo | OTHER | - |
| C. difficile vaccine formulation 1, Schedule 2 (Phase 1) | EXPERIMENTAL | Novel vaccine formulation 1 |
| C. difficile vaccine formulation 2, Schedule 3 (Phase 1) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 3, Schedule 2 (Phase 1) | EXPERIMENTAL | Novel vaccine formulation 3 |
| C. difficile vaccine formulation 1, Schedule 4 (Phase 1) | EXPERIMENTAL | Novel vaccine formulation 1 |
| C. difficile vaccine formulation 2, Schedule 4 (Phase 1) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 3, Schedule 4 (Phase 1) | EXPERIMENTAL | Novel vaccine formulation 3 |
| C. difficile vaccine (previously studied formulation) Schedule 1 (Phase 1) | ACTIVE_COMPARATOR | Previously studied C. difficile vaccine formulation |
| C difficile vaccine formulation 2, Schedule 1 (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 2, Schedule 4 (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 2, Schedule 5 (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 2, Schedule 6 (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine (previously studied formulation) , Schedule 1 (Phase 2) | ACTIVE_COMPARATOR | Previously studied C. difficile vaccine formulation |
| C. difficile vaccine formulation 2, Schedule 7 (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 2, Schedule 1, (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 2, Schedule 4, (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 2, Schedule 8, (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| C. difficile vaccine formulation 2, Schedule 9, (Phase 2) | EXPERIMENTAL | Novel vaccine formulation 2 |
| Saline placebo, Schedule 4 (Phase 2) | PLACEBO_COMPARATOR | Saline placebo |
| Arm Label: Month 0, 1 and 3 Schedule | EXPERIMENTAL | - |
| Day 1, 8, and 30 Schedule | EXPERIMENTAL | - |
| Low dose C diff vaccine | EXPERIMENTAL | - |
| Low dose C diff vaccine + adjuvant | EXPERIMENTAL | - |
| Mid dose C diff vaccine | EXPERIMENTAL | - |
| Mid dose C diff vaccine + adjuvant | EXPERIMENTAL | - |
| High dose C diff vaccine | EXPERIMENTAL | - |
| High dose C diff vaccine + adjuvant | EXPERIMENTAL | - |
| Name | Type | Description |
|---|---|---|
| C.difficile vaccine | BIOLOGICAL | C.difficile vaccine given as an intramuscular injection |
| Saline Placebo | OTHER | 0.9% sodium chloride solution given as a intramuscular injection |
| C. difficile vaccine (previously studied formulation). | BIOLOGICAL | Toxoid based Clostridioides difficile vaccine (previously studied formulation) given as an intramuscular injection |
| C. difficile vaccine formulation 1. | BIOLOGICAL | C. difficile vaccine formulation 1 given as an intramuscular injection |
| C. difficile vaccine formulation 2. | BIOLOGICAL | C. difficile vaccine formulation 2 given as an intramuscular injection |
| C. difficile vaccine formulation 3. | BIOLOGICAL | C. difficile vaccine formulation 3 given as an intramuscular injection |
| Saline Placebo. | OTHER | 0.9% sodium chloride solution given as an intramuscular injection |
| C. difficile vaccine with adjuvant | BIOLOGICAL | C. difficile vaccine with adjuvant administered at Month 0, 1, and 3. |
| Placebo | BIOLOGICAL | Placebo administered at Month 0, 1, and 3. |
| C. difficile vaccine | BIOLOGICAL | 0.5 mL IM injection |
| C. difficile vaccine +adjuvant | BIOLOGICAL | 0.5 mL IM injection |
Who Can Join the Study (Inclusion Criteria): • People with recent or future planned contact with healthcare systems, recent antibiotic exposure, or a diagnosis of certain chronic medical conditions. Who Cannot Join the Study (Exclusion Criteria): * Anyone who has had CDI before. * Anyone who has ...
The C. difficile vaccine is an investigational vaccine being developed by Pfizer to prevent Clostridioides difficile associated disease, including Clostridium difficile infection. It is designed to be given to older adults, a group at elevated risk for C. difficile disease. It is not approved and remains in clinical development.
The C. difficile vaccine is being studied to prevent Clostridium difficile associated disease and Clostridioides difficile associated disease in older adults. Clinical trials have enrolled healthy volunteers aged 50 and older, and the ongoing Phase 3 study enrolls people 65 years of age and older. No approved indication exists for this vaccine.
Pfizer, Inc. (ticker PFE) is the developer of the C. difficile vaccine. Pfizer is running the clinical program, including a large Phase 3 trial in adults 65 years and older and earlier Phase 1 studies of the vaccine with and without adjuvant.
The C. difficile vaccine is in clinical development, with Phase 1 and Phase 3 studies. The Phase 3 trial NCT07282665 is recruiting, while Phase 1 studies NCT05805826, NCT02052726, and NCT01706367 have been active or completed. The vaccine is investigational and has not been approved by the FDA.
The C. difficile vaccine program includes NCT07282665, a recruiting Phase 3 study in people 65 and older across the United States, Argentina, Japan, and the United Kingdom, and NCT05805826, an active Phase 1 study in healthy adults. Completed Phase 1 trials include NCT02052726 and NCT01706367.