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NCT03918629 · ClinicalTrials.gov registry record · Phase 3
Clostridium Difficile Vaccine 2-Dose Versus 3-Dose Study
A Phase 3 study, sponsored by Pfizer.
- Completed
- Registry status
- Phase 3
- Development phase
- 1,994
- Enrollment target
NCT03918629: Completed Phase 3 study, sponsored by Pfizer.
NCT03918629 is a Phase 3 study that has completed, run by Pfizer. The registered enrollment target is 1,994 participants, above the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (158% higher). According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT03918629, a Phase 3 study, has completed, sponsored by Pfizer.
- COMPLETED
- Registry status
- Phase 3
- Development phase
- 1,994 participants
- Enrollment target
Study Summary
This study will investigate a Clostridium difficile vaccine in adults 50 years of age and older. In half the adults, all 3 doses given are the Clostridium difficile vaccine, and in half the adults, 2 of the 3 doses are the Clostridium difficile vaccine with the other dose containing no active ingredients. The study will look at the subjects' immune response to the vaccine and assess the safety and tolerability of a 2-dose regimen of Clostridium difficile vaccine compared to a 3-dose regimen of Clostridium difficile vaccine.
Primary Outcome
Adjusted GMCs and 2-sided 95% confidence intervals (CIs) of toxin A and toxin B specific neutralizing antibody levels were calculated by exponentiating the least square (LS) means and the corresponding CIs based on analysis of logarithmically transformed concentrations using a linear regression model with terms of baseline concentration (log scale) and vaccine group. EIP at Month 7 (EI7): all enrolled participants who received all 3 doses of investigational product; had blood drawn for assay tes
Interventions
- BIOLOGICAL Placebo
- BIOLOGICAL Clostridium difficile
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 1,994 participants |
| Start Date | 2019-04-01 |
| Est. Completion | 2020-12-22 |
| Phase | Phase 3 |
What the finished NCT03918629 record still lists
NCT03918629 is an interventional study that assigns participants to a tested intervention. Its 1,994 participants enrollment target places it among the larger protocols in the corpus, above the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (158% higher).
The record links to 0 conditions, and to 2 interventions - of which Placebo is the first listed.
NCT03918629 does not publish any study locations in the registry export this page uses.
Frequently Asked Questions
What is clinical trial NCT03918629 about?
NCT03918629 is a clinical study titled "Clostridium Difficile Vaccine 2-Dose Versus 3-Dose Study". This study will investigate a Clostridium difficile vaccine in adults 50 years of age and older. In half the adults, all 3 doses given are the Clostridium difficile vaccine, and in half the adults, 2 of the 3 doses are the Clostridium difficile vaccine with the other dose containing no active ingred...
What is the current status of trial NCT03918629?
This trial is currently completed. It is a Phase 3 study. The enrollment target is 1,994 participants. The study started on 2019-04-01. Estimated completion is 2020-12-22.
What interventions are being tested in trial NCT03918629?
The interventions under investigation include: Placebo (BIOLOGICAL), Clostridium difficile (BIOLOGICAL).
Who is sponsoring clinical trial NCT03918629?
This trial is sponsored by Pfizer, which has 1,845 total clinical trials registered on ClinicalTrials.gov.
Learn More About Clinical Trials
How this trial's enrollment target compares
Where NCT03918629's enrollment target sits among peer trials
1,994 106th of 2000 higher than 1,895 of 2,000 other Phase 3 trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other Phase 3 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
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