C. difficile Vaccine for C. difficile Infection
Recruiting in Palo Alto (17 mi)
+26 other locations
Age: 65+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Phase 1 & 2
Waitlist Available
Sponsor: Pfizer
No Placebo Group
Trial Summary
What is the purpose of this trial?An antibody is a substance your body makes to fight off infection. This study will explore the safety and antibody response of a vaccine to prevent severe diarrhea caused by a germ called Clostridoides difficile (C. diff). Three new formulations of the C. diff vaccine will be used in this study, in addition to a C. diff vaccine formulation that has been studied in previous clinical trials.
The purpose of this study is to understand if giving the new C. diff vaccine formulations helps people make as many antibodies as giving the previously studied C. diff vaccine formulation.
The study is divided into 2 phases.
Phase 1 will evaluate 3 new formulations of the C. diff vaccine and 2 dosing schedules spread out over 2 months or 6 months.
The Phase 1 portion of the study is seeking participants:
* who are healthy adults of 65 to 84 years of age
* who have not had a C. diff infection before
* who have not received a C. diff vaccine or C. diff monoclonal antibody therapy before.
All participants in Phase 1 will receive study injections with active vaccine or placebo at each vaccination visit, depending on the vaccine group to which they are assigned. A placebo does not contain any active ingredients. Participants in Phase 1 will attend at least 9 study visits and will take part in the study for approximately 18 months. Based on the results of Phase 1, 1 or 2 of the new C. diff vaccine formulations will be chosen for further study in Phase 2.
Phase 2 will evaluate the safety and effects of the new C. diff vaccine formulation(s) chosen in Phase 1.
The Phase 2 portion of the study is seeking participants:
* who are healthy adults ≥65 years of age
* who have not had a C. diff infection before
* who have not received a C. diff vaccine or C. diff monoclonal antibody therapy before.
Phase 2 participants will receive active C. diff vaccine or placebo at each vaccination visit. Participants in Phase 2 will attend at least 6 and up to 12 study visits and will take part in the study for up to 4 years.
Eligibility Criteria
Healthy adults aged 65-84 for Phase 1, and 50-84 for Phase 2, who've never had a C. diff infection or received any C. diff vaccine or therapy. Participants must be able to follow the study plan and give informed consent. Exclusions include those on immunosuppressive therapy, involved in other investigational studies, with certain medical conditions or history of severe allergies to vaccines.Inclusion Criteria
I can sign the consent form and follow the study's rules.
I am willing and able to follow all study requirements.
You are considered medically healthy based on your history, examination, and the investigator's discretion.
+1 more
Exclusion Criteria
I have never received an experimental vaccine or antibody therapy for C. difficile.
I do not have a serious chronic disorder that would prevent me from joining the study.
I am not on immunosuppressive therapy or have taken corticosteroids in the last 28 days.
+10 more
Participant Groups
The trial is testing three new formulations of a C. difficile vaccine against one previously studied formulation and a saline placebo to see if they're safe and can help the body produce antibodies against C. diff infection. The study has two phases: Phase 1 tests different dosing schedules; based on these results, one or two formulations will advance to Phase 2.
15Treatment groups
Experimental Treatment
Active Control
Group I: C. difficile vaccine formulation 3, Schedule 4 (Phase 1)Experimental Treatment2 Interventions
Novel vaccine formulation 3
Group II: C. difficile vaccine formulation 3, Schedule 2 (Phase 1)Experimental Treatment2 Interventions
Novel vaccine formulation 3
Group III: C. difficile vaccine formulation 2, Schedule 7 (Phase 2)Experimental Treatment2 Interventions
Novel vaccine formulation 2
Group IV: C. difficile vaccine formulation 2, Schedule 6 (Phase 2)Experimental Treatment1 Intervention
Novel vaccine formulation 2
Group V: C. difficile vaccine formulation 2, Schedule 5 (Phase 2)Experimental Treatment2 Interventions
Novel vaccine formulation 2
Group VI: C. difficile vaccine formulation 2, Schedule 4, (Phase 2)Experimental Treatment2 Interventions
Novel vaccine formulation 2
Group VII: C. difficile vaccine formulation 2, Schedule 4 (Phase 2)Experimental Treatment2 Interventions
Novel vaccine formulation 2
Group VIII: C. difficile vaccine formulation 2, Schedule 4 (Phase 1)Experimental Treatment2 Interventions
Novel vaccine formulation 2
Group IX: C. difficile vaccine formulation 2, Schedule 3 (Phase 1)Experimental Treatment2 Interventions
Novel vaccine formulation 2
Group X: C. difficile vaccine formulation 2, Schedule 1, (Phase 2)Experimental Treatment1 Intervention
Novel vaccine formulation 2
Group XI: C. difficile vaccine formulation 1, Schedule 4 (Phase 1)Experimental Treatment1 Intervention
Novel vaccine formulation 1
Group XII: C. difficile vaccine formulation 1, Schedule 2 (Phase 1)Experimental Treatment2 Interventions
Novel vaccine formulation 1
Group XIII: C difficile vaccine formulation 2, Schedule 1 (Phase 2)Experimental Treatment2 Interventions
Novel vaccine formulation 2
Group XIV: C. difficile vaccine (previously studied formulation) Schedule 1 (Phase 1)Active Control2 Interventions
Previously studied C. difficile vaccine formulation
Group XV: C. difficile vaccine (previously studied formulation) , Schedule 1 (Phase 2)Active Control2 Interventions
Previously studied C. difficile vaccine formulation
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
DBC Research USAPembroke Pines, FL
Research Centers of AmericaHollywood, FL
Miami Clinical ResearchMiami, FL
Great Lakes Clinical Trials - RavenswoodChicago, IL
More Trial Locations
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Who Is Running the Clinical Trial?
PfizerLead Sponsor