CompletedPhase 2

A Study To Investigate Two 3-dose Schedules Of A Clostridium Difficile Vaccine In Healthy Adults Aged 65 to 85 Years

United States300 participantsStarted 2015-07-16

Plain-language summary

This study will investigate a Clostridium difficile vaccine in healthy adults aged 65-85 years. Each subject will initially receive 3 doses of vaccine on 1 of 2 vaccination schedules. The study will assess the safety and tolerability of the vaccine as well as the subjects' immune response to the vaccine. One year after the third dose subjects that did not receive placebo will be randomized to receive a fourth dose. Subjects will be followed for up to 4 years after their third vaccination.

Who can participate

Age range

65 Years – 85 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Healthy male and female subjects * Aged 65 to 85 years Additional Inclusion Criteria for the extension Stage: * Receipt of all 3 doses of C difficile vaccine (100 µg or 200 µg antigen dose level) in the original portion of the study. Exclusion Criteria: * Proven or suspected prior episode of Clostridium difficile associated diarrhea * Unstable chronic medical condition * Disease requiring significant change in therapy or hospitalization for worsening disease within 8 weeks before receipt of study vaccine * Serious chronic disorders * Congenital or acquired immunodeficiency disorders * Rheumatologic disorders or other illnesses requiring chronic treatment with known immunosuppressant medications. * Active or treated leukemia or lymphoma or bone marrow disorder * Any contraindication to vaccination or vaccine components including previous anaphylactic reaction to any vaccine or vaccine-related components Additional Exclusion Criteria for the Extension Stage: * Subjects originally randomized to placebo during the original portion of the study. * Subjects who have already completed Visit 9 prior to study unblinding.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Day 1, 8 and 30 Regimen: Percentage of Participants Achieving Prespecified Antibody Titer Level for Toxin A at Day 37

Timeframe: Day 37 (7 days after Vaccination 3 of Day 1, 8 and 30 regimen)

Month 0, 1 and 6 Regimen: Percentage of Participants Achieving Prespecified Antibody Titer Level for Toxin A at Month 7

Timeframe: Month 7 (1 month after Vaccination 3 of Month 0, 1 and 6 regimen)

Day 1, 8 and 30 Regimen: Percentage of Participants Achieving Prespecified Antibody Titer Level for Toxin B at Day 37

Timeframe: Day 37 (7 days after Vaccination 3 of Day 1, 8 and 30 regimen)

Month 0, 1 and 6 Regimen: Percentage of Participants Achieving Prespecified Antibody Titer Level for Toxin B at Month 7

Timeframe: Month 7 (1 month after Vaccination 3 of Month 0, 1 and 6 regimen)

Day 1, 8 and 30 Regimen: Percentage of Participants Achieving Prespecified Antibody Titer Level for Both Toxin A and Toxin B at Day 37

Timeframe: Day 37 (7 days after Vaccination 3 of Day 1, 8 and 30 regimen)

Month 0, 1 and 6 Regimen: Percentage of Participants Achieving Prespecified Antibody Titer Level for Both Toxin A and Toxin B at Month 7

Trial details

NCT IDNCT02561195

SponsorPfizer

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2017-03-07

Results submitted2018-03-05

View on ClinicalTrials.gov More Clostridium Difficile Associated Disease trials