Brief Summary
The purpose of the study is to learn about how effective, safe, and tolerable the Clostridioides difficile (C. difficile) vaccine is in decreasing the number of C. difficile infections (pCDI) in adults 65 years of age or older.
The participants will receive either the C. difficile vaccine or placebo (saline). A placebo does not contain any active ingredients. The vaccines will be given as a shot into the upper arm muscle.
This study looks at the number of diarrhea (loose stools) events related to a C. difficile infection, so the length of the study can change. If these events happen quickly, the study may finish sooner; if they happen slowly, it could take longer. Sometimes, the study might stop early if the vaccine clearly works or clearly doesn't. Participants will stay in the study until enough events have occurred to answer the main question. On average, each person is expected to take part for up to about three and a half years.
During this time, participants will have 3 planned clinical visits and 3 planned phone visits. After these visits, more scheduled clinic visits will happen every year until the end of study.
Besides the scheduled study visits, if at any time during the study a participant has 3 or more loose stools in 24 hours, they will be asked to save the next one (the fourth or later) and contact the study site. The study site will check to see if it could be a C. difficile infection. This check may happen at the clinic or through a phone or video call.
The participants will receive either the C. difficile vaccine or placebo (saline). A placebo does not contain any active ingredients. The vaccines will be given as a shot into the upper arm muscle.
This study looks at the number of diarrhea (loose stools) events related to a C. difficile infection, so the length of the study can change. If these events happen quickly, the study may finish sooner; if they happen slowly, it could take longer. Sometimes, the study might stop early if the vaccine clearly works or clearly doesn't. Participants will stay in the study until enough events have occurred to answer the main question. On average, each person is expected to take part for up to about three and a half years.
During this time, participants will have 3 planned clinical visits and 3 planned phone visits. After these visits, more scheduled clinic visits will happen every year until the end of study.
Besides the scheduled study visits, if at any time during the study a participant has 3 or more loose stools in 24 hours, they will be asked to save the next one (the fourth or later) and contact the study site. The study site will check to see if it could be a C. difficile infection. This check may happen at the clinic or through a phone or video call.
Brief Title
A Study to Learn About a Clostridioides Difficile Vaccine in People 65 Years of Age and Older
Central Contacts
Central Contact Role
Contact
Central Contact Phone
1-800-718-1021
Central Contact Email
ClinicalTrials.gov_Inquiries@pfizer.com
Completion Date
Completion Date Type
Estimated
Conditions
Clostridioides Difficile Associated Disease
Eligibility Criteria
Who Can Join the Study (Inclusion Criteria):
• People with recent or future planned contact with healthcare systems or who have recently received antibiotics.
Who Cannot Join the Study (Exclusion Criteria):
* Anyone who has had CDI before.
* Anyone who has had surgery to remove part of their small or large intestine.
* Anyone who often has diarrhea (meaning three or more loose stools in a day, more than once a month).
* Anyone who has already received a vaccine or special antibody treatment for C. difficile.
* Anyone who has had a serious allergic reaction to a vaccine or to any part of the study vaccines.
* Anyone who might not respond well to the vaccine because their immune system is weak (either from a disease or from treatment).
* Anyone with cancer that has spread, kidney failure, or another serious health problem.
• People with recent or future planned contact with healthcare systems or who have recently received antibiotics.
Who Cannot Join the Study (Exclusion Criteria):
* Anyone who has had CDI before.
* Anyone who has had surgery to remove part of their small or large intestine.
* Anyone who often has diarrhea (meaning three or more loose stools in a day, more than once a month).
* Anyone who has already received a vaccine or special antibody treatment for C. difficile.
* Anyone who has had a serious allergic reaction to a vaccine or to any part of the study vaccines.
* Anyone who might not respond well to the vaccine because their immune system is weak (either from a disease or from treatment).
* Anyone with cancer that has spread, kidney failure, or another serious health problem.
Inclusion Criteria
Inclusion Criteria):
• People with recent or future planned contact with healthcare systems or who have recently received antibiotics.
Who Cannot Join the Study (
• People with recent or future planned contact with healthcare systems or who have recently received antibiotics.
Who Cannot Join the Study (
Gender
All
Gender Based
false
Healthy Volunteers
No
Last Update Post Date
Last Update Post Date Type
Actual
Last Update Submit Date
Minimum Age
65 Years
NCT Id
NCT07282665
Org Class
Industry
Org Full Name
Pfizer
Org Study Id
C4771002
Overall Status
Recruiting
Phases
Phase 3
Primary Completion Date
Primary Completion Date Type
Estimated
Official Title
A PHASE 3, PLACEBO-CONTROLLED, DOUBLE-BLINDED, RANDOMIZED STUDY TO EVALUATE THE EFFICACY, SAFETY, AND TOLERABILITY OF A CLOSTRIDIOIDES DIFFICILE VACCINE IN ADULTS 65 YEARS OF AGE AND OLDER
Primary Outcomes
Outcome Description
Injection site pain, redness, and swelling as self-reported in electronic diaries
Outcome Measure
The percentage of participants reporting local reactions
Outcome Time Frame
For 7 days after each vaccination
Outcome Description
Fever, vomiting, fatigue, headache, muscle pain, and joint pain as self-reported in electronic diaries
Outcome Measure
The percentage of participants reporting systemic events
Outcome Time Frame
For 7 days after each vaccination
Outcome Description
As elicited by investigator site staff
Outcome Measure
Percentage of participants reporting adverse events
Outcome Time Frame
From each vaccination through 1 month after each vaccination
Outcome Description
As elicited by investigator site staff
Outcome Measure
Percentage of participants reporting serious adverse events
Outcome Time Frame
From Vaccination 1 (Day 1) through 12 months after Vaccination 2 (last dose) (18 months)
Outcome Description
First episode of medically attended and clinically meaningful primary CDI incidence per 1000 person- years of follow- up
Outcome Measure
The incidence of the first episode of medically attended and clinically meaningful primary Clostridioides difficile infection (CDI)
Outcome Time Frame
from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Outcome Description
First episode of medically attended primary CDI incidence per 1000 person- years of follow- up
Outcome Measure
The incidence of the first episode of medically attended primary CDI
Outcome Time Frame
from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Outcome Description
First episode of clinically meaningful primary CDI incidence per 1000 person- years of follow- up
Outcome Measure
The incidence of the first episode of clinically meaningful primary CDI
Outcome Time Frame
from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Secondary Outcomes
Outcome Description
First episode of primary CDI with antibiotic use incidence per 1000 person- years of follow- up
Outcome Time Frame
from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Outcome Measure
The incidence of antibiotic use in the treatment of a first episode of the primary CDI
Outcome Description
First episode of severe or fulminant primary CDI incidence per 1000 person- years of follow- up
Outcome Time Frame
from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Outcome Measure
The incidence of severe primary CDI as defined by Infectious Diseases Society of America (IDSA)/ Society for Healthcare Epidemiology of America (SHEA)
Outcome Description
First episode of primary CDI incidence per 1000 person- years of follow- up
Outcome Time Frame
from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Outcome Measure
The incidence of a first episode of primary CDI (any severity)
Outcome Description
Time to all C.difficile infection cases
Outcome Time Frame
from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Outcome Measure
The incidence of all CDI (primary and recurrent)
See Also Links
Start Date
Start Date Type
Actual
Status Verified Date
First Post Date
First Post Date Type
Actual
First Submit Date
First Submit QC Date
Std Ages
Older Adult
Maximum Age Number (converted to Years and rounded down)
999
Minimum Age Number (converted to Years and rounded down)
65
Investigators
Investigator Type
Principal Investigator
Investigator Name
Barry Zingman
Investigator Email
bzingman@montefiore.org
Investigator Phone
718-920-2647
Investigator Department
Medicine
Investigator Division
Infectious Diseases
Investigator Sponsor Organization
Montefiore
Study Department
Medicine
Study Division
Infectious Diseases