Clinical Trials List
Protocol NumberB5091007
NCT Number(ClinicalTrials.gov Identfier)NCT03090191
Completed
2017-03-23 - 2021-05-03
Phase III
Recruiting3
ICD-10A04.7
Enterocolitis due to Clostridium difficile
ICD-9008.45
Intestinal infections due to Clostridium difficile
A PHASE 3, PLACEBO-CONTROLLED, RANDOMIZED, OBSERVER-BLINDED STUDY TO EVALUATE THE EFFICACY, SAFETY, AND TOLERABILITY OF A CLOSTRIDIUM DIFFICILE VACCINE IN ADULTS 50 YEARS OF AGE AND OLDER
-
Sponsor
Pfizer, Inc.
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Trial scale
Multi-Regional Multi-Center
-
Update
2026/02/01
Investigators and Locations
Co-Principal Investigator
The Actual Total Number of Participants Enrolled
0 Recruiting
The Actual Total Number of Participants Enrolled
0 Recruiting
Co-Principal Investigator
- HSIN-YUN SUN Division of General Internal Medicine
- 陳抱宇 Division of General Surgery
- 鄭琬豑 Division of General Internal Medicine
- SUNG-CHING PAN Division of General Internal Medicine
The Actual Total Number of Participants Enrolled
0 Recruiting
Audit
None
Condition/Disease
Clostridium Difficile Infection
Objectives
The Clover trial is evaluating an investigational vaccine that may help to prevent Clostridium difficile infection. Participants in the study are adults 50 years of age and older, who are at risk of developing Clostridium difficile infection. The study will assess whether the vaccine prevents the disease, and whether it is safe and well tolerated.
Each subject will receive 3 doses of Clostridium difficile vaccine or placebo and be followed for up to 3 years after vaccination for potential Clostridium difficile infection.
Test Drug
PF-06425090 (Clostridium difficile vaccine)
Active Ingredient
PF-06425090 (Clostridium difficile vaccine)
Dosage Form
Vial
Dosage
200 mcg powder
Endpoints
Primary Outcome Measures :
First primary case CDI incidence [ Time Frame: Up to 3 years after the 3rd dose ]
Per 1000 person-years of follow-up (confirmed at the central laboratory)
First primary case CDI incidence [ Time Frame: Up to 3.4 years after the 2nd dose ]
Per 1000 person-years of follow-up (confirmed at the central laboratory)
Percentage of subjects reporting local reactions [ Time Frame: Up to 7 days following each vaccination, 1, 2, and 3 ]
Pain, erythema, and induration, as self-reported on electronic diaries
Percentage of subjects reporting systemic events [ Time Frame: Up to 7 days following each vaccination, 1, 2, and 3 ]
Fever, vomiting, headache, fatigue, new or worsening muscle pain, and new or worsening joint pain, as self-reported on electronic diaries
Percentage of subjects reporting nonserious adverse events [ Time Frame: Up to 7 months after the first dose ]
As elicited by investigational site staff
Percentage of subjects reporting serious adverse events [ Time Frame: Up to 12 months after the first dose ]
As elicited by investigational site staff
First primary case CDI incidence [ Time Frame: Up to 3 years after the 3rd dose ]
Per 1000 person-years of follow-up (confirmed at the central laboratory)
First primary case CDI incidence [ Time Frame: Up to 3.4 years after the 2nd dose ]
Per 1000 person-years of follow-up (confirmed at the central laboratory)
Percentage of subjects reporting local reactions [ Time Frame: Up to 7 days following each vaccination, 1, 2, and 3 ]
Pain, erythema, and induration, as self-reported on electronic diaries
Percentage of subjects reporting systemic events [ Time Frame: Up to 7 days following each vaccination, 1, 2, and 3 ]
Fever, vomiting, headache, fatigue, new or worsening muscle pain, and new or worsening joint pain, as self-reported on electronic diaries
Percentage of subjects reporting nonserious adverse events [ Time Frame: Up to 7 months after the first dose ]
As elicited by investigational site staff
Percentage of subjects reporting serious adverse events [ Time Frame: Up to 12 months after the first dose ]
As elicited by investigational site staff
Inclution Criteria
Inclusion Criteria
Subjects must meet all of the following inclusion criteria to be eligible for enrollment into the
study:
1. Evidence of a personally signed and dated ICD indicating that the subject has been
informed of all pertinent aspects of the study.
2. Willing and able to comply with scheduled visits, vaccination plan, and other study
procedures.
3. 50 Years or older at enrollment.
4. Subjects with an increased risk of future contact with healthcare systems by virtue of:
At least 1 inpatient hospitalization 2 nights’ duration in the previous 12 months; or
At least 2 emergency room visits in the previous 12 months; or
At least 10 outpatient visits (primary and/or secondary care visits but excluding
pharmacy and mental health visits) in the previous 12 months; or
Residence in a skilled nursing facility (a residential institution that provides
professional nursing care and rehabilitation services, usually following discharge
from the hospital); or
Residence in a nursing home (a residential institution that provides assistance with
activities of daily living); or
Inpatient hospitalization 2 nights’ duration scheduled 37 days after randomization.
Or subjects who have received systemic (ie, oral or injected) antibiotics at any time in the
previous 12 weeks.
5. Ability to be contacted by telephone during study participation.
6. Negative urine pregnancy test for female subjects of childbearing potential.
Female subjects of nonchildbearing potential must meet at least 1 of the following
criteria:
a. Achieved postmenopausal status, defined as follows: cessation of regular menses for
at least 12 consecutive months with no alternative pathological or physiological
cause; status may be confirmed with a serum follicle-stimulating hormone (FSH)
level confirming the postmenopausal state;
b. Have undergone a documented hysterectomy and/or bilateral oophorectomy;
c. Have medically confirmed ovarian failure.
All other female subjects (including female subjects with tubal ligations) are considered
to be of childbearing potential.
Subjects must meet all of the following inclusion criteria to be eligible for enrollment into the
study:
1. Evidence of a personally signed and dated ICD indicating that the subject has been
informed of all pertinent aspects of the study.
2. Willing and able to comply with scheduled visits, vaccination plan, and other study
procedures.
3. 50 Years or older at enrollment.
4. Subjects with an increased risk of future contact with healthcare systems by virtue of:
At least 1 inpatient hospitalization 2 nights’ duration in the previous 12 months; or
At least 2 emergency room visits in the previous 12 months; or
At least 10 outpatient visits (primary and/or secondary care visits but excluding
pharmacy and mental health visits) in the previous 12 months; or
Residence in a skilled nursing facility (a residential institution that provides
professional nursing care and rehabilitation services, usually following discharge
from the hospital); or
Residence in a nursing home (a residential institution that provides assistance with
activities of daily living); or
Inpatient hospitalization 2 nights’ duration scheduled 37 days after randomization.
Or subjects who have received systemic (ie, oral or injected) antibiotics at any time in the
previous 12 weeks.
5. Ability to be contacted by telephone during study participation.
6. Negative urine pregnancy test for female subjects of childbearing potential.
Female subjects of nonchildbearing potential must meet at least 1 of the following
criteria:
a. Achieved postmenopausal status, defined as follows: cessation of regular menses for
at least 12 consecutive months with no alternative pathological or physiological
cause; status may be confirmed with a serum follicle-stimulating hormone (FSH)
level confirming the postmenopausal state;
b. Have undergone a documented hysterectomy and/or bilateral oophorectomy;
c. Have medically confirmed ovarian failure.
All other female subjects (including female subjects with tubal ligations) are considered
to be of childbearing potential.
Exclusion Criteria
Exclusion Criteria
Subjects with any of the following characteristics/conditions will not be included in the
study:
1. Investigator site staff members directly involved in the conduct of the study and their
family members, site staff members otherwise supervised by the investigator, or subjects
who are Pfizer employees, including their family members, directly involved in the
conduct of the study.
2. Participation in other studies involving investigational drug(s)/vaccine(s) within 28 days
prior to study entry until Visit 5 (1 month after the third vaccination).
3. Previous administration of an investigational C difficile vaccine or C difficile mAb
therapy.
4. Prior episode of CDI, confirmed by either laboratory test or diagnosis of
pseudomembranous colitis at colonoscopy, at surgery, or histopathologically.
5. Receipt of blood products or immunoglobulins within 6 months before enrollment.
6. Subjects who may be unable to respond to vaccination due to:
Metastatic malignancy; or
End-stage renal disease (glomerular filtration rate <15 mL/min/1.73 m
2
or on
dialysis); or
Any serious medical disorder that in the investigator’s opinion is likely to be fatal
within the next 12 months; or
Congenital or acquired immunodeficiency; or
Receipt of systemic corticosteroids (20 mg/day of prednisone or equivalent) for 14
days within 28 days of enrollment; or
Receipt of chronic systemic treatment with other known immunosuppressant
medications, or radiotherapy, within 6 months of enrollment.
7. Known infection with human immunodeficiency virus (HIV).
8. Any bleeding disorder or anticoagulant therapy that would contraindicate intramuscular
injection.
9. Any contraindication to vaccination or vaccine components, including previous
anaphylactic reaction to any vaccine or vaccine-related components.
10. Prior small- or large-bowel resection (does not include appendectomy).
11. Any condition or treatment resulting in frequent diarrhea (3 loose stools per day more
than once per month), as reported by the subject.
12. Other acute or chronic medical or psychiatric condition including recent (within the past
year) or active suicidal ideation or behavioral or laboratory abnormality that may increase
the risk associated with study participation or investigational product administration or
may interfere with the interpretation of study results and, in the judgment of the
investigator, would make the subject inappropriate for entry into this study.
13. Pregnant female subjects; breastfeeding female subjects; fertile male subjects and female
subjects of childbearing potential who are, in the opinion of the investigator, sexually
active and at risk for pregnancy with their partner(s) and are unwilling or unable to use 2
highly effective methods of contraception as outlined in this protocol from the signing of
the informed consent until at least 28 days after the last dose of investigational product.
Subjects with any of the following characteristics/conditions will not be included in the
study:
1. Investigator site staff members directly involved in the conduct of the study and their
family members, site staff members otherwise supervised by the investigator, or subjects
who are Pfizer employees, including their family members, directly involved in the
conduct of the study.
2. Participation in other studies involving investigational drug(s)/vaccine(s) within 28 days
prior to study entry until Visit 5 (1 month after the third vaccination).
3. Previous administration of an investigational C difficile vaccine or C difficile mAb
therapy.
4. Prior episode of CDI, confirmed by either laboratory test or diagnosis of
pseudomembranous colitis at colonoscopy, at surgery, or histopathologically.
5. Receipt of blood products or immunoglobulins within 6 months before enrollment.
6. Subjects who may be unable to respond to vaccination due to:
Metastatic malignancy; or
End-stage renal disease (glomerular filtration rate <15 mL/min/1.73 m
2
or on
dialysis); or
Any serious medical disorder that in the investigator’s opinion is likely to be fatal
within the next 12 months; or
Congenital or acquired immunodeficiency; or
Receipt of systemic corticosteroids (20 mg/day of prednisone or equivalent) for 14
days within 28 days of enrollment; or
Receipt of chronic systemic treatment with other known immunosuppressant
medications, or radiotherapy, within 6 months of enrollment.
7. Known infection with human immunodeficiency virus (HIV).
8. Any bleeding disorder or anticoagulant therapy that would contraindicate intramuscular
injection.
9. Any contraindication to vaccination or vaccine components, including previous
anaphylactic reaction to any vaccine or vaccine-related components.
10. Prior small- or large-bowel resection (does not include appendectomy).
11. Any condition or treatment resulting in frequent diarrhea (3 loose stools per day more
than once per month), as reported by the subject.
12. Other acute or chronic medical or psychiatric condition including recent (within the past
year) or active suicidal ideation or behavioral or laboratory abnormality that may increase
the risk associated with study participation or investigational product administration or
may interfere with the interpretation of study results and, in the judgment of the
investigator, would make the subject inappropriate for entry into this study.
13. Pregnant female subjects; breastfeeding female subjects; fertile male subjects and female
subjects of childbearing potential who are, in the opinion of the investigator, sexually
active and at risk for pregnancy with their partner(s) and are unwilling or unable to use 2
highly effective methods of contraception as outlined in this protocol from the signing of
the informed consent until at least 28 days after the last dose of investigational product.
The Estimated Number of Participants
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Taiwan
129 participants
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Global
16000 participants
