Overview

This trial is active, not recruiting.

Condition clostridium difficile associated disease
Treatments clostridium difficile vaccine, placebo
Phase phase 2
Sponsor Pfizer
Start date July 2015
End date April 2017
Trial size 854 participants
Trial identifier NCT02561195, B5091009

Summary

This study will investigate a Clostridium difficile vaccine in healthy adults aged 65-85 years. Each subject will 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.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Allocation randomized
Endpoint classification safety study
Intervention model parallel assignment
Masking double blind (subject, investigator, outcomes assessor)
Primary purpose prevention
Arm
(Experimental)
clostridium difficile vaccine
0.5 mL intramuscular injection.
(Experimental)
clostridium difficile vaccine
0.5 mL intramuscular injection.
(Placebo Comparator)
placebo
0.5 mL intramuscular injection
(Experimental)
clostridium difficile vaccine
0.5 mL intramuscular injection.
(Experimental)
clostridium difficile vaccine
0.5 mL intramuscular injection.
(Placebo Comparator)
placebo
0.5 mL intramuscular injection

Primary Outcomes

Measure
Proportions of subjects in each vaccine group with toxin A- specific neutralizing antibody level greater than or equal to the specified threshold for toxin A.
time frame: 7 days or 1 month after dose 3
Proportions of subjects in each vaccine group with toxin B- specific neutralizing antibody level greater than or equal to the specified threshold for toxin B.
time frame: 7 days or 1 month after dose 3
Proportions of subjects in each vaccine group with both toxin A- toxin B- specific neutralizing antibody level greater than or equal to the specified threshold for toxin A- and toxin B, respectively.
time frame: 7 days or 1 month after dose 3
Proportions of subjects reporting local reactions (pain, erythema, and induration) and their severity, as self-reported on e-diaries.
time frame: Up to 14 days after each vaccination
Proportions of subjects reporting systemic events (fever, vomiting, diarrhea, headache, fatigue, new or worsening muscle pain and new or worsening joint pain) and their severity, as self-reported on e-diaries.
time frame: Up to 14 days after each vaccination
Proportions of subjects reporting AEs (categorized according to the Medical Dictionary for Regulatory Activities [MedDRA]).
time frame: From the first vaccination up to 28 days after the last vaccination.
Proportions of subjects reporting SAEs (categorized according to the Medical Dictionary for Regulatory Activities [MedDRA]).
time frame: From the first vaccination until 6 months after the last vaccination.

Secondary Outcomes

Measure
Toxin A- and toxin B-specific neutralizing antibody levels, expressed as geometric mean concentrations.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Geometric mean fold rises in toxin A-specific neutralizing antibody levels.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Geometric mean fold rises in toxin B-specific neutralizing antibody levels.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Geometric mean fold rises in both toxin A- and toxin B-specific neutralizing antibody levels.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Proportions of subjects in each vaccine group with fold rises in toxin A-specific neutralizing antibody levels.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Proportions of subjects in each vaccine group with fold rises in toxin B-specific neutralizing antibody levels.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Proportions of subjects in each vaccine group with fold rises in both toxin A- and toxin B-specific neutralizing antibody levels.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Proportions of subjects in each vaccine group with toxin A- specific neutralizing antibody level greater than or equal to the specified threshold for toxin A.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Proportions of subjects in each vaccine group with toxin B- specific neutralizing antibody level greater than or equal to the specified threshold for toxin B.
time frame: At multiple timepoints during the study up to 12 months after dose 3
Proportions of subjects in each vaccine group with both toxin A- toxin B- specific neutralizing antibody level greater than or equal to the specified threshold for toxin A- and toxin B, respectively.
time frame: At multiple timepoints during the study up to 12 months after dose 3

Eligibility Criteria

Male or female participants from 65 years up to 85 years old.

Inclusion Criteria: - Healthy male and female subjects - Aged 65 to 85 years 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 Information

Official title A Phase 2, Placebo-controlled, Randomized, Observer-blinded Study To Evaluate The Safety, Tolerability, And Immunogenicity Of Two 3-dose Regimens Of A Clostridium Difficile Vaccine In Healthy Adults Aged 65 To 85 Years
Trial information was received from ClinicalTrials.gov and was last updated in August 2016.
Information provided to ClinicalTrials.gov by Pfizer.