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Evaluation of a Single Vaccination of One of Three Ascending Dose Levels of a 4-Antigen Staphylococcus Aureus Vaccine (SA4Ag) and a Single Dose Level of a 3-Antigen Staphylococcus Aureus Vaccine (SA3Ag) in Healthy Adults Aged 65 to <86 Years

A Phase 1/2 Placebo-controlled, Randomized, Double-blind Trial To Evaluate The Safety, Tolerability, And Immunogenicity Of 3 Ascending Dose Levels Of A 4-antigen Staphylococcus Aureus Vaccine (sa4ag) And A Single Dose Level Of A 3-antigen Staphylococcus Aureus Vaccine (sa3ag) In Healthy Adults Aged 65 To <86 Years

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01643941
Enrollment
284
Registered
2012-07-18
Start date
2012-08-31
Completion date
2014-03-31
Last updated
2019-03-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Staphylococcal Infections

Keywords

Staphylococcus aureus, vaccine, Staphylococcal infection

Brief summary

This is a Phase 1 and Phase 2 study of a single vaccination with one of three dose levels of a 4-antigen investigational vaccine against Staphylococcus aureus (SA4Ag) and a single dose level of a 3-antigen Staphylococcus aureus vaccine (SA3Ag). The main goal of the study is to determine how safe and well tolerated the vaccine is as well as to describe the immune response elicited by the vaccine in healthy adults aged 65 to \<86 years. In addition, the study aims to assess the effect of the Staphylococcus aureus vaccine on the presence of the Staphylococcus aureus within the nose, throat and perineal skin of healthy adults aged 65 to \<86 years.

Interventions

Subjects receive 1 intramuscular injection (0.5 mL) of the low dose level of the SA4Ag vaccine.

PROCEDUREBlood draw

Blood for HIV, HBV and HCV screening will be collected prior to enrollment for Phase 1 subjects. Blood for hematology, coagulation and blood chemistry will be collected at a minimum of 3 timepoints from Phase 1 subjects. Blood for immunogenicity will be collected from all subjects at various timepoints.

Colonization swabs will be collected from all subjects at various timepoints.

Subjects receive 1 intramuscular injection (0.5 mL) of the mid dose level of the SA4Ag vaccine.

Subjects receive 1 intramuscular injection (0.5 mL) of the high dose level of the SA4Ag vaccine.

BIOLOGICALSA3Ag vaccine

Phase 2 only: Subjects receive 1 intramuscular injection (0.5 mL) of the mid dose level of the SA3Ag vaccine.

PROCEDUREBlood sample

Blood for immunogenicity will be collected from all subjects at various timepoints.

BIOLOGICALPlacebo

Subjects receive one intramuscular injection (0.5 mL) of placebo which contains excipients of the vaccine formulation minus the active ingredients.

Colonization swabs will be collected from all subjects at various timepoints.

Sponsors

Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
65 Years to 85 Years
Healthy volunteers
Yes

Inclusion criteria

* Healthy males and healthy postmenopausal females, aged 65 to \<86 years at enrollment, as determined by medical history, physical examination, and the clinical judgment of the investigator to be eligible for the study. Subjects with preexisting chronic medical conditions determined to be stable may be included. * Available for the entire duration of the study, and able to comply with scheduled visits, study plan, laboratory tests, and other study procedures including completion of the electronic diary (e diary) from Day 1 to Day 14 following vaccination. * Able to be contacted by telephone during study participation. * Male subjects who, in the opinion of the investigator, are biologically capable of fathering children, and who are sexually active with women of childbearing potential must agree to use a highly effective method of contraception throughout the study.

Exclusion criteria

* Unstable chronic medical condition or disease requiring significant change in therapy or hospitalization for worsening disease within 3 months before receipt of study vaccine. * Serious chronic medical disorders or any disorder that in the investigator's opinion precludes the subject from participating in the study. * Donation of blood volume of 250 mL or greater or donation of plasma within 3 months prior to enrollment through conclusion of the study. * Bleeding condition associated with prolonged bleeding time that may contraindicate intramuscular injection or blood draw including subjects taking anticoagulant, antiplatelet and/or antithrombotic agents except for low-dose daily aspirin within 30 days before enrollment through completion of Visit 6 (Day 29). * Any contraindication to vaccination or vaccine components, including previous anaphylactic reaction to any vaccine or vaccine related components. * Immunocompromised persons or subjects currently on immunosuppressive therapy or with a history of immunosuppressive therapy. History of immune-modifying drugs. * Previous administration of S. aureus vaccination. * Any infection proven or suspected to be caused by S. aureus within 6 months preceding study vaccination. * Receipt of blood products or immunoglobulins (including monoclonal antibodies) within 12 months before enrollment through conclusion of the study. * Participation in other investigational or interventional studies within 30 days before the current study begins and/or during study participation. Participation in purely observational studies is acceptable. * Subjects who are investigational site staff members or subjects who are immediate family members (first-degree relatives) of investigational site staff members or Pfizer employees directly involved in the conduct of the trial. * Residence in a nursing home or long-term care facility or requirement for semiskilled nursing care. An ambulatory subject who is a resident of a retirement home or village is eligible for the trial. * A Mini-Mental State Examination (MMSE) score of ≤21. * For Phase 1 subjects only, any abnormality in screening hematology, coagulation, and/or blood chemistry laboratory values except as noted in protocol * Subjects with known active disease with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and/or hepatitis C virus (HCV), or Phase 1 subjects with a positive screening test for HIV, HBV and/or HCV. * Other severe acute or chronic medical or psychiatric condition 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. * Planned surgical procedure within 30 days following vaccination.

Design outcomes

Primary

MeasureTime frame
Number and proportion of subjects reporting solicited local reactions (size of redness and/or swelling and severity of pain at the injection site) and severity of the local reactions as self-reported on electronic diaries (e-diaries)14 days
Number and proportion of subjects reporting solicited systemic events (fever, vomiting, diarrhea, headache, fatigue, new or worsening muscle pain, new or worsening joint pain) and severity of solicited systemic events self-reported on electronic diaries14 days
Number and proportion of subjects reporting unsolicited AEs and serious adverse events (SAEs) categorized according to the Medical Dictionary for Regulatory Activities (MedDRA)1 month (AEs); 6 months (SAEs)
Number and proportion of Phase 1 subjects with abnormal hematology, coagulation and blood chemistry lab assessments14 days
Number and proportion of Phase 1 subjects with grading shifts in hematology, coagulation and blood chemistry laboratory assessments14 days
Proportion of subjects achieving antibody responses to specific vaccine components with results ≥ thresholds defined for each vaccine component based on immunoglobulin-binding and/or opsonphagocytic activity assays1 month

Secondary

MeasureTime frame
Immunoglobulin titers measured as geometric mean titers for each antigen at each applicable blood sampling time point, as measured by antigen-specific antibody levels using an immunoglobulin binding assay.various, up to 12 months
Proportion of subjects with ≥2-fold, ≥4-fold, ≥8-fold, ≥16-fold, and ≥32-fold increase in opsonophagocytic activity titers against S. aureus isolates from baseline to each applicable visit after vaccination.Various, up to 12 months
Opsonophagocytic activity titers measured as geometric mean titers against S. aureus isolates at each applicable blood sampling time point.various, up to 12 months
Immunoglobulin geometric mean fold rise for each of the vaccine components as measured by antigen-specific antibody levels using an immunoglobulin binding assay.1 month
Geometric mean fold rise on opsonophagocytic activity assay titers against S. aureus isolates.1 month
Proportion of subjects achieving antibody responses to specific antigens with results ≥ thresholds defined for each vaccine component at each applicable visit.Various, up to 12 months
Proportion of subjects with ≥2-fold, ≥4-fold, ≥8-fold, ≥16-fold, and ≥32-fold increase in immunoglobulin titers from baseline to each applicable visit after vaccination for each antigen.Various, up to 12 months

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 28, 2026