Safety, Tolerability, and Immunogenicity Study of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Adults

Summary: The objective of the study is to evaluate the safety and tolerability of a single injection of VAX-24 at 3 dose levels compared to Prevnar 20™ (PCV20) in adults 18 to 49 years of age in Phase 1. The Phase 2 will evaluate the safety, tolerability, and immunogenicity of a single injection of VAX-24 at 3 dose levels compared to PCV20 in adults aged 50 to 64 years of age in Phase 2.
clinicaltrials.gov

Short title: Safety, Tolerability, and Immunogenicity Study of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Adults
clinicaltrials.gov

Official title: A Phase 1/2, Randomized, Observer-Blind, Dose-Finding, Controlled, Parallel-Group, Two-Stage Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Healthy Adults Aged 18 to 64 Years
clinicaltrials.gov

Control arm: Active comparator
clinicaltrials.gov

Registry reports results: Yes
clinicaltrials.gov

Listing at source: Listed
clinicaltrials.gov

Recruitment status: Completed
clinicaltrials.gov

Phase: Phase 1/Phase 2
clinicaltrials.gov

Study type: Interventional
clinicaltrials.gov

Completion date: 2023-01-10
clinicaltrials.gov

First posted: 2022-03-04
clinicaltrials.gov

Registry last updated: 2024-04-18
clinicaltrials.gov

Primary completion date: 2023-01-10
clinicaltrials.gov

Start date: 2022-02-22
clinicaltrials.gov

Actual participants: 835
clinicaltrials.gov

Participants: 835
clinicaltrials.gov

Participant count basis: Actual
clinicaltrials.gov

Protocol amendments: 4
clinicaltrials.gov

Number of sites: 13
clinicaltrials.gov

Data monitoring committee: Yes
clinicaltrials.gov

Registry sponsor category: Industry
clinicaltrials.gov

Lead sponsor: Vaxcyte, Inc.
clinicaltrials.gov

Source registry: ClinicalTrials.gov
clinicaltrials.gov

Registry ID: NCT05266456
clinicaltrials.gov

ClinicalTrials.gov ID: NCT05266456
clinicaltrials.gov

Registry record: Open registry record
clinicaltrials.gov

Allocation: Randomised
Model: Parallel groups
Purpose: Prevention
Masking: Quadruple masking
Masking description: Triple (Participant, Investigator, Outcomes Assessor)
Masked roles: Participants, Care providers, Investigators, Outcome assessors

Sources for study design

clinicaltrials.gov

Percentage of Participants Reporting Solicited Local Reactions Within 7 Days After Vaccination in Each Age Group
Timeframe: 7 days after vaccination
Solicited local reactions include redness/erythema, swelling/induration, and pain at injection site within 7 days after vaccination in each age group
Percentage of Participants Reporting Solicited Systemic Events Within 7 Days After Vaccination in Each Age Group
Timeframe: 7 days after vaccination
Solicited systemic reactions include fever, headache, fatigue, muscle pain, and joint pain
Percentage of Participants Reporting Unsolicited Adverse Events (AE) in Each Age Group
Timeframe: 1 month after vaccination
Percentage of participants in each age group with adverse events (AEs) whose date of onset occurs after the study vaccine and within the 28 days after vaccination.
Percentage of Participants Reporting SAEs and New Onset of Chronic Illnesses (NOCI)
Timeframe: 6 months after vaccination
Percentage of participants with SAEs and NOCIs

Percentage of Participants With Laboratory Value Abnormalities and/or Potentially Clinically Significant Laboratory Values
Timeframe: 1 month after vaccination
Shifts from Normal at Baseline to Abnormal on Day 29 in Clinical Chemistry Parameters Occurring in \>5% of Subjects Aged 50 to 64 Years
VAX-24 Pneumococcal Serotype-specific Opsonophagocytic Assay (OPA) Geometric Mean Titer (GMTs)
Timeframe: 1 month after vaccination
Antibody geometric mean titers as measured by OPA for the 24 pneumococcal serotypes in VAX-24
VAX-24 Pneumococcal Serotype-specific Immunoglobulin G (IgG) Geometric Mean Concentration (GMCs)
Timeframe: 1 month after vaccination
Antibody geometric mean concentrations as measured by IgG for the 24 pneumococcal serotypes in VAX-24

Sources for outcomes

clinicaltrials.gov

Sex: All
Age groups: Adults
Minimum age: 18 Years
Maximum age: 64 Years
Healthy volunteers: Yes

Male or female age 18 to 49 years (inclusive) for the Phase 1 group, or 50 to 64 years (inclusive) for the Phase 2 group at the time of enrollment into the study.
Able and willing to complete the informed consent process.
Available for clinical follow-up through the last study visit at 6 months after the study vaccination.
In good general health as determined by medical history, vital signs, physical examination, and clinical judgment of the investigator.
Screening laboratory values must be within the central laboratory normal limits prior to study enrollment. Minor abnormalities are considered acceptable if not clinically significant.
Willing to have blood samples collected, stored indefinitely, and used for research purposes.
Able to provide proof of identity to the satisfaction of the study staff completing the enrollment process.
Negative pregnancy test (urine and serum) for women of childbearing potential.

Previous pneumococcal disease (either confirmed or by self-reporting).
Previous receipt of a licensed or investigational pneumococcal vaccine.
Receipt of any investigational study product within 30 days prior to enrollment into the study, currently participating in another interventional investigational study, or having plans to receive another investigational product(s) while on study.
Planned or actual administration of any licensed vaccine during the period starting 30 days before enrollment into the study through Day 29.
Physical examination indicating any clinically significant medical condition.
Body Temperature > 38.0°C (> 100.4°F) or acute illness within 3 days prior to study vaccination (subject may be rescheduled).
Seropositive to HIV, HCV, or HBsAg.
History of severe allergic reaction with generalized urticaria, angioedema, or anaphylaxis.
Female who is breast-feeding or planning to become pregnant during study participation.
Bleeding disorder diagnosed by a doctor (eg, factor deficiency, coagulopathy, or platelet disorder requiring special precautions) or significant bruising or bleeding difficulties with IM injections or blood draws.
Any other chronic or clinically significant medical condition that, in the opinion of the investigator, would jeopardize the safety or rights of the subject or confound evaluation of the study vaccine.
Any medical, psychiatric, or social condition that, in the judgment of the investigator, is a contraindication to protocol participation or impairs a subject's ability to give informed consent.
Received blood or blood product (including Immune Globulin IV) within 90 days prior to enrollment into the study.
Received systemic corticosteroids for ≥ 14 consecutive days and has not completed treatment ≤30 days prior to enrollment into the study.
Receiving immunosuppressive therapy.
History of malignancy ≤5 years before enrollment, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer.