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

Study Overview
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Brief Summary
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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 65 years of age and older.

Official Title
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A Phase 2, Randomized, Observer-Blind, Dose-Finding, Controlled Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Healthy Adults 65 Years and Older

Conditions
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Pneumococcal Vaccines

Intervention / Treatment
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* Biological: 24-Valent Pneumococcal Conjugate Vaccine
* Biological: Pneumococcal 20-valent Conjugate Vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female age 65 or older. 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. Preexisting medical conditions must be stable as defined by no change in treatment at least 6 weeks prior to study participation. 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. Exclusion Criteria: 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). Previous or existing diagnosis of HIV, Hepatitis B or Hepatitis C. History of severe allergic reaction with generalized urticaria, angioedema, or anaphylaxis. 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.

Ages Eligible for Study
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Minimum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 1<br>Participants will receive a single dose of VAX-24 administered as an intramuscular injection on Day 1 at one of three dose levels. | Biological: 24-Valent Pneumococcal Conjugate Vaccine<br>* 0.5 ml dose of VAX-24 will be administered into the deltoid muscle at Day 1<br>|
| Experimental: Group 2<br>Participants will receive a single dose of VAX-24 administered as an intramuscular injection on Day 1 at one of three dose levels. | Biological: 24-Valent Pneumococcal Conjugate Vaccine<br>* 0.5 ml dose of VAX-24 will be administered into the deltoid muscle at Day 1<br>|
| Experimental: Group 3<br>Participants will receive a single dose of VAX-24 administered as an intramuscular injection on Day 1 at one of three dose levels. | Biological: 24-Valent Pneumococcal Conjugate Vaccine<br>* 0.5 ml dose of VAX-24 will be administered into the deltoid muscle at Day 1<br>|
| Active Comparator: Group 4<br>Participants will receive a single intramuscular injection of the standard dose of PCV20 on Day 1. | Biological: Pneumococcal 20-valent Conjugate Vaccine<br>* 0.5 ml dose of Prevnar 20 will be administered into the deltoid muscle at Day 1<br>* Other names: Prevnar 20, PCV20;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of participants reporting solicited local reactions within 7 days after vaccination | Solicited local reactions included redness/erythema, swelling/induration, and pain at injection site | 7 days after vaccination | 
| Percentage of participants reporting solicited systemic events within 7 days after vaccination | Solicited systemic reactions include fever, headache, fatigue, muscle pain, and joint pain | 7 days after vaccination | 
| Percentage of subjects reporting unsolicited adverse events within 1 month after vaccination | Percentage of participants with adverse events and serious adverse events (SAEs) | 1 month after vaccination | 
| Percentage of participants reporting SAEs and new onset of chronic illnesses (NOCIs) | Percentage of participants with SAEs and NOCIs | 6 months after vaccination | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24 VAX-24 Pneumococcal serotype-specific opsonophagocytic assay (OPA) geometric mean titer (GMTs) | Antibody geometric mean titers as measured by OPA for the 24 pneumococcal serotypes in VAX-24 | 1 month after vaccination | 
| 24 VAX-24 Pneumococcal serotype-specific IgG geometric mean concentration (GMCs) | Antibody geometric mean concentrations as measured by IgG for the 24 pneumococcal serotypes in VAX-24 | 1 month after vaccination |