Safety and Immunogenicity of 20vPnC in Toddlers With 2 Prior Doses of Prevenar 13

Study Overview
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Brief Summary
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The purpose of this study is to understand the safety and effects of a study vaccine (20vPnC) in toddlers who had 2 prior doses of Prevnar 13. This study is being conducted in children who: are between 12 to 23 months of age; are healthy as determined by the study doctors; have received 2 doses of Prevnar 13 during the first year in life. Participants in this study will receive either 1 dose or 2 doses of the study vaccine or 1 dose of Prevnar 13 as a shot in the muscle. During the study, participants will have to come to the study clinic to receive the vaccines and have blood sample collected. The study team will work with participants' parents or legal guardians to monitor any unwanted reactions to the vaccines. Participants are expected to take part in this study for about 1 or 3 months, for 1 dose or 2 dose schedules, respectively.

Official Title
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A PHASE 3, RANDOMIZED, PARTIALLY DOUBLE-BLIND TRIAL TO EVALUATE THE SAFETY AND IMMUNOGENICITY OF 20-VALENT PNEUMOCOCCAL CONJUGATE VACCINE IN HEALTHY TODDLERS 12 THROUGH 23 MONTHS OF AGE WITH 2 PRIOR INFANT DOSES OF PREVENAR 13

Conditions
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Pneumococcal Disease

Intervention / Treatment
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* Biological: 20-valent pneumococcal conjugate vaccine
* Biological: 13-valent pneumococcal conjugate vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female toddlers ≥12 to <24 months of age at the time of consent Healthy toddlers determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study 2 infant doses of Prevenar 13 prior to 12 months of age Exclusion Criteria: History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) Major known congenital malformation or serious chronic disorder Other chronic medical or laboratory abnormality that may increase the risk associated with study participation or, in the investigator's judgment, make the participant inappropriate for the study. Previous vaccination with any investigational pneumococcal vaccine, or planned receipt through study participation

Ages Eligible for Study
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Minimum Age: 12 Months
Maximum Age: 23 Months

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: 2-Dose 20vPnC Group<br>Pneumococcal conjugate vaccine (2 doses approximately 2 months apart) | Biological: 20-valent pneumococcal conjugate vaccine<br>* 20-valent pneumococcal conjugate vaccine<br>|
| Experimental: 1-Dose 20vPnC Group<br>Pneumococcal conjugate vaccine | Biological: 20-valent pneumococcal conjugate vaccine<br>* 20-valent pneumococcal conjugate vaccine<br>|
| Active Comparator: 13vPnC Group<br>Pneumococcal conjugate vaccine | Biological: 13-valent pneumococcal conjugate vaccine<br>* 13-valent pneumococcal conjugate vaccine<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of participants reporting prompted local reactions within 7 days after the last assigned vaccination in each group | Prompted local reactions after the last assigned vaccination in each group | Day 7 | 
| Percentage of participants reporting prompted systemic events within 7 days after the last assigned vaccination in each group | Prompted systemic events after the last assigned vaccination in each group | Day 7 | 
| Percentage of participants reporting adverse events (AEs) within 1 month after the last assigned vaccination in each group | AEs occurring from last vaccination to 1 month after the last vaccination in each group | 1 month after the last vaccination | 
| Percentage of participants reporting serious adverse events (SAEs) within month after the last assigned vaccination in each group | SAEs occurring from last vaccination to 1 month after the last vaccination in each group | 1 month after the last vaccination | 
| Percentages of participants with predefined serotype-specific IgG concentrations for the 7 additional serotypes 1 month after the last assigned vaccination in each group | IgG concentrations 1 month after the last assigned vaccination | 1 month after the last vaccination | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Geometric mean concentrations (GMCs) of serotype-specific IgG concentrations 1 month after the last assigned vaccination in each group | IgG GMCs 1 month after the last assigned vaccination | 1 month after the last vaccination | 
| Percentages of participants with predefined serotype-specific IgG concentrations for the 13 matched serotypes 1 month after the last assigned vaccination in each group | IgG concentrations 1 month after the last assigned vaccination | 1 month after the last vaccination | 
| Opsonophagocytic activity (OPA) GMTs 1 month after the last assigned vaccination in each in group | OPA GMTs 1 month after the last assigned vaccination | 1 month after the last vaccination |