A Phase 2 Study to Learn About a Monovalent Pneumococcal Conjugate Candidate in Healthy Toddlers

A Phase 2, Randomized, Open-Label Trial to Describe the Safety and Immunogenicity of a Monovalent Pneumococcal Conjugate Candidate Administered As a 2-Dose Series in Healthy Toddlers 11 Through 15 Months of Age Who Previously Received the PCV10 Primary Series

The purpose of the study is to learn about the effects of a monovalent (single component) pneumococcal conjugate candidate (mPnC candidate) when given to toddlers between 11 and 15 months of age.

All participants in this study will receive 2 doses of either mPnC candidate or mPnC control at the clinic approximately 8 weeks apart. All participants will also receive their third (toddler) dose of PCV10 at Visit 1.

Study Overview

• Status: Completed
• Conditions: Healthy Participants
• Intervention / Treatment: Biological: mPnC candidate; Biological: mPnC control

• Study Type: Interventional
• Enrollment (Actual): 105
• Phase: Phase 2

Contacts and Locations

Study Locations

• Finland
  • Mellersta Österbotten
    • Kokkola, Mellersta Österbotten, Finland, 67100
      • FVR, Kokkolan rokotetutkimusklinikka
  • Pirkanmaa
    • Tampere, Pirkanmaa, Finland, 33100
      • FVR, Tampereen rokotetutkimusklinikka
  • Pohjois-pohjanmaa
    • Oulu, Pohjois-pohjanmaa, Finland, 90220
      • FVR, Oulun rokotetutkimusklinikka
  • Södra Österbotten
    • Seinäjoki, Södra Österbotten, Finland, 60100
      • FVR, Seinäjoen rokotetutkimusklinikka
  • Uusimaa
    • Espoo, Uusimaa, Finland, 02230
      • FVR, Espoon rokotetutkimusklinikka
    • Helsinki, Uusimaa, Finland, 00100
      • FVR, Etelä-Helsingin rokotetutkimusklinikka
    • Helsinki, Uusimaa, Finland, 00290
      • MeVac - Meilahti Vaccine Research Center
    • Järvenpää, Uusimaa, Finland, 04400
      • FVR, Järvenpään rokotetutkimusklinikka
  • Varsinais-suomi
    • Turku, Varsinais-suomi, Finland, 20520
      • FVR, Turun rokotetutkimusklinikka
• Poland
  • Kujawsko-pomorskie
    • Bydgoszcz, Kujawsko-pomorskie, Poland, 85-796
      • Centrum medyczne Pratia Bydgoszcz
  • Lubelskie
    • Lublin, Lubelskie, Poland, 20-044
      • NZOZ Praktyka Lekarza Rodzinnego "ESKULAP"

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Key Inclusion Criteria:

• Toddlers ≥11 to ≤15 months of age at the time of consent.
• Have received exactly 2 infant doses of PCV10 according to a local immunization schedule.
• Healthy toddlers determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study.

Key Exclusion Criteria:

• History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of study intervention, 13vPnC, 20vPnC, or any diphtheria toxoid-containing vaccine.
• significant neurological disorder or history of seizure (excluding febrile seizure) or significant stable or evolving disorders such as cerebral palsy, encephalopathy, hydrocephalus, or other significant disorders.
• Major known congenital malformation or serious chronic disorder.
• History of microbiologically proven invasive disease caused by S pneumoniae.
• Previous vaccination with any licensed pneumococcal vaccine (other than the PCV10 primary infant series) or investigational pneumococcal vaccine, or planned receipt of nonstudy pneumococcal vaccine during study participation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: mPnC candidate; Participants will receive the mPnC candidate at Visit 1 and Visit 3 (approximately 8 weeks apart). PCV10 will also be given at Visit 1.	Biological: mPnC candidate; monovalent pneumococcal conjugate candidate
Active Comparator: mPnC control; Participants will receive the mPnC control at Visit 1 and Visit 3 (approximately 8 weeks apart). PCV10 will also be given at Visit 1.	Biological: mPnC control; monovalent pneumococcal conjugate control

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants With Local Reactions Within 7 Days After Dose 1	Local reactions included redness, swelling and pain at injection site. Redness and swelling were graded as mild: > 0 to 2.0 centimeter (cm), moderate: >2.0 to 7.0 cm, severe: >7.0 cm and Grade 4: necrosis or exfoliative dermatitis (redness) and necrosis (swelling). Pain at injection site was graded as mild: hurt if gently touched, moderate: hurt if gently touched, with crying, severe: caused limitation of limb movement and Grade 4 (potentially life threatening): emergency room visit or hospitalization for severe pain at injection site. Grade 4 assessments were made by the investigator. Any local reaction: any mild, moderate, severe, or Grade 4 redness, swelling, or pain at the injection site.	Day 1 through Day 7, where Day 1 is the day of Dose 1 administration (Visit 1 of study)
Percentage of Participants With Local Reactions Within 7 Days After Dose 2	Local reactions included redness, swelling and pain at injection site. Redness and swelling were graded as mild: > 0 to 2.0 cm, moderate: >2.0 to 7.0 cm, severe: >7.0 cm and Grade 4: necrosis or exfoliative dermatitis (redness) and necrosis (swelling). Pain at injection site was graded as mild: hurt if gently touched, moderate: hurt if gently touched, with crying, severe: caused limitation of limb movement and Grade 4 (potentially life threatening): emergency room visit or hospitalization for severe pain at injection site. Grade 4 assessments were made by the investigator. Any local reaction: any mild, moderate, severe, or Grade 4 redness, swelling, or pain at the injection site.	Day 1 through Day 7, where Day 1 is the day of Dose 2 administration (Visit 3 of study)
Percentage of Participants With Systemic Events Within 7 Days After Dose 1	Fever (oral temperature >= 38 degree Celsius [degC]) was categorized as >=38.0-38.4 degC, >38.4-38.9 degC, >38.9-40.0 degC and >40.0 degC. Decreased appetite was graded as mild: decreased interest in eating, moderate: decreased oral intake, severe: refusal to feed. Drowsiness was graded as mild: increased/prolonged sleeping bouts, moderate: slightly subdued, interfered daily activity, severe: disabled, not interested in daily activity. Irritability was graded as mild: easily consolable, moderate: required increased attention, severe: inconsolable, crying couldn't be comforted. Grade 4 decreased appetite, drowsiness and irritability events led to emergency room visit or hospitalization and were classified by investigator/medically qualified person. Any systemic event: any fever, decreased appetite, drowsiness, irritability.	Day 1 through Day 7, where Day 1 is the day of Dose 1 administration (Visit 1 of study)
Percentage of Participants With Systemic Events Within 7 Days After Dose 2	Fever (oral temperature >= 38 degC) was categorized as >=38.0-38.4 degC, >38.4-38.9 degC, >38.9-40.0 degC and >40.0 degC. Decreased appetite was graded as mild: decreased interest in eating, moderate: decreased oral intake, severe: refusal to feed. Drowsiness was graded as mild: increased/prolonged sleeping bouts, moderate: slightly subdued, interfered daily activity, severe: disabled, not interested in daily activity. Irritability was graded as mild: easily consolable, moderate: required increased attention, severe: inconsolable, crying couldn't be comforted. Grade 4 decreased appetite, drowsiness and irritability events led to emergency room visit or hospitalization and were classified by investigator/medically qualified person. Any systemic event: any fever, decreased appetite, drowsiness, irritability.	Day 1 through Day 7, where Day 1 is the day of Dose 2 administration (Visit 3 of study)
Percentage of Participants With Adverse Events (AEs) From Dose 1 Through 1 Month After Dose 2	An AE was any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Results excluded local reactions and systemic events data.	From Dose 1 through 1 month after Dose 2 [up to approximately 3.7 months]
Percentage of Participants With Serious Adverse Events (SAEs) From Dose 1 Through 1 Month After Dose 2	An AE was any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. An SAE was an AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or nonpathogenic; other situations as judged by investigator.	From Dose 1 through 1 month after Dose 2 [up to approximately 3.7 months]

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Geometric Mean Concentration (GMCs) of Pneumococcal Immunoglobulin G (IgG) at 1 Month After Dose 1	GMCs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the student t distribution).	1 month after Dose 1
GMCs of Pneumococcal IgG at 1 Month After Dose 2	GMCs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the student t distribution).	1 month after Dose 2
Percentage of Participants With Predefined IgG Concentrations at 1 Month After Dose 1	Predefined IgG concentrations was >= 0.35 micrograms per milliliter (mcg/mL).	1 month after Dose 1
Percentage of Participants With Predefined IgG Concentrations at 1 Month After Dose 2	Predefined level of IgG concentrations was >= 0.35 mcg/mL.	1 month after Dose 2
Geometric Mean Fold Rise (GMFRs) of Pneumococcal IgG From Before Dose 1 to 1 Month After Dose 1	GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the student-t distribution).	From before Dose 1 to 1 month after Dose 1
GMFRs of Pneumococcal IgG From 1 Month After Dose 1 to 1 Month After Dose 2	GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the student-t distribution).	From 1 month after Dose 1 to 1 month after Dose 2
Geometric Mean Titer (GMTs) of Pneumococcal Opsonophagocytic Activity (OPA) at 1 Month After Dose 1	GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on student's t distribution).	1 month after Dose 1
GMTs of Pneumococcal OPA at 1 Month After Dose 2	GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on student's t distribution).	1 month after Dose 2
GMFRs of Pneumococcal OPA From Before Dose 1 to 1 Month After Dose 1	GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the student-t distribution).	From before Dose 1 to 1 month after Dose 1
GMFRs of Pneumococcal OPA From 1 Month After Dose 1 to 1 Month After Dose 2	GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the student-t distribution).	From 1 month after Dose 1 to 1 month after Dose 2

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): November 8, 2023
• Primary Completion (Actual): May 27, 2024
• Study Completion (Actual): May 27, 2024

Study Registration Dates

• First Submitted: October 30, 2023
• First Submitted That Met QC Criteria: October 30, 2023
• First Posted (Actual): November 3, 2023

Study Record Updates

• Last Update Posted (Actual): May 8, 2025
• Last Update Submitted That Met QC Criteria: April 21, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Pneumococcal Disease
• Other Study ID Numbers: C4801002; 2023-505154-18-00 (Registry Identifier: CTIS (EU))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No