A Study to Learn About the Safety and Immune Activity of RSVpreF in Children 2 to <18 Years of Age (PICASSO)

A PHASE 1, OPEN-LABEL, AGE-DESCENDING, DOSE-FINDING STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS PREFUSION F SUBUNIT VACCINE (RSVpreF) IN CHILDREN 2 TO <18 YEARS OF AGE

The purpose of this study is to learn about the safety and immune activity of the vaccine (called RSVpreF) in children 2 to <18 years of age.

This study will identify the dose level to be used in Phase 2/3 trials in this age cohort. All participants will receive one injection of RSVpreF. This study has four study visits, two in-clinic and two telehealth visits. Blood samples will be collected for testing. This study is about 6 months long for each participant and will be conducted in the United States.

Study Overview

• Status: Completed
• Conditions: RESPIRATORY SYNCYTIAL VIRUS (RSV)
• Intervention / Treatment: Biological: RSVpreF 120 µg; Biological: RSVpreF 60 µg

• Study Type: Interventional
• Enrollment (Actual): 128
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35233
      • University of Alabama at Birmingham - School of Medicine
  • California
    • Palo Alto, California, United States, 94304
      • Stanford University Medical Center
    • Rolling Hills Estates, California, United States, 90274
      • Peninsula Research Associates
  • Florida
    • Miami, Florida, United States, 33144
      • Bio-Medical Research LLC
  • Iowa
    • Sioux City, Iowa, United States, 51106
      • Velocity Clinical Research, Sioux City
  • Louisiana
    • Metairie, Louisiana, United States, 70006
      • Velocity Clinical Research, New Orleans
  • Nebraska
    • Omaha, Nebraska, United States, 68134
      • Velocity Clinical Research, Omaha
  • New York
    • Rochester, New York, United States, 14609
      • Rochester Clinical Research, LLC
  • North Carolina
    • Durham, North Carolina, United States, 27703
      • Duke Vaccine and Trials Unit
  • Ohio
    • Cincinnati, Ohio, United States, 45229
      • Cincinnati Children's Hospital Medical Center
    • South Euclid, Ohio, United States, 44121
      • Senders Pediatrics
  • Rhode Island
    • East Greenwich, Rhode Island, United States, 02818
      • Velocity Clinical Research, Providence
  • Texas
    • Austin, Texas, United States, 78759
      • Velocity Clinical Research, Austin
    • Austin, Texas, United States, 78726
      • Innovo Research - Austin Regional Clinic
  • Utah
    • West Jordan, Utah, United States, 84088
      • Velocity Clinical Research, Salt Lake City
  • Washington
    • Seattle, Washington, United States, 98105
      • Seattle Children's Hospital
    • Seattle, Washington, United States, 98101
      • Seattle Children's - Building Cure

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Participants 2 to <18 years of age at enrollment

2. Participants 2 to <18 years of age should either be healthy or be considered by the investigator to be at high risk of RSV disease based on the presence of 1 of the following chronic medical conditions:

   • Cystic fibrosis
   • Medically treated asthma
   • Other chronic respiratory diseases and malformations of the lung
   • Down syndrome
   • Neuromuscular disease
   • Cerebral palsy
   • Hemodynamically significant or symptomatic congenital heart disease
3. All participants 2 to <5 years of age must be seropositive for RSV as confirmed by serology.
4. Participants' parent(s)/legal guardian(s) and participants, as age appropriate, who are willing and able to comply with all scheduled visits, investigational plan, laboratory tests, and other study procedures, including collection of nasal swabs by participants' parent(s)/legal guardian(s) and by study staff when indicated.
5. The participant's parent(s)/legal guardian is capable of giving signed informed consent as described in the protocol. Depending on the age of the participant and according to local requirements, participants will also be asked to provide assent as appropriate (verbal or written).

Exclusion Criteria:

1. Immunocompromised individuals associated with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
2. Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention, including but not limited to systemic lupus erythematosus. Note: Stable type 1 diabetes and hypothyroidism are permitted.
3. Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
4. History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
5. Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection.
6. Individuals with a history of epilepsy or other seizure disorders, or a history of seizures and/or other neurological complications following vaccination.
7. Previous vaccination with any licensed or investigational RSV vaccine or planned receipt during study participation. Children who may have been exposed to investigational RSV vaccines through maternal immunization will be permitted.
8. Receipt of investigational or approved monoclonal antibodies against RSV within 6 months before study intervention administration, or planned receipt throughout the study.
9. Receipt of blood/plasma products or immunoglobulins within 28 days before study intervention administration, or planned receipt throughout the study.

10. Receipt of chronic systemic treatment with known immunosuppressant medications (including cytotoxic agents or systemic corticosteroids), or radiotherapy, within 60 days before study intervention administration, or planned receipt throughout the study.

    Note: Systemic corticosteroids are defined as those administered for ≥14 days at a dose of ≥20 mg/day of prednisone or equivalent (eg, for cancer or an autoimmune disease). Inhaled/nebulized, intra-articular, intrabursal, or topical (skin, eyes, or ears) corticosteroids are permitted.

11. Participation in other studies involving study intervention within 28 days prior to study entry and/or for the duration of study participation.
12. Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: standard dose in 5 to <18 years olds, healthy; standard dose (120 µg)	Biological: RSVpreF 120 µg; RSVpreF standard dose level
Experimental: standard dose in 5 to < 18 years olds, with chronic high risk conditions; standard dose (120 µg)	Biological: RSVpreF 120 µg; RSVpreF standard dose level
Experimental: standard dose in 2 to < 5 years olds; standard dose (120 µg)	Biological: RSVpreF 120 µg; RSVpreF standard dose level
Experimental: low dose in 5 to <18 years olds, healthy; low dose (60 µg)	Biological: RSVpreF 60 µg; RSVpreF low dose level
Experimental: low dose in 5 to <18 years olds, with chronic high risk conditions; low dose (60 µg)	Biological: RSVpreF 60 µg; RSVpreF low dose level
Experimental: low dose in 2 to < 5 years olds; low dose (60 µg)	Biological: RSVpreF 60 µg; RSVpreF low dose level

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Local reactions were collected in the electronic diary (e-diary) from Day 1 through Day 7 after vaccination. Local reactions included pain at injection site, redness, and swelling. For participants greater than or equal to (>=) 2 years to <12 years of age, redness and swelling were graded as mild: 0.5 to 2.0 centimeter (cm), moderate: >2.0 to 7.0 cm, and severe: > 7 cm; for participants >=12 years of age, mild: > 2.0 to 5.0 cm, moderate: >5.0 to 10.0 cm, and severe: >10 cm. Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), and severe (prevented daily activity).	Day 1 through Day 7 after Vaccination
Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Systemic events included fever, fatigue, headache, vomiting, diarrhea, muscle pain and joint pain and were recorded by participants using e-diary. Fever: oral temperature >= 38.0 degree Celsius (deg C) and categorized as >=38.0 to 38.4 deg C (mild), >38.4 to 38.9 deg C (moderate), and >38.9 to 40.0 deg C (severe). Fatigue, headache, muscle pain and joint pain were graded as mild (did not interfere with activity), moderate (some interference with activity), and severe (prevented daily routine activity). Vomiting was graded mild: 1-2 times in 24 hours (h), moderate: >2 times in 24h, and severe: required intravenous hydration. Diarrhea was graded mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h and severe: 6 or more loose stools in 24h.	Day 1 through Day 7 after Vaccination
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Vaccination	AE was defined as any untoward medical occurrence in clinical study participant, temporally associated with use of study intervention, whether or not considered related to study intervention. AEs included serious and all non-serious AE. SAEs were defined as AE that, at any dose: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent disability/incapacity; was congenital anomaly or birth defect; was suspected transmission via Pfizer product of infectious agent, pathogenic or nonpathogenic or was considered to be an important medical event. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were included.	Within 1 month post Vaccination
Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study	An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. SAEs were defined as an AE that, at any dose: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent disability or incapacity; was a congenital anomaly or birth defect; was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or nonpathogenic or that was considered to be an important medical event.	Within 6 months post Vaccination
Percentage of Participants Reporting Newly Diagnosed Chronic Medical Condition (NDCMCs) Throughout the Study	An NDCMC was defined as a disease or medical condition, which was not previously identified, that was expected to be persistent or otherwise long-lasting in its effects.	Within 6 months post Vaccination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Geometric Mean Titer of the Neutralizing Titers for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	Geometric mean titer (GMT) of neutralizing titers (NTs) of respiratory syncytial virus subgroup A and respiratory syncytial virus subgroup B (RSV A and RSV B) before vaccination and 1 month after vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5*LLOQ. GMTs and corresponding 2-sided CIs were calculated by exponentiating mean logarithm of titers and corresponding CIs (based on Student's t distribution).	Before vaccination and 1 month after vaccination
Geometric Mean Fold Rise (GMFR) of the NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination	GMFR of neutralizing titers of RSV A and RSV B from before vaccination to 1 month after vaccination were reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises and the corresponding CIs (based on the Student's t distribution).	From before vaccination to 1 month after vaccination
Median Frequencies of RSV F Antigen-Specific Cluster of Differentiation 4 (CD4+) Thymus-Derived Lymphocytes (T) Cells Expressing Interferon (IFN) Gamma and Interleukin-4 (IL-4) Before Vaccination and 1 Month After Vaccination	Median frequencies of RSV F antigen-specific CD4+ T cells expressing IFN gamma and IL-4 before vaccination and 1 month after vaccination were reported in this outcome measure. RSV F enzyme-linked immune absorbent spot assay (ELISpot) limit of detection (LOD) values were IFN gamma = 20 spot forming cell (SFC) per million peripheral blood mononuclear cell (PBMCs) and IL-4 = 4 SFC/million PBMCs. Assay results below LOD=0.5*LOD for analysis. Frequencies were defined as the count of the RSV F antigen-specific CD4+ T cells and median frequencies were defined as the median of the counts.	Before vaccination and 1 Month after vaccination

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): June 22, 2023
• Primary Completion (Actual): February 29, 2024
• Study Completion (Actual): February 29, 2024

Study Registration Dates

• First Submitted: June 2, 2023
• First Submitted That Met QC Criteria: June 2, 2023
• First Posted (Actual): June 12, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 12, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: Pediatric; RSV; Respiratory infection; RESPIRATORY SYNCYTIAL VIRUS; Respiratory illness; RSV vaccine
• Other Study ID Numbers: C3671016; 2024-000422-17 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• 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: Yes
• Studies a U.S. FDA-regulated device product: No