Study of a Single Dose of a 21-valent Pneumococcal Conjugate Vaccine in Children and Adolescents With Sickle Cell Disease

NCT07247188 | Recruiting Phase 3 DMC FDA Drug

• 2 other identifiers: PSK00026U1111-1319-0153
• Study Type: interventional
• Target: 100
• Locations: 2 countries
• Sites: 7

Brief Summary

The purpose of this study is to measure whether PCV21 vaccine (investigational pneumococcal vaccine) is safe and can help the body to develop germ-fighting agents called "antibodies" (immunogenicity) compared with 20vPCV (licensed pneumococcal vaccine) when given as a single dose to children aged 2 to 17 years with sickle cell disease who had received or not a previous vaccination with pneumococcal conjugate or pneumococcal polysaccharide vaccine.

Conditions

Sickle Cell Disease

Keywords

Sickle Cell Disease; Pneumococcal Vaccine; Pneumococcal Conjugate Vaccine

Outcome Measures

Primary Outcomes (5)

• Number of participants reporting immediate adverse events (AEs)

  Unsolicited (spontaneously reported) systemic AEs after injection of a pneumococcal vaccine

  Within 30 minutes post-vaccination

• Number of participants reporting solicited injection site and solicited systemic reactions

  Up to Day 7 post-vaccination

• Number of participants reporting unsolicited (spontaneously reported) injection site reactions and unsolicited systemic AEs after injection of a pneumococcal vaccine

  Within 30 days post-vaccination

• Number of participants reporting serious adverse events (SAEs) and adverse events of special interest (AESIs)

  SAEs and AESIs are collected throughout the study period

  From day 0 to day 181

• Number of participants with serotype-specific immunoglobulin G (IgG) concentrations for all serotypes included in PCV21

  Ab (antibody) concentrations for each pneumococcal serotype measured by electro-chemiluminescence (ECL) assay

  On day 30 post-vaccination

Secondary Outcomes (3)

• Number of participants with serotype-specific IgG concentrations for all serotypes included in PCV21

  Pre-vaccination and at 30 days post-vaccination

• Number of participants with serotype specific opsonophagocytic activity (OPA) titers for all serotypes included in PCV21

  On day 30

• Number of participants with serotype specific opsonophagocytic activity (OPA) titers for all serotypes included in PCV21

  Pre-vaccination and at 30 days post-vaccination

Study Arms (2)

Investigated Vaccine: PCV21

EXPERIMENTAL

Participants will receive 1 intramuscular injection of the pneumococcal vaccine

Biological: PCV21

Comparator Vaccine: 20vPCV

ACTIVE COMPARATOR

Participants will receive 1 intramuscular injection of the pneumococcal vaccine

Biological: 20vPCV

Interventions

PCV21 BIOLOGICAL

Investigational pneumococcal conjugate vaccine

Investigated Vaccine: PCV21

20vPCV BIOLOGICAL

20-valent pneumococcal conjugate vaccine

Also known as: Prevnar 20

Comparator Vaccine: 20vPCV

Eligibility Criteria

• Age: 2 Years - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• AGE
• TYPE OF PARTICIPANT AND DISEASE CHARACTERISTICS
• Participants who have a documented diagnosis of sickle cell disease (SCD) in their medical record.
• SEX, CONTRACEPTIVE/BARRIER METHOD AND PREGNANCY TESTING REQUIREMENTS
• A participant is eligible to participate if the participant is not pregnant or breastfeeding and one of the following conditions applies:
• Is of non-childbearing potential. To be considered of non-childbearing potential, a female must be pre-menarchal or surgically sterile. OR
• Is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 4 weeks after study intervention administration. A participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 25 hours before the study intervention.
• INFORMED CONSENT
• Assent form has been signed and dated by the participant (based on local regulations), and, if applicable, informed consent form has been signed and dated by the parent(s) or another legally acceptable representative (LAR) and by an independent witness, if required by local regulations.
• Participant and parent(s)/LAR are able to attend all scheduled visits and to comply with all study procedures.

You may not qualify if:

• MEDICAL CONDITIONS
• Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy.
• History of microbiologically confirmed S. pneumoniae infection or disease.
• History of seizure or significant stable or progressive neurological disorders such as inflammatory nervous system diseases, encephalopathy, and cerebral palsy.
• Known systemic hypersensitivity to any of the study interventions components, or history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances.
• Laboratory-confirmed thrombocytopenia, or known thrombocytopenia, as reported by the parent/LAR, contraindicating intramuscular (IM) injection.
• Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion.
• Moderate or severe acute illness/infection (according to investigator judgment) or febrile illness (temperature ≥ 38.0°C \[≥ 100.4°F\]) on the day of study intervention administration. A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
• For children/adolescents (6 to 17 YoA) only
• Alcohol, prescription drug, or substance abuse that, in the opinion of the Investigator, might interfere with the study conduct or completion.
• PRIOR/CONCOMITANT THERAPY
• Receipt of at least one dose of 20vPCV.
• For children aged \< 6 years: receipt of \< 3 doses of pneumococcal conjugate vaccine or any dose of 23-valent pneumococcal polysaccharide vaccine (PPSV23).
• For children and adolescents aged ≥ 6 years: receipt of PPSV23 \< 5 years before study vaccination or last PCV dose \< 8 weeks before study vaccination.
• Receipt of any vaccine in the 4 weeks preceding the study intervention administration or planned receipt of any vaccine in the 4 weeks following the study intervention administration, except for US licensed influenza vaccination, which may be received at least 2 weeks before or 2 weeks after study vaccination. This exception includes monovalent pandemic influenza vaccines and multivalent influenza vaccines, as applicable per local recommendations.

Sponsors & Collaborators

• Sanofi: lead

Study Sites (7)

Site # 8400006

Atlanta, Georgia, 30310, United States

RECRUITING

Site # 8400002

Atlanta, Georgia, 30322, United States

RECRUITING

Site # 8400003

Omaha, Nebraska, 68114, United States

RECRUITING

Site # 8400001

New Brunswick, New Jersey, 08901, United States

RECRUITING

Site # 8400004

Houston, Texas, 77030, United States

RECRUITING

Site # 2140001

Santo Domingo, Dominican Republic

RECRUITING

Site # 2140003

Santo Domingo, Dominican Republic

RECRUITING

MeSH Terms

Conditions

Anemia, Sickle Cell

Condition Hierarchy (Ancestors)

Anemia, Hemolytic, Congenital; Anemia, Hemolytic; Anemia; Hematologic Diseases; Hemic and Lymphatic Diseases; Hemoglobinopathies; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Clinical Sciences & Operations Study Director

  Sanofi

  STUDY DIRECTOR

Central Study Contacts

Trial Transparency email recommended (Toll free number for US & Canada)

CONTACT

800-633-1610; contact-us@sanofi.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Modified double-blind: * Blinding for vaccine group assignment: participants and participant's parent(s)/legally acceptable representative(s), outcome assessors, Investigators, laboratory personnel, and Sponsor study staff * No blinding for vaccine group assignment: study staff preparing and administering the study interventions
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Control method: Active-controlled

Study Record Dates

• First Submitted: November 19, 2025
• First Posted: November 25, 2025
• Study Start: January 20, 2026
• Primary Completion (Estimated): January 7, 2027
• Study Completion (Estimated): January 7, 2027
• Last Updated: April 15, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share

Locations

US (5); DO (2)