Group B Streptococcus capsular polysaccharides (serotypes Ia, Ib, II, III, IV, V) conjugated to CRM197 for Group B streptococcus disease

Inclusion criteria

• {"criterion_text":"- Inclusion Criteria – Maternal Participants - Healthy pregnant women ≤49 years of age who are between 24 0/7 and 36 0/7 weeks of gestation on the day of planned vaccination, with an uncomplicated, singleton pregnancy, and who have no known increased risk of pregnancy complications"}
• {"criterion_text":"- Inclusion Criteria – Maternal Participants - Had a fetal anomaly ultrasound examination performed at ≥18 weeks of gestation with no significant fetal abnormalities observed"}
• {"criterion_text":"- Inclusion Criteria – Maternal Participants - Documented negative human immunodeficiency virus (HIV) antibody test, syphilis test, and hepatitis B virus (HBV) surface antigen test during this pregnancy and prior to randomization"}

Exclusion criteria

• {"criterion_text":"- Exclusion Criteria – Maternal Participants - Prepregnancy body mass index (BMI) of >40 kg/m2. If a prepregnancy BMI is not available, the BMI at the time of the first obstetric visit during the current pregnancy must be used"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - Current pregnancy complications or abnormalities that may increase the risk associated with the participation in and completion of the study"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - Prior pregnancy complications or abnormalities that, based on the investigator’s judgment, may increase the risk associated with the participation in and completion of the study"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - History of microbiologically proven invasive disease caused by GBS in the current pregnancy (eg, isolation of GBS from a sterile site: blood, cerebrospinal fluid [CSF], or synovial fluid). This does not include asymptomatic bacteriuria or urinary tract infection (UTI) unless associated with a positive blood culture"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - A known or suspected infection during the current pregnancy that may increase the risk of complications in pregnancy (eg, active tuberculosis, syphilis, primary genital herpes simplex, malaria)"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - Congenital or acquired immunodeficiency disorder, rheumatologic disorder, or other illness requiring chronic treatment with known immunosuppressant medications, including monoclonal antibodies, within the year prior to enrollment"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - Receiving treatment with known systemic immunosuppressive therapy, including cytotoxic agents for cancer or an autoimmune disease, or radiotherapy, within 60 days before enrollment or planned receipt throughout the course of the study"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - Receipt or planned receipt of blood/plasma products or immunoglobulin, from 60 days before study intervention administration, or planned receipt through delivery, with 1 exception: Rho(D) immune globulin (eg, RhoGAM), which can be given at any time"}
• {"criterion_text":"- Exclusion Criteria – Maternal Participants - Receipt of monoclonal antibodies within the year prior to enrollment or the use of systemic corticosteroids (≥20 mg/day of prednisone or equivalent) for ≥14 days within 28 days prior to study vaccination and/or during study participation"}

Primary endpoints

• {"endpoint_text":"- Prespecified local reactions (redness, swelling, and pain at the injection site).","definition_or_measurement_approach":"As stated: local reactions defined as redness, swelling, and pain at the injection site."}
• {"endpoint_text":"- Prespecified systemic events (fever, nausea, vomiting, diarrhea, headache, fatigue, muscle pain, and joint pain).","definition_or_measurement_approach":"As stated: systemic events listed (fever, nausea, vomiting, diarrhea, headache, fatigue, muscle pain, joint pain)."}
• {"endpoint_text":"- Adverse events (AEs).","definition_or_measurement_approach":"As stated: adverse events (AEs) monitored and recorded."}
• {"endpoint_text":"- Serious adverse events (SAEs).","definition_or_measurement_approach":"As stated: serious adverse events (SAEs) monitored and recorded."}
• {"endpoint_text":"- Medically attended adverse events (MAAEs).","definition_or_measurement_approach":"As stated: medically attended adverse events (MAAEs) monitored and recorded."}
• {"endpoint_text":"- GBS serotype specific anti-CPS IgG antibody concentrations measured at birth in infant participants","definition_or_measurement_approach":"Measurement: serotype-specific anti-CPS IgG antibody concentrations measured at birth in infant participants (as specified)."}

Secondary endpoints

• {"endpoint_text":"- GBS serotype-specific anti-CPS IgG antibody concentrations in infant participants","definition_or_measurement_approach":"Measurement: serotype-specific anti-CPS IgG antibody concentrations in infant participants."}
• {"endpoint_text":"- GBS serotype-specific OPA antibody titers in infant participants","definition_or_measurement_approach":"Measurement: serotype-specific opsonophagocytic activity (OPA) antibody titers in infant participants."}
• {"endpoint_text":"- GBS serotype-specific anti-CPS IgG antibody concentrations measured at birth in infant participants","definition_or_measurement_approach":"Measurement: serotype-specific anti-CPS IgG antibody concentrations measured at birth in infant participants."}
• {"endpoint_text":"- GBS serotype-specific anti-CPS IgG antibody concentrations in maternal participants","definition_or_measurement_approach":"Measurement: serotype-specific anti-CPS IgG antibody concentrations in maternal participants."}
• {"endpoint_text":"- Serum IgG concentration to diphtheria toxoid in a subset of infant participants. Serum IgG concentration to PCV serotypes in a subset of infant participants","definition_or_measurement_approach":"Measurement: serum IgG concentrations to diphtheria toxoid and PCV serotypes in specified subset of infant participants."}

Methods

• Recruitment materials and arrangements documented: Study Poster (documents: K3_3_Recruitment Material_Study Poster available for ES and NL), Study Invitation Letter (document: K2_6a_Recruitment Material_Study Invitation Letter_C1091009_NL_NL_Public), FAQ Guide (K3_1_Recruitment Material_FAQ Guide_C1091009_ES_ES_Public), Study Brochure (K3_2_Recruitment Material_Study Brochure_C1091009_ES_ES_Public), Retention Items (K3_4_Recruitment Material_Retention Items available for ES and FI). Associated recruitment arrangement documents are provided per country (Spain: associatedEntityId 274531; Netherlands: associatedEntityId 278551; Finland: associatedEntityId 278272).
• Site-level recruitment material descriptions (K2_1a, K2_2 and K2_2_Recruitment-Material Description files) are present for Finland and Netherlands (site-specific recruitment material descriptions included).

Finland

Earliest CTIS Part Ii Submission Date

20-10-2025

Latest Decision Or Authorization Date

18-02-2026

Processing Time Days

122

Number Of Sites

6

Number Of Participants

320

Netherlands

Earliest CTIS Part Ii Submission Date

22-10-2025

Latest Decision Or Authorization Date

17-02-2026

Processing Time Days

118

Number Of Sites

7

Number Of Participants

196

Spain

Earliest CTIS Part Ii Submission Date

07-11-2025

Latest Decision Or Authorization Date

09-02-2026

Processing Time Days

94

Number Of Sites

14

Number Of Participants

248

Primary sponsor

Full Name

Pfizer Inc.

Organisation Type

Pharmaceutical company

Country Of Registered Address

United States

Contract research organisations

Name

Marken

Responsibilities

Courier/Logistics services

Name

Fisher Clinical Services Inc.

Responsibilities

Clinical supplies and equipment provision

Name

Signant Health

Responsibilities

Electronic COA (eCOA) Support Services

Third parties

• {"country":"United States","full_name":"Marken","duties_or_roles":"Courier/Logistics services","organisation_type":"Industry"}
• {"country":"United States","full_name":"Fisher Clinical Services Inc.","duties_or_roles":"Clinical supplies and equipment provision","organisation_type":"Pharmaceutical company"}
• {"country":"United Kingdom","full_name":"Signant Health","duties_or_roles":"Electronic COA (eCOA) Support Services","organisation_type":"Industry"}