Safety, Tolerability, and Immunogenicity of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Healthy Infants

Vaxcyte

Status and phase: Active, not recruiting; Phase 2

Conditions: Pneumococcal Vaccines

Treatments: Biological: 0.5 ml dose of 1.1 mcg VAX-24; Biological: 0.5 ml dose of PCV20; Biological: 0.5 ml dose of 2.2/4.4 mcg VAX-24; Biological: 0.5 ml dose of 2.2 mcg VAX-24

Study type: Interventional

Funder types: Industry

Identifiers

NCT05844423

VAX24-112

Details and patient eligibility

About

The objective of the study is to evaluate the safety and tolerability of 4 injections of VAX-24 (at 3 dose levels) compared to PCV15 in infants at 2, 4, 6, and 12-15 months of age, in addition to receiving routine US concomitant vaccines. Stage 1 of the study will comprise 3 dose ascending cohorts. Stage 2 of the study will enroll the remainder of the sample size.

Enrollment: 802 patients

Sex: All

Ages: 42 to 89 days old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Healthy male or female infant ≥42 days to ≤89 days (inclusive).
2. Full-term infant at least 37 weeks gestational age at birth.
3. Afebrile for ≥72 hours with a rectal temperature <38.0°C (<100.4°F) or axillary temperature <37.8°C (<100.0°F) before receipt of study vaccine.*
4. Able to attend all scheduled visits and comply with the study procedures.
5. Subject's parent/legal guardian is able to read and understands the study procedures, alternate treatments, risks and benefits, and provides written informed consent.
6. Subject's parent/legal guardian is able to fill out an ediary of solicited AE and take daily axillary temperature and measurements of local injection site reactions for the 7 days after each study vaccination.
7. Subject's parent/legal guardian has an e-mail address and access to a computer or smartphone with internet to complete the ediary.

Exclusion criteria

1. History of invasive pneumococcal disease (positive blood culture, positive cerebrospinal fluid culture, or other sterile site) or known history of other culture positive pneumococcal disease.
2. Previous receipt of a licensed or investigational vaccine (excluding 1 dose hepatitis B vaccine).
3. Known hypersensitivity to any vaccine.
4. Known or suspected impairment of immunological function (e.g., asplenia, HIV, primary immunodeficiency).
5. Use of any immunosuppressive therapy (Note: topical and inhaled/nebulized steroids are permitted).
6. History of failure to thrive.
7. Subject has a coagulation disorder contraindicating IM vaccination.
8. Subject or his/her mother have documented hepatitis B surface antigen-positive.
9. Has a known neurologic or cognitive behavioral disorder.
10. Has a known clinically significant congenital malformation or serious chronic disorder.
11. Receipt of a blood transfusion or blood products, including immunoglobulins.
12. Receipt of any investigational study product since birth, currently participating in another interventional investigational study, or having plans to receive another investigational product(s) while on study.
13. Any infant who cannot be adequately followed for safety according to the protocol plan.
14. Any other reason that in the opinion of the investigator may interfere with the evaluation required by the study.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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802 participants in 4 patient groups

VAX-24 Low

Experimental group

Description:

Participants will receive 4 doses of VAX-24 administered as an intramuscular injection at 2, 4, 6, and 12-15 months of age at one of three dose levels.

Treatment:

Biological: 0.5 ml dose of 1.1 mcg VAX-24

VAX-24 Mid

Experimental group

Description:

Participants will receive 4 doses of VAX-24 administered as an intramuscular injection at 2, 4, 6, and 12-15 months of age at one of three dose levels.

Treatment:

Biological: 0.5 ml dose of 2.2 mcg VAX-24

VAX-24 Mixed

Experimental group

Description:

Participants will receive 4 doses of VAX-24 administered as an intramuscular injection at 2, 4, 6, and 12-15 months of age at one of three dose levels.

Treatment:

Biological: 0.5 ml dose of 2.2/4.4 mcg VAX-24

PCV20

Active Comparator group

Description:

Participants will receive 4 doses of PCV20 administered as an intramuscular injection of the standard dose at 2, 4, 6, and 12-15 months of age.

Treatment:

Biological: 0.5 ml dose of PCV20