Clinical trial NCT07003984: A Phase 3 Trial of the CHIKV VLP Vaccine in Children
Official title: A Phase 3 Global, Randomized, Double-Blind, Placebo-Controlled, Safety and Immunogenicity Study of CHIKV VLP Vaccine in Children 2 to <12 Years of Age
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: PHASE3
Conditions: Chikungunya Virus
Keywords: Chikungunya
PXVX0317
CHIKV VLP
vaccine
immunogenicity
VIMKUNYA
children
Lead sponsor: Bavarian Nordic
Sponsor class: INDUSTRY
First posted: 2025-06-04
Enrollment: 720
Sex: ALL
Minimum age (years): 2
Maximum age (years): 11
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants will be stratified by site and age subgroup, 6 to \<12 years of age (Cohort 1) and 2 to \<6 years of age (Cohort 2), and randomized in a 4:1 ratio to receive either a single intramuscular (IM) dose of 40 µg CHIKV VLP vaccine or placebo at Day 1. Using the same strata, participants will be randomized in a 1:1 ratio to attend Visit 2 at either Day 15 or Day 22.
Primary purpose: PREVENTION

Brief summary: The goal of this multi-center, randomized, double-blind, placebo-controlled study is to evaluate the safety and immunogenicity of CHIKV VLP Vaccine in children 2 to \<12 years of age.


Eligibility criteria: Inclusion Criteria:

1. Males or females between 2 and \<12 years of age at Day 1 (day of vaccination).
2. In general good health, in the opinion of the investigator, based on medical history and physical examination.
3. Able and willing to provide informed assent for study participation and primary caregiver is able and willing to provide informed consent for study participation, in accordance with the Institutional Review Board (IRB)/Independent Ethics Committee (IEC) determination and applicable federal and local regulations and guidelines.
4. Able and willing to complete all scheduled visits and comply with all study procedures.

Exclusion Criteria:

1. Participation or planned participation in an investigational clinical study (eg, vaccine, drug) within 30 days before Day 1 and for the duration of the study. Note: Participation in an observational study or follow-up phase of a study may be allowed; these instances should be discussed with the sponsor's medical monitor and written agreement obtained prior to enrollment.
2. Current acute illness, with or without fever.
3. Current or recent CHIKV infection indicated by positive immunoglobulin M (IgM) and negative immunoglobulin G (IgG) rapid diagnostic test (RDT) results at screening in the Philippines only; participants in the US will not be tested using the RDT.
4. History of any known or suspected allergy or history of anaphylaxis to any component of the investigational product.
5. History of any known congenital or acquired immunodeficiency or immunosuppressive condition that could impact response to vaccination.
6. Prior receipt or anticipated use of systemic immunomodulatory or immunosuppressive medications from 180 days prior to screening through Day 22. Note: Systemic corticosteroid use at a dose or equivalent dose of 20 mg or greater (≥0.5 mg/kg for children \<40 kg) of prednisone for 14 consecutive days or more within 90 days of screening through Day 22 is exclusionary. The use of inhaled, intranasal, topical, or ocular steroids is allowed.
7. Receipt or anticipated receipt of immunoglobulin from 180 days prior to screening through the duration of the study.
8. Any administration or planned administration of:

   * A licensed live attenuated vaccine within 28 days before administration of investigational product and until Visit 2 (Day 15 or 22, as applicable) has occurred.
   * Other licensed (not live) vaccine within 14 days before administration of investigational product and until Visit 2 (Day 15 or 22, as applicable) has occurred.
   * Another licensed or investigational CHIKV vaccine.
9. Known infection with human immunodeficiency virus, hepatitis C virus (HCV), or hepatitis B virus. Note: Positive anti-HCV antibodies and negative HCV polymerase chain reaction would NOT be exclusionary. Polymerase chain reaction testing will not be performed as part of this protocol.
10. Bleeding disorder or receipt of anticoagulants in the 21 days before Day 1, contraindicating intramuscular vaccination, as judged by the investigator.
11. Receipt or anticipated receipt of blood products from 90 days before Day 1 through the duration of the study.
12. Onset of menarche prior to study vaccination.
13. Planned medical or surgical procedure that could adversely impact the participant's participation or the conduct of the study.
14. Identified as an immediate family member of the investigator or employee with direct involvement in the study. Bavarian Nordic staff members and their families, contractors, agents, business partners, and anyone with a financial interest in the outcome of the study.
15. Any other medical condition, including severe malnutrition, that, in the opinion of the investigator, could adversely impact the participant's participation or conduct of the study.

Primary outcomes:
measure: Primary Immunogenicity Endpoint
timeFrame: Study Day 22, 21 days after vaccination with CHIKV VLP vaccine or placebo.
measure: Safety Endpoint 1
timeFrame: From vaccination on study Day 1 through Day 8, 7 days after vaccination with CHIKV VLP vaccine or placebo.
measure: Safety Endpoint 2
timeFrame: From vaccination on Day 1 through Day 29, 28 days after vaccination with CHIKV VLP vaccine or placebo.
measure: Safety Endpoint 3
timeFrame: From vaccination through the end of the trial, planned to be Day 732 for study completers.
Secondary outcomes:
measure: Key Secondary Immunogenicity Endpoint 1
timeFrame: Study Day 15, 14 days after vaccination with CHIKV VLP vaccine or placebo.
measure: Key Secondary Immunogenicity Endpoint 2
timeFrame: Study Day 22, 21 days after vaccination with CHIKV VLP vaccine or placebo.
measure: Secondary Immunogenicity Endpoint 1
timeFrame: Study Day 15, 14 days after vaccination with CHIKV VLP vaccine or placebo.
measure: Secondary Immunogenicity Endpoint 2
timeFrame: Study Day 183 and Day 366, 182 and 365 days after vaccination with CHIKV VLP vaccine or placebo, respectively.
measure: Secondary Immunogenicity Endpoint 3
timeFrame: Day 15, Day 22, Day 183, and Day 366, 14, 21, 182, and 365 days after vaccination with CHIKV VLP vaccine or placebo, respectively.
measure: Secondary Immunogenicity Endpoint 4
timeFrame: Day 15, Day 22, Day 183, Day 366, and Day 732, 14, 21, 182, 365, and 731 days after vaccination, respectively.
measure: Secondary Immunogenicity Endpoint 5a
timeFrame: Day 15, Day 22, Day 183, Day 366, and Day 732, 14, 21, 182, 365, and 731 days after vaccination, respectively.
measure: Secondary Immunogenicity Endpoint 5b
timeFrame: Day 15, Day 22, Day 183, Day 366, and Day 732, 14, 21, 182, 365, and 731 days after vaccination, respectively.
measure: Secondary Immunogenicity Endpoint 6
timeFrame: Study Day 732, 731 days after vaccination with CHIKV VLP vaccine.
measure: Secondary Immunogenicity Endpoint 7
timeFrame: Study Day 22, 21 days after vaccination with CHIKV VLP vaccine or placebo.
Other outcomes:
Locations:
city: Omaha
country: United States
facility: Velocity Clinical Research-Omaha
state: Nebraska
city: West Jordan
country: United States
facility: Velocity Clinical Research - Salt Lake City
state: Utah
Study officials:
affiliation: Bavarian Nordic A/S
name: Patrick Ajiboye, MD
role: STUDY_DIRECTOR
References:
citation: Bennett SR, McCarty JM, Ramanathan R, Mendy J, Richardson JS, Smith J, Alexander J, Ledgerwood JE, de Lame PA, Royalty Tredo S, Warfield KL, Bedell L. Safety and immunogenicity of PXVX0317, an aluminium hydroxide-adjuvanted chikungunya virus-like particle vaccine: a randomised, double-blind, parallel-group, phase 2 trial. Lancet Infect Dis. 2022 Sep;22(9):1343-1355. doi: 10.1016/S1473-3099(22)00226-2. Epub 2022 Jun 13.
citation: McCarty JM, Bedell L, Mendy J, Coates EE, Chen GL, Ledgerwood JE, Tredo SR, Warfield KL, Richardson JS. Chikungunya virus virus-like particle vaccine is well tolerated and immunogenic in chikungunya seropositive individuals. Vaccine. 2023 Oct 6;41(42):6146-6149. doi: 10.1016/j.vaccine.2023.08.086. Epub 2023 Sep 9.
citation: Richardson JS, Anderson DM, Mendy J, Tindale LC, Muhammad S, Loreth T, Tredo SR, Warfield KL, Ramanathan R, Caso JT, Jenkins VA, Ajiboye P, Bedell L; EBSI-CV-317-004 Study Group. Chikungunya virus virus-like particle vaccine safety and immunogenicity in adolescents and adults in the USA: a phase 3, randomised, double-blind, placebo-controlled trial. Lancet. 2025 Apr 19;405(10487):1343-1352. doi: 10.1016/S0140-6736(25)00345-9. Epub 2025 Mar 27.