NCT06007183

Long-term Follow-up Study to Evaluate Safety and Immunogenicity of PXVX0317 Single or Booster Vaccination

A Long-term Follow-up Study to Evaluate Safety and Immunogenicity of a Chikungunya Virus Virus-like Particle Vaccine (PXVX0317) in Healthy Adults and Adolescents After Either a Single or Booster Vaccination Dosing Regimen

• Status: Active Not Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 800 (estimated)
• Sponsor: Bavarian Nordic · Industry
• Sex: All
• Age: 12 Years
• Healthy volunteers: Accepted

Summary

The purpose of this phase 3 multicenter, randomized, double-blind, placebo-controlled rollover study is to evaluate the safety and long-term immunogenicity of CHIKV VLP vaccine in adult and adolescent participants and to evaluate CHIKV VLP booster vaccine induced serum neutralizing antibody (SNA) response at 3, 4, or 5 years post-initial CHIKV VLP vaccination.

Detailed description

Primary Objectives: * To evaluate the long-term immunogenicity of CHIKV VLP vaccine in healthy adult and adolescent participants as measured by proportion of participants maintaining an anti-CHIKV serum neutralizing antibody (SNA) titer ≥100 (seroresponse rate, also considered the presumptive seroprotection rate) at yearly intervals up to 5 years postvaccination in feeder studies EBSI-CV-317-004 (NCT05072080) and EBSI-CV-317-005 (NCT05349617). * To assess the vaccine-induced SNA titers by a booster dose of CHIKV VLP vaccine at 3, 4, or 5 years post-initial vaccination in feeder studies EBSI-CV- 317-004 and EBSI-CV-317-005. * To evaluate the safety and tolerability of CHIKV VLP vaccine in all participants. * To evaluate the safety and tolerability of a booster vaccination and compare with safety and tolerability reported post-initial vaccination of CHIKV VLP vaccine under feeder studies EBSI-CV-317-004 and EBSI-CV-317-005 in healthy adults and adolescents. Secondary Objectives: * To evaluate the long-term immunogenicity of CHIKV VLP vaccine in healthy adult and adolescent participants as measured by anti-CHIKV SNA geometric mean titers (GMTs) at yearly intervals up to 5 years post-initial vaccination in feeder studies EBSI-CV-317-004 and EBSI-CV-317-005. * To evaluate the immune response to a booster vaccination and compare this response to that reported post-initial vaccination of CHIKV VLP vaccine under feeder studies EBSI-CV-317-004 and EBSI-CV-317-005 in healthy adults and adolescents.

Conditions

• Chikungunya Virus Infection

Interventions

Type	Name	Description
BIOLOGICAL	CHIKV VLP vaccine booster	CHIKV VLP vaccine is comprised of chikungunya virus virus-like particles (CHIKV VLP) 40mg, aluminum hydroxide 2% adjuvant, and formulation buffer supplied as a single dose of 0.8 mL in a pre-filled syringe, to be administered via intramuscular (IM) injection in the deltoid muscle.
BIOLOGICAL	Placebo booster	Placebo is comprised of formulation buffer supplied as a single dose of 0.8 mL in a pre-filled syringe administered via IM injection in the deltoid muscle.

Timeline

• Start date: 2023-08-30
• Primary completion: 2028-04-01
• Completion: 2028-08-01
• First posted: 2023-08-23
• Last updated: 2025-04-03

Locations

24 sites across 1 country: United States

Regulatory

• FDA-regulated drug study