NCT04546724

Pivotal Study to Evaluate Safety and Immunogenicity of a Live-Attenuated Chikungunya Virus Vaccine Candidate in Adults

A Multicenter, Randomized, Placebo-Controlled, Double-Blinded Pivotal Study To Evaluate Safety And Immunogenicity Of A Live-Attenuated Chikungunya Virus Vaccine Candidate In Adults Aged 18 Years And Above

• Status: Completed
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 4,128 (actual)
• Sponsor: Valneva Austria GmbH · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

This was a prospective, randomized, double-blinded, multicenter, pivotal clinical study evaluating the final dose of VLA1553 (1 x10E4 TCID50 per dose) in comparison to a placebo control. The final dose of VLA1553 or control was administered as single immunization on Day 1. Overall, 4.128 male and female subjects aged 18 years and above were randomized into the study.

Detailed description

This was a prospective, double-blinded, multicenter, randomized, pivotal Phase 3 study and 4.128 participants aged 18 years or above were randomized in a 3:1 ratio to the live-attenuated CHIKV vaccine candidate (VLA1553) or placebo. The final dose of lyophilized VLA1553 or placebo was administered as a single intramuscular immunization. Subjects in this study were stratified into two age strata of 18 to 64 years and 65 years of age or above. The primary objective of the study was to evaluate the immunogenicity and safety of the final dose of VLA1553 28 days following the single immunization. Immunogenicity evaluations in the immunogenicity subset included the proportion of subjects with seroprotective neutralizing CHIKV antibody titers above a surrogate threshold indicative of protection. The surrogate of protection reasonably likely to predict clinical benefit has been established in non-human primate passive transfer studies using human sera from the Phase 1 study and was supported by sero-epidemiological studies. Safety data collection and immunogenicity were assessed until Month 6. The first enrolled and randomized 501 subjects comprised the immunogenicity subset.

Conditions

• Chikungunya Virus Infection

Interventions

Type	Name	Description
BIOLOGICAL	VLA1553	Single intramuscular vaccination on Day 1 with VLA1553, a lyophilized live-attenuated Chikungunya vaccine candidate; 1x10E4 TCID50 per dose
BIOLOGICAL	Placebo	Single intramuscular vaccination on Day 1 with Phosphate-Buffered Saline (PBS) as placebo

Timeline

• Start date: 2020-09-17
• Primary completion: 2021-05-19
• Completion: 2021-10-15
• First posted: 2020-09-14
• Last updated: 2023-06-28
• Results posted: 2022-07-25

Locations

44 sites across 1 country: United States

Regulatory

• FDA-regulated drug study