Enrolment concluded for Valneva’s chikungunya vaccine

Phase 3 trial of single-shot chikungunya vaccine candidate unfolds among an adolescent cohort

Valneva – a company specialising in vaccines – has completed enrolment for a phase 3 trial of its single-shot chikungunya vaccine candidate, VLA1553. The group is comprised of adolescents and initial results of the study are expected halfway through this year.

Conducted in partnership with Instituto Butantan, VLA1553-321 is a multi-centre, double-blinded, randomised and placebo-controlled phase 3 trial. In total, 754 adolescents aged 12 to 17 years were vaccinated following randomisation at a 2:1 ratio to receive either VLA1553 or the placebo.

The central target of the trial is to evaluate immunogenicity and safety 28 days after a single vaccination with VLA1553. Participants will then be evaluated for the primary endpoint and monitored for up to 12 months.

The company completed submission of the Biologics License Application (BLA) to the US Food and Drug Administration for approval of VLA1553 in individuals of 18 years and above in December 2022. If approved it could become the first chikungunya vaccine to be marketed in the US.

Valneva reported final pivotal phase 3 data for VLA1553 in March last year and final results in May. Furthermore, the company also recently reported positive antibody persistence data with a 99% seroresponse rate 12 months after the single-dose vaccination.

The research is funded by the Coalition for Epidemic Preparedness Innovations (CEPI) and aims to support the label extension in this age group following the initial regulatory approval.

Ultimately, the adolescent trial is expected to yield licences for the vaccine in Europe and Brazil, which would be the first potential approval for use in endemic populations.

Dr Esper Georges Kallas, president at Instituto Butantan, reflected: “The achievement of this goal is a major milestone to expand the vaccine indication in adolescents. Based on a single-dose schedule, the VLA1553 chikungunya vaccine could become a key tool to prevent the chikungunya disease in endemics areas and fight the disease-induced public health burden.”

Juan Carlos Jaramillo, chief medical officer at Valneva, concluded: “Recruitment completion in this study is an important milestone for the overall programme. We reported compelling pivotal phase 3 results in adults and in the elderly, and we are now looking forward to obtaining results in adolescents later this year.”