Valneva Reports Further Positive Pivotal Phase 3 Data in Adolescents for its Single-Shot Chikungunya Vaccine

Results Intended to Support Filing for Potential Label Extension for Use in Adolescents

Saint-Herblain (France), May 13, 2024 – Valneva SE (Nasdaq: VALN; Euronext Paris: VLA), a specialty vaccine company, today reported further positive pivotal Phase 3 data in adolescents for its single-shot chikungunya virus (CHIKV) vaccine. Following the initial analysis up to Day 29 post-vaccination, the most recent analysis of study VLA1553-321 evaluated the safety and immunogenicity six months (Day 180) after vaccination with a single dose of the vaccine. The Day 180 results confirm the initial positive immunogenicity and safety data Valneva reported previously^1,2, and are intended to support filing for potential label extension for use in adolescents aged 12 to 17 years. The data are also expected to support licensure of IXCHIQ in Brazil, which would be the first potential approval for use in endemic populations.

The latest VLA1553-321 data confirmed that a single-dose vaccination with VLA1553 induced a high, sustained immune response with a seroresponse rate of 99.1% (232 out of 234 participants) at Day 180 compared to 98.8% (248 out of 251 participants) at Day 29 in an immunogenicity subset of individuals who were CHIKV negative at baseline.

Geometric mean antibody titers (GMTs) consistently surpassed the seroresponse threshold defined with the U.S. Food and Drug Administration (FDA)³ as the surrogate of protection in baseline seronegative participants who received a single dose of VLA1553.

Additionally, the Day 180 data confirmed that a single dose of the vaccine was generally safe and well tolerated in adolescents receiving VLA1553, irrespective of previous infection with the chikungunya virus. Throughout the trial, an Independent Data Safety Monitoring Board (IDSMB) consistently assessed safety data and found no safety issues. The majority of solicited adverse events observed following VLA1553 administration were mild or moderate and resolved within three days post vaccination. 

Juan Carlos Jaramillo M.D., Chief Medical Officer of Valneva, said, “We are highly encouraged by these data, as they reinforce the strong immunity and safety observed in adults and the elderly, upon which FDA approval was granted. Given the substantial risk that chikungunya presents to individuals residing in or traveling to endemic regions, it's imperative to ensure the vaccine is available to all age groups. This broader accessibility can help provide protection and mitigate the burden of this debilitating illness."