Bavarian Nordic Reports Positive Phase 3 Topline Results for Chikungunya Virus Vaccine in Adults and Adolescents

• Chikungunya vaccine candidate met all the co-primary endpoints of the Phase 3 study and was shown to be highly immunogenic in the majority of subjects 22 days post a single vaccination.
• A fast and durable response was confirmed with high levels of immunity at both 2 weeks and 6 months post a single vaccination.
• Regulatory submissions planned for 2024
• Conference call Monday, August 7 at 2 pm CEST / 8 am EDT

COPENHAGEN, Denmark, August 6, 2023 – Bavarian Nordic A/S (OMX: BAVA) announced today positive topline results from a randomized, double-blind, placebo-controlled Phase 3 clinical trial (NCT05072080) of its virus-like particle (VLP)-based chikungunya virus vaccine candidate, CHIKV VLP (PXVX0317) in adults and adolescents aged 12 to 64 years of age.

A total of 3,254 participants were enrolled and randomized to receive either a single intramuscular injection of CHIKV VLP, or placebo. The results up to day 22 post vaccination showed that CHIKV VLP was highly immunogenic in healthy adolescents and adults, as demonstrated by the strong induction of chikungunya neutralizing antibodies in 98% of vaccinees in the active group. The strong neutralizing antibody titres were equal to, or exceeded the threshold agreed with authorities as a marker of seroprotection, meeting primary objectives of the study.

Importantly, CHIKV VLP induced significant neutralizing antibodies in 97% of the subjects at 2 weeks post vaccination, confirming a rapid onset of protective levels of immunity. These responses were robust and durable, as 86% of the subjects had seroprotective levels of neutralizing antibodies 6 months post vaccination.

CHIKV VLP was well-tolerated in this adolescent and adult population and adverse events were mainly mild or moderate in nature.

“We are highly encouraged by the positive topline results now demonstrated in both Phase 3 studies of our chikungunya vaccine candidate. Our focus remains to finalize the studies and prepare for regulatory submissions next year,” said Paul Chaplin, President and CEO of Bavarian Nordic. “With a fast and durable response, our vaccine has the potential to be the best in class to prevent chikungunya infections in adolescents to elderly adults. Chikungunya that can often result in a severe and incapacitating disease affects large parts of the world, and with international travel on the rise again, our CHIKV vaccine offers a significant opportunity to address this large unmet medical need.”