Bavarian Nordic goes 2 for 2 in pivotal chikungunya vaccine trials, teeing up filing to rival Valneva

Bavarian Nordic’s chikungunya virus vaccine candidate has racked up a second phase 3 victory. Weeks after presenting positive data in seniors, the biotech has revealed pivotal results in younger adults that position it to file for approval next year to challenge Valneva for the emerging opportunity.

Valneva is leading the race to develop a chikungunya virus vaccine. With a FDA decision date scheduled for later this month, the French biotech could soon become the sponsor of the first chikungunya vaccine approved in the U.S., snagging itself a priority review voucher in the process, but Bavarian Nordic’s data suggests Valneva will soon face a tussle for market share. 

Bavarian Nordic, which entered the race via a $380 million deal, looks well placed to challenge Valneva. In its second phase 3 trial, the Danish drugmaker saw “strong induction” of neutralizing antibodies in 98% of recipients of its vaccine 22 days after dosing. Most, 97%, of subjects had significant antibodies 14 days after vaccination

“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,” Bavarian Nordic CEO Paul Chaplin said in a statement. “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.” 

The speed of response is a potential point of differentiation. Valneva set a high bar for the response rate, reporting seroprotective chikungunya virus neutralizing antibody levels in 99% of subjects, but its phase 3 trial measured antibody levels 28 days after vaccination for the primary endpoint.

Valneva also measured antibody levels seven days after vaccination, but not 14 days after vaccination like Bavarian Nordic, making it hard to assess how quickly subjects responded. Immune responses kicked into high gear between day eight and day 29, over which time the mean fold increase in antibody titers in people aged 18 to 64 years rose from 4.38 to 460.27. Bavarian Nordic can show an earlier response.

Durability is another potential battleground. Both companies saw antibody levels fall after the primary endpoint analyses but emerged with data that their vaccines provide protection for at least six months. In the Bavarian Nordic clinical trial, 86% of subjects had seroprotective levels of neutralizing antibodies at the six-month analysis.

Bavarian Nordic plans to file for approval in the U.S. and European Union next year, with a view to bringing the vaccine to market in 2025. The timeline suggests Valneva will have a head start in the U.S. of over a year.