After the FDA halted its marketing approval, French firm Valneva has opted to voluntarily pull its chikungunya vaccine Ixchiq from the U.S. market.
The FDA halted Ixchiq’s approval in August upon identifying significant safety issues linked to the vaccine. At that point, the regulator stated it had documented one fatality from encephalitis “directly attributable” to the immunization, along with over 20 severe adverse incidents—including hospitalizations and deaths—that aligned with symptoms “consistent with chikungunya-like illness.”
Valneva reported that the FDA has recently initiated a clinical hold on Ixchiq’s development program to examine a new case reported outside the United States. The incident involved a younger adult recipient who received three immunizations concurrently, one of which was Ixchiq. Valneva classified the event as “plausibly related to Ixchiq vaccination” but noted that “causality has not been determined.”
Having received FDA accelerated approval in November 2023, Ixchiq was the globe’s inaugural vaccine for chikungunya. Its departure leaves Bavarian Nordic’s Vimkunya as the sole remaining chikungunya vaccine available in the United States.
To verify Ixchiq’s effectiveness and safety, Valneva had intended to commence a post-marketing phase 4 initiative, which included a randomized controlled efficacy and safety trial for adults in endemic regions, while maintaining discussions with regulators for expanded use in high-risk groups. Given the withdrawal, it now seems Valneva does not intend to reintroduce Ixchiq to the U.S. market, even after concluding the post-marketing study, as noted by Fierce Pharma.
Valneva stated it remains in communication with other health authorities in Europe, Canada, the U.K., and Brazil, where Ixchiq holds licenses. Although the vaccine’s various approvals focus on travelers, Valneva maintains that “Ixchiq’s benefit-risk profile also remains favorable for people living in the endemic and outbreak settings.”