Earlier this month, the FDA backed off on a pause in shipments of the chikungunya vaccine Ixchiq to older adults. Now, the regulator has reversed course.
The FDA has suspended the approval of Valneva’s chikungunya vaccine Ixchiq due to “serious safety concerns” including at least one death that was “directly attributable to the vaccine.”
The FDA noted in an announcement Friday that Ixchiq “appears to be causing chikungunya-like illness” in patients who had been inoculated. To date, the regulator has documented more than 20 reports of serious side effects consistent with chikungunya-like illness in recipients of the vaccine. Of these, 21 resulted in hospitalization and three led to death, including one from encephalitis that has been linked to the shot, per the announcement.
According to a company release on Friday, the suspension is “effective immediately and requires Valneva to stop shipping and selling” Ixchiq in the U.S.
Valneva’s shares declined 21% to $9.10 in pre-market trading Monday, compared to $11.64 at close on Friday.
The FDA action caps a months-long rough patch for Valneva and Ixchiq. In May, the FDA and CDC recommended a temporarily halt on the use of the vaccine in people 60 years old and above amid “reports of serious adverse events, including neurologic and cardiac events.” At the time, the agencies had already flagged 17 serious complications in this age group, including two that have “resulted in death.”
Then, earlier this month, the FDA lifted the pause, but recommended stricter labelling for the vaccine in this older patient subgroup. The FDA required Valneva to change Ixchiq’s prescribing information to say that the vaccine is only indicated for those who are “at high risk” of being exposed to the chikungunya virus. The label’s original language noted that Ixchiq was approved for those at “increased risk” of infection.
Additionally, the FDA asked Valneva to include warnings that reflect these post-marketing findings for Ixchiq, including “adverse reactions that are consistent with severe complications of chikungunya, resulting in hospitalization, including encephalitis in a person who died.”
Now, the shot has been pulled from the market. The agency’s “benefit-risk analysis broadly shows the vaccine does not have benefits outweighing risks, under most plausible scenarios,” the FDA said in its Friday update. Continued inoculation of patients “would pose a danger to health.”
Ixchiq is a live attenuated virus shot that in November 2023 became the first FDA-approved chikungunya vaccine. The nod came via the regulator’s accelerated pathway, which requires Valneva to validate the shot’s clinical benefit in a confirmatory trial. In its announcement on Friday, the FDA alluded to the accelerated nature of Ixchiq’s approval, noting that “the clinical benefit of the vaccine has not yet been verified in confirmatory clinical studies.”
Despite having the product pulled, Valneva will for now maintain its full-year 2024 guidance, as per its Friday release. In its second-quarter report earlier this month, the company said it expects product sales to hit €170 million to €180 million, or around $199 million to $210 million. In the first half of the year, Ixchiq brought in €7.5 million, or nearly $8.8 million.
