Dynavax’s hepatitis B vaccine was rejected for a label expansion in the US after patient data was destroyed by a third-party clinical trial site operator, the company announced Tuesday.
The complete response letter cited the destruction of “data source documents by a third-party clinical trial site operator for approximately half of the subjects enrolled in the trial.” It also said that 119 hemodialysis patients in the single-arm HBV-24 study was not enough to determine safety, according to Dynavax.
Heplisav-B was first approved as a two-dose regimen for adults in 2017, following two regulatory stumbles over safety concerns. Dynavax filed for approval of a four-dose regimen for patients on hemodialysis in April 2023, which can be a risk factor for hepatitis B. The European Commission approved the vaccine for that indication in October.
But in the US, regulators said Heplisav-B’s application “did not provide sufficient data to support the full evaluation of effectiveness or safety,” according to Dynavax.
“We are currently reviewing the agency’s feedback and will work with the FDA to evaluate options for providing additional data and determine associated timelines,” a Dynavax spokesperson told Endpoints News on Tuesday.
Dynavax did not address questions about the trial site operator or the destruction of data in its response.
Executives recently said they expect a record sales year for Heplisav-B, noting in a first-quarter earnings report that more than 130 million people in the US are eligible for the hepatitis B vaccine, a majority of whom are unvaccinated.