FDA rejects label expansion for Dynavax’s hepatitis B vaccine

The US Food and Drug Administration (FDA) has declined to approve a supplemental biologics licence application (sBLA) for Dynavax Technologies’ recombinant hepatitis B vaccine, Heplisav-B.

The agency cited insufficient efficacy and safety data due to the “destruction of data source documents by a third-party clinical trial site operator for approximately half of the subjects enrolled in the trial”. The company did not disclose additional details regarding the destruction of trial documents.

The complete response letter (CRL) issued by the US FDA also went on to state that the “total number of subjects in the single-arm HBV-24 study was deemed to be insufficient to evaluate the safety of the four-dose regimen”.

The sBLA was based on clinical immunogenicity and safety data from the open-label, single-arm Phase I trial (NCT03934736). The study enrolled 119 participants with end-stage renal disease who were undergoing haemodialysis. The sBLA also included data from five other clinical trials for the Heplisav-B vaccine in patients with either chronic kidney disease or undergoing haemodialysis.

Dynavax is no stranger to receiving FDA rejections. The agency rejected Heplisav-B twice due to safety concerns – in 2013 and 2016 – before granting approval for preventing hepatitis B infection in adults in 2017.

The company’s chief medical officer Rob Janssen said: “We remain confident in the data generated to support HEPLISAV-B vaccination for adult haemodialysis patients. All key data collected in HBV-24 were verified against original source documents during the conduct of the trial.”