FDA Rejects Dynavax’s Bid to Expand Use of Hepatitis B Vaccine

FDA Exterior/iStock, Grandbrothers

Pictured: The front entrance to the FDA headquarters/iStock, Grandbrothers

Dynavax Technologies announced Tuesday that the FDA rejected the company's supplemental Biologics License Application for expanded use of its four-dose hepatitis B vaccine for adults on hemodialysis. 

The California biopharma said it received a Complete Response Letter (CRL) from the regulator for its sBLA, which included clinical immunogenicity and safety data from the Phase I HBV-24 study of a four-dose Heplisav-B regimen in 119 adults undergoing hemodialysis. According to the CRL, the “application did not provide sufficient data to support the full evaluation of effectiveness or safety.” 

“The CRL stated that the data from HBV-24 were insufficient 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,” Dynavax said in its announcement. 

The company also revealed that the total number of subjects in the single-arm study was found by the FDA to be “insufficient to evaluate safety of the four-dose regimen.” 

Dynavax said in its press release that the FDA’s rejection of its sBLA will not impact the approval decision in October 2023 from the European Commission of the four-dose regimen for hemodialysis patients, or the approved indication for Heplisav-B in the U.S., the European Union and U.K. for the prevention of infection caused by all known subtypes of hepatitis B virus in adults. 

“We are reviewing the agency’s feedback and intend to request a meeting with the FDA to evaluate options for providing additional data to support the four-dose regimen for this vulnerable patient population in the U.S.,” Dynavax CMO Rob Janssen said in a statement. 

Janssen added that the company remains “confident” in the key data collected in HBV-24 which “were verified against original source documents during the conduct of the trial.” 

This isn’t the first regulatory bump in the road for Dynavax’s hepatitis B shot. Prior to the vaccine’s approval in 2017, it was rejected twice by the FDA over unresolved safety concerns. 

Dynavax was hoping the expanded use of its hepatitis B vaccine would strengthen its market foothold. Revenues for 2023 showed the shot brought in $213 million, with Heplisav-B securing around 42% of the U.S. market. The company forecast net product revenues of between $265 million to $280 million in 2024. Dynavax did not indicate if Tuesday’s FDA rejection will affect its growth estimates. 

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at kate.goodwin@biospace.com and on LinkedIn.

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