FDA Extends Dynavax’s Hep B Vaccine Review

On August 3, 2017, Dynavax Technologies (Berkeley, CA, US), a clinical-stage immunology company, announced that FDA has requested more detailed information about the company's proposed post-marketing study for Heplisav-B (hepatitis B vaccine, recombinant [adjuvanted]), thereby extending the Prescription Drug User Fee Act (PDUFA) date, which was scheduled for August 10, 2017. FDA and Dynavax have agreed that more time is needed to finalize key details of the post-marketing study. FDA’s request is based on feedback from its vaccines and related biological products advisory committee during a meeting on July 28, 2017.

As indicated in FDA's request for additional information, and consistent with a discussion regarding myocardial infarction at the advisory committee meeting, the remaining details to address in the post-marketing study include:

• Timeline for the final protocol submission, study completion, and final report submission

• Timeliness of accruing patients into the study

• Time points for data review

• Measures to control for potential biases between study arms

• Updated statistical analysis plan.

To create sufficient time to complete this work under the existing regulatory framework, Dynavax’s response to the information request will trigger a major amendment to the biologics license application for the vaccine. This will provide FDA and Dynavax up to three months to agree on the post-marketing study prior to an updated PDUFA date (expected to be no later than November 10, 2017). This timing does not impact the company's plans to launch Heplisav-B commercially in the United States in early 2018.

"Our conversation with the [a]gency was open and productive and confirmed our mutual understanding of the [advisory committee’s] suggested requirements for the post-marketing study. We are working with our third-party providers to develop an appropriate study that addresses the advisory committee's feedback. We now have clarity on the path forward and next steps required to complete the regulatory review of Heplisav-B," said Eddie Gray, CEO of Dynavax, in a company press release. "We plan to respond to the request for additional information expeditiously. We look forward to bringing this important vaccine to market to support the elimination of hepatitis B infection as a public health problem."

Heplisav-B is an investigational adult hepatitis B vaccine that combines hepatitis B surface antigen with a proprietary toll-like receptor 9 agonist to enhance the immune response. In Phase III trials, Heplisav-B showed higher and earlier protection with fewer doses than a currently licensed hepatitis B vaccine, according to Dynavax. The company has worldwide commercial rights to Heplisav-B.

Source: Dynavax Technologies