Dynavax Provides U.S. Regulatory Update on HEPLISAV-B(TM) Following FDA Advisory Committee Meeting

BERKELEY, CA--(Marketwired - August 03, 2017) - Dynavax Technologies Corporation (NASDAQ: DVAX) today announced that the U.S. Food and Drug Administration (FDA) has requested more detailed information about the company's proposed post-marketing study for HEPLISAV-B™ [Hepatitis B Vaccine, Recombinant (Adjuvanted)] based on feedback received from the FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) during a meeting on July 28, 2017. The Advisory Committee voted 12 to 1 (with 3 abstentions) that the safety data for HEPLISAV-B support licensure for active immunization against hepatitis B infection in adults 18 years of age and older while also commenting on the design of Dynavax's proposed post-marketing study for HEPLISAV-B. Dynavax and the FDA have discussed the outcome of the VRBPAC meeting and have agreed that due to the feedback provided and the proximity to the scheduled Prescription Drug User Fee Act (PDUFA) date of August 10, 2017, more time is required to finalize key details of the post-marketing study.

"Our conversation with the Agency was open and productive and confirmed our mutual understanding of the VRBPAC'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, chief executive officer of Dynavax. "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."

As indicated in the FDA's request for additional information, and consistent with the discussion regarding myocardial infarction at the VRBPAC 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

In order to create sufficient time to complete this work under the existing regulatory framework, the response to the information request will trigger a major amendment to the Biologics License Application (BLA). This will provide the 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). The FDA and Dynavax have both committed to processing this final stage of the review in the most efficient manner possible by maintaining open channels of communication. This timing does not impact the company's plans to launch HEPLISAV-B commercially in the United States in early 2018.