Dynavax Issues Update on HEPLISAV's Regulatory Path, Will Host Call Tomorrow

Dynavax Technologies Corporation DVAX today announced the design of its next large-scale clinical study of HEPLISAV, its investigational adult hepatitis B vaccine, following discussions with the U.S. Food and Drug Administration (FDA or Agency). The planned study, HBV-23, is intended to provide a sufficiently-sized safety database for the Agency to complete its review of Dynavax's Biologics License Application (BLA). It will be an 8,000 subject, Phase 3, observer-blinded, randomized, active-controlled, multicenter trial of the safety and immunogenicity of HEPLISAV compared with Engerix-B(R) in adults 18 to 70 years of age. The primary objectives of HBV-23 will be: -- To evaluate the overall safety of HEPLISAV with respect to clinically significant adverse events; and -- To demonstrate the noninferiority of the peak seroprotection rate (SPR) induced by HEPLISAV to Engerix-B in subjects with type 2 diabetes mellitus. HBV-23 will include 5,500 HEPLISAV subjects and 2,500 Engerix-B subjects, randomized 2:1 and stratified by age and diabetes diagnosis. HEPLISAV subjects will receive two doses at 0 and 1 month, while Engerix-B subjects will receive three doses at 0, 1 and 6 months. All HEPLISAV subjects will be evaluated for safety for one year following the second dose and all potential autoimmune events will be adjudicated by a Safety Evaluation and Adjudication Committee. Immunogenicity assessments will be conducted in a subset of subjects, including those with type 2 diabetes. "Following extensive discussion with FDA, we've finalized a study design that we believe will provide confidence to the Agency regarding HEPLISAV's safety profile, and importantly, will provide Dynavax with the opportunity to prospectively generate additional immunogenicity data in persons with diabetes, a population for whom there is a clear unmet medical need," commented Eddie Gray, Dynavax Chief Executive Officer. Dynavax intends to initiate this study in the first quarter of 2014 and conclude subject visits by the end of 2015 and estimates the external costs of the study to be in the range of $50-55 million. Dynavax's Marketing Authorization Application for HEPLISAV remains on file in Europe. The Company is currently preparing its response to the European Medicines Agency's (EMA) 120-Day List of Questions to be submitted in the fourth quarter of 2013, following which the EMA will provide Dynavax its 180-Day List of Outstanding Issues expected in the first quarter 2014. The 120-Day response will incorporate the target population for HEPLISAV and size of the safety database, and will address Good Manufacturing Practices (GMP) and Good Clinical Practices (GCP)-related items, including questions arising from a recent EMA GCP inspection. Dynavax will continue to work through the European regulatory review process to determine the appropriate next steps, corrective actions, and possible post-approval commitments. The Company anticipates that some of these matters will need to be resolved following issuance of the 180-Day List of Outstanding Issues, which when received, will enable Dynavax to provide further clarification on HEPLISAV's potential path forward in Europe. Engerix-B(R) is a registered trademark of GlaxoSmithKline. Conference Call Tomorrow Dynavax management will host a conference call tomorrow at 8:30 a.m. Eastern Time (5:30 a.m. Pacific Time) and individuals may participate in the conference call by dialing (866) 428-9517 (domestic) or (224) 357-2389 (international). To access a live audio webcast of the conference call, please visit the Company's website at http://investors.dynavax.com/newsevents.cfm