Dynavax to Present New Data for SD-101 in Combinat

Abstract Data Show Overall Response Rate of 60% in 25 Advanced Melanoma Patients Naïve to Anti-PD-1 Therapy

Poster Presentation to Include Data from a Total of over 50 Patients and Will Compare SD-101 at Two Dose Levels

BERKELEY, Calif., May 16, 2018 (GLOBE NEWSWIRE) -- Dynavax Technologies Corporation (NASDAQ: DVAX ) announced today that data will be presented from its ongoing Phase 1b/2 study investigating SD-101, Dynavax's intratumoral TLR9 agonist, in combination with KEYTRUDA ^® (pembrolizumab), an anti-PD-1 therapy developed by Merck (known as MSD outside the United States and Canada).  Data on patients with advanced melanoma who are naïve to anti-PD-1 therapy is the subject of a poster presentation and will be highlighted in a poster discussion session at the 2018 American Society for Clinical Oncology (ASCO) Annual Meeting, being held June 1-5, 2018 in Chicago, IL.

The abstract for the poster titled “Phase 1b/2, open label, multicenter, study of the combination of SD-101 and pembrolizumab in patients with advanced melanoma who are naïve to anti-PD1 therapy” has been posted on the 2018 ASCO Annual Meeting website, here . The abstract summarizes efficacy data on 25 patients that were available at the time of abstract submission in early February and shows an overall response rate (ORR) of 60%.  The combination reported low rates of Grade 3-4 treatment-related adverse events and no evidence of an increased rate of immune-related adverse events. The poster at ASCO in June will present efficacy data from over 50 patients comparing two doses of SD-101, 2mg in 1-4 lesions versus 8mg in a single lesion.

The details of the poster presentation and discussion session are as follows:

Phase 1b/2, open label, multicenter, study of the combination of SD-101 and pembrolizumab in patients with advanced melanoma who are naïve to anti-PD-1 therapy

About MEL-01 (KEYNOTE-184) The dose-escalation and expansion study of SD-101 in combination with KEYTRUDA includes patients with histologically or cytologically confirmed unresectable Stage IIIC/IV melanoma. The primary endpoints of the trial are safety and preliminary efficacy of intratumoral SD-101 in combination with KEYTRUDA. In addition, biomarkers are being evaluated.

About SD-101 SD-101, the Company's lead clinical candidate, is a proprietary, second-generation, Toll-like receptor 9 (TLR9) agonist CpG-C class oligodeoxynucleotide. Dynavax is evaluating this intratumoral TLR9 agonist in several clinical studies to assess its safety and activity, including a Phase 2 study in combination with KEYTRUDA® (pembrolizumab), an anti-PD-1 therapy, in patients with advanced melanoma and in patients with head and neck squamous cell cancer, in a clinical collaboration with Merck. Dynavax maintains all commercial rights to SD-101.

About Dynavax Dynavax is a fully-integrated biopharmaceutical company focused on leveraging the power of the body's innate and adaptive immune responses through toll-like receptor (TLR) stimulation. Dynavax discovers and develops novel vaccines and immuno-oncology therapeutics. The Company’s first commercial product, HEPLISAV-B® [Hepatitis B Vaccine (Recombinant), Adjuvanted], is approved in the United States. Dynavax's lead immunotherapy product, SD-101, is an investigational cancer immunotherapeutic currently being evaluated in Phase 1/2 studies and its second cancer immunotherapeutic, DV281, is in Phase 1 development. For more information, visit www.dynavax.com .

Forward Looking Statement This press release contains "forward-looking" statements, including statements regarding the conduct of clinical trials of SD-101. Actual results may differ materially from those set forth in this press release due to the risks and uncertainties inherent in our business, including whether we can timely provide adequate clinical supplies; initiation, enrollment and completion of clinical trials of SD-101; the results of clinical trials and the impact of those results on the initiation or continuation of subsequent trials and issues arising in the regulatory process; the ability to successfully develop and commercialize SD-101; and whether or not Dynavax and parties with whom we are collaborating may reach any future agreement on further studies or a more extensive collaboration beyond the clinical trials contemplated under the existing agreements, as well as other risks detailed in the "Risk Factors" section of our current periodic reports with the SEC. We undertake no obligation to revise or update information herein to reflect events or circumstances in the future, even if new information becomes available. Information on Dynavax's website at www.dynavax.com is not incorporated by reference in our current periodic reports with the SEC.

KEYTRUDA is a registered trademark of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.