Dynavax Presents Clinical Data From Lead Cancer Immunotherapy Candidate, SD-101, at ASH Annual Meeting

BERKELEY, CA--(Marketwired - Dec 5, 2015) - Dynavax Technologies Corporation (NASDAQ: DVAX) today announced clinical data from an ongoing Phase 1/2 clinical trial evaluating intratumoral administration of SD-101 in the treatment of low-grade lymphoma. The combination of intratumoral SD-101 and low-dose irradiation resulted in tumor regression in untreated tumor sites as well as in the treated tumors. Treatment was well-tolerated and changes in T cell populations consistent with stimulation of anti-tumor immunity were observed in the treated lesions. These data were presented in a poster session on Saturday at the 57^th American Society of Hematology (ASH) Annual Meeting in Orlando, Florida.

Data from the dose escalation phase of the study were reported from 13 evaluable patients. None of the patients had received prior treatment for their low-grade lymphoma. The primary endpoints of the trial are maximum tolerated dose (MTD) and evaluation of the safety of intratumoral SD-101 in combination with low dose radiotherapy. In addition, the trial is evaluating anti-tumor activity, pharmacodynamics, and duration of response. Doses ranged from 1 mg to 8 mg per injection in successive cohorts.

Key findings presented include:

• Of the 13 evaluable patients treated across all dose levels, 11 patients (84.6%) were observed to have regression of non-treated, non-irradiated tumors at Day 90 (reductions range from 0.9% to 48.2 %), indicating abscopal effect. One patient reached a partial response (PR) per Cheson criteria at Day 180.
  
  
• There were no dose limiting toxicities (DLT) and an MTD was not identified. The most common treatment-related adverse events were local injection site reactions and flu-like symptoms, including fever, chills, and myalgia. There have been no serious adverse events related to the treatment.
  
  
• T cells increased at the treated site in 7 of 10 patients ranging from > 300% to 18%. Both CD4 and CD8 T cells increased in 5 of 7 patients. In addition, TReg cells were depleted at the treated site an average of 22.3 + 9.5% in 8 of 10 patients. Tfh cells showed a significant reduction of 83.3 + 9.9%.

"The first report of clinical responses and changes in T cell populations presented today provide encouraging evidence that immune modulating therapies such as SD-101 can be delivered directly into a tumor to promote changes in the tumor microenvironment and induce a systemic anti-tumor immune response. We look forward to providing future updates as this study and other studies evaluating SD-101 in combination with checkpoint blockade progress," said Eddie Gray, Chief Executive Officer of Dynavax.

To see the poster presentation in its entirety, please visit the Presentations section located in the Investor section of the Dynavax website.

About SD-101

SD-101, the subject of ASH abstract 1539, is Dynavax's proprietary, second-generation, TLR 9 agonist CpG-C class oligodeoxynucleotide. SD-101 activates multiple anti-tumor activities of innate immune cells and activates plasmacytoid dendritic cells to stimulate T cells specific for antigens released from dying tumor cells. TLR9 agonists such as SD-101 enhance T and B cell responses and provide potent Type 1 interferon induction and maturation of plasmacytoid dendritic cells to antigen-presenting cells. SD-101 is being evaluated in several Phase 1/2 oncology studies to assess its preliminary safety and activity.

For information about SD-101 trials that are currently recruiting patients, please visit www.clinicaltrials.gov.

About Dynavax

Dynavax, a clinical-stage biopharmaceutical company, discovers and develops novel vaccines and therapeutics in the areas of infectious and inflammatory diseases and oncology. Dynavax's lead product candidates are HEPLISAV-B™, a Phase 3 investigational adult hepatitis B vaccine and SD-101, an investigational cancer immunotherapeutic currently in several Phase 1/2 studies. For more information, visit www.dynavax.com.

Dynavax Forward Looking Statements

This press release contains "forward-looking" statements, including expectations for the conduct and timing 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, initiate one or more studies, enroll a sufficient number of subjects and ultimately complete any study, 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.