Dynavax Reports Data for Phase 1b/2 Trial of SD-101 in Combination with KEYTRUDA® (pembrolizumab) in Advanced Melanoma at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting

Overall Response Rate (ORR) of 70% and 6-month Progression Free Survival (PFS) rate of 76% in Patients Naïve to Anti-PD-1 Treatment who Received the ≤ 2mg Dose of SD-101

Combination showed Similar Rates of Immune-related Adverse Events as Seen with KEYTRUDA Monotherapy

2mg SD-101 Dose Selected for Phase 3

BERKELEY, CA, USA I June 04, 2018 I Dynavax Technologies Corporation (NASDAQ:DVAX) today announced data 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) in patients with advanced melanoma.

The company reported results on a total of 69 patients comparing two doses of SD-101, ≤ 2mg (n=30) versus 8mg (n=39) administered by intratumoral injection. These data are being presented in poster and discussion session today at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting, in Chicago, IL. The primary endpoints of this dose-expansion/dose-finding study are safety and preliminary efficacy. The results of this study showed a 70% overall response rate (ORR) in advanced melanoma patients who received the ≤ 2 mg dose of SD-101 in up to four lesions versus a 38% ORR in the group receiving the 8 mg dose of SD-101 in one lesion. The combination of SD-101 and KEYTRUDA was well tolerated with adverse events related to SD-101 being transient, mild to moderate flu-like symptoms.

“These data provide further evidence of the potential for SD-101 to improve responses in first-line advanced melanoma patients in combination with an anti-PD-1 therapy,” commented Eddie Gray, Chief Executive Officer. “Our studies continue to demonstrate the potential value of SD-101 across multiple tumor types. We plan to build upon this momentum and update our progress with additional data planned for a medical conference later in the year.”   

Highlights from Poster Presentation (Abstract #9513)   

• Overall response rate (ORR) of 70% (21 of 30), with a complete response (CR) rate of 17%, for advanced melanoma patients who received the ≤ 2 mg dose of SD-101 in up to four lesions
• ORR of 38% (15 of 39) in patients who received the 8 mg dose of SD-101 in one lesion
• Durable response in patients who received ≤ 2 mg dose of SD-101 with 74% 6-month progression free survival (PFS) rate
• Observed responses in injected lesion(s) and distant lesions, including visceral metastases in the liver
• Responders included 8 of 10 PD-L1 negative patients in the ≤ 2 mg dose cohort
• AEs related to SD-101 treatment were transient, mild to moderate flu-like symptoms at both the ≤ 2mg and the 8 mg dosing levels
• No increase in the frequency of immune-related adverse events over individual monotherapies reported in other studies^1,2 nor evidence of any  new safety signals

Additional details on response rates based on patient characteristics including stage of disease, ECOG score, and PD-L1 status are also included in the poster presentation which can be accessed here.
             
“We are moving forward with the 2mg dose of SD-101 for our Phase 3 trial which we believe is the optimal dose based on these efficacy, safety and biomarker data showing increased immune activation consistent with the biology of TLR9 activation.  We continue to collect and analyze data from this trial to finalize details of the Phase 3 study design,” stated Rob Janssen, Chief Medical Officer.

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

Analyst/Investor Presentation
Today at 6:30pm CDT, Dynavax will host a presentation for analysts and investors. The presentation will be available via live webcast only and can be accessed in the “Investors and Media” section of the company’s website at www.dynavax.com.

About SYNERGY-001 (KEYNOTE-184)
SYNERGY-001, previously referred to as MEL-01, is the dose-escalation and expansion study of SD-101 in combination with KEYTRUDA which 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.

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], was approved by the United States Food and Drug Administration in November 2017 for prevention of infection caused by all known subtypes of hepatitis B virus in adults age 18 years and older. 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.

1. Ribas A, et al. JAMA. 2016;315(15):1600-1609.
2. Specenier P. Expert Opin Biol Ther. 2017;17(6):765-780.