Dynavax Technologies Corporation (NASDAQ:DVAX) announced the presentation of findings in patients with metastatic melanoma in the dose escalation phase of an 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. Results evaluating 19 patients for efficacy and 22 patients for safety were presented in a poster at the 2017 American Society of Clinical Oncology Annual Meeting in Chicago:
- In 7 anti-PD-1/L1-naïve patients, SD-101 used in combination with KEYTRUDA resulted in an overall response rate (ORR) of 100%, with a complete response (CR) rate of 29%. This is a meaningful increase over use of KEYTRUDA alone, which has already shown a 33% ORR, with a 6% CR.(1)
- In 12 patients with advanced (stage IIIc/IV) melanoma who had previously failed on anti-PD-1 treatment, introduction of SD-101 resulted in tumor shrinkage in 42% of patients, with 17% having a partial response (PR), indicating an anti-tumor immune response generated by SD-101.
- The combination of SD-101 and KEYTRUDA in this study, mobilized both innate and adaptive immune response in study participants.
- Tumor shrinkage was observed in non-injected visceral lesions.
“Having 7 out of 7 patients naïve to anti-PD-1/L1 treatment responding is very encouraging,” said Antoni Ribas, M.D., Ph.D., of the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles, and lead investigator. “These results are supported by tumor shrinkage in patients who had previously progressed on anti-PD-1 treatment and by confirmatory laboratory biomarker assessments in tumor biopsies. If these clinical results are sustained in the ongoing trial, this combination, which mobilizes both innate and adaptive immune responses in patients, could represent an important advancement in immuno-oncology.”
SD-101 in combination with KEYTRUDA generally was well-tolerated. No dose-limiting toxicities of the combination were observed in any dose cohort, and a maximum tolerated dose (MTD) was not identified. The most common treatment-emergent adverse events were injection site reactions and transient grade 1 to 2 flu-like symptoms, including fever, chills and myalgia. The study also includes biomarker assessments, suggesting that treatment with SD-101 and KEYTRUDA resulted in increased tumor-infiltrating lymphocytes and decreased Th2 in tumor biopsies, consistent with induction of an antitumor immune response.
Shares of Dynavax are up nearly 6% to $6.25 in after-hours trading Friday. DVAX has a 1-year high of $17.50 and a 1-year low of $3.20. The stock’s 50-day moving average is $5.58 and its 200-day moving average is $4.95.
Dynavax Technologies Corp. is a clinical-stage biopharmaceutical company that uses toll-like receptor biology to discover and develop novel vaccines and therapeutics. The company’s development programs are organized under its three areas of focus: vaccine adjuvants, cancer immunotherapy, and autoimmune and inflammatory diseases. Its lead product candidate is HEPLISAV, a Phase III investigational adult hepatitis B vaccine. The company’s other products under pipeline are SD-101, DV1179 Autoimmune Disease and AZD1419 Asthma Therapy.