CHICAGO, June 6, 2011 (GLOBE NEWSWIRE) -- Vical Incorporated (Nasdaq:VICL) today announced results from new statistical analyses of data from three previously completed clinical trials of the company's Allovectin® immunotherapy in patients with metastatic melanoma, showing with strong positive correlation that responders lived significantly longer than nonresponders. In a Phase 2 study of high-dose (2 mg) Allovectin® in 127 chemo-refractory or chemo-intolerant patients with metastatic melanoma, the overall survival was 65% at one year, 43% at two years, and 32% at three years. The median overall survival was 18.8 months (95% CI: 14.8 – 26.2 months). Survival among the 15 clinical responders ranged from 18 months to more than seven years (median survival not reached; 95% CI: 35.5 months – not reached). The median overall survival for nonresponders in the Phase 2 study was 16.2 months (95% CI: 13.3 – 21.2 months), which is notably longer than historical survival for other metastatic melanoma treatments, suggesting that these patients also may have derived clinical benefit from Allovectin®.
About Allovectin®
Allovectin® is a systemic immunotherapeutic with a unique mechanism of action that may be complementary to currently approved treatments. It is delivered into a single tumor lesion, but elicits an immune response directed against lesions throughout the body. Among patients with more than one lesion at baseline in the high-dose Phase 2 study, 57% of clinical responders and 17% of clinical nonresponders had tumor responses in noninjected lesions. Vical's ongoing Phase 3 trial is evaluating Allovectin® compared with standard chemotherapy as a first-line therapy in patients with Stage III or IV recurrent metastatic melanoma. The primary endpoint is objective response rate at 24 weeks or more after randomization, and overall survival is a secondary endpoint. Vical completed enrollment in February 2010 of 390 chemo-naive patients randomized on a 2:1 basis for treatment with Allovectin® or chemotherapy (physician's choice of either dacarbazine or temozolomide).
Allovectin® has demonstrated an excellent safety profile in multiple clinical trials. In the high-dose Phase 2 trial, there were no grade 3 or grade 4 drug-related adverse events. Safety has been a hallmark of Allovectin® treatment, and side effects typically have been local and not significant.
The mechanism of action for Allovectin® is applicable to solid tumors other than melanoma, and Vical has conducted early-stage clinical trials of Allovectin® in patients with breast, prostate, colorectal or kidney cancer, chronic lymphocytic leukemia, or squamous cell cancer of the head and neck. AnGes MG, Inc., has licensed rights to commercialize Allovectin® in specified Asian countries, and is primarily interested in developing Allovectin® as a treatment for head and neck cancer, which presents a significant unmet medical need in Asia. Vical estimates that the worldwide market for Allovectin® as a treatment for metastatic melanoma could exceed $500 million annually, and applications for other types of cancer could further expand its total use.
Key Statistical Analysis Conclusions
Vical conducted statistical analyses of results from three completed clinical trials (a high-dose Phase 2, a low-dose Phase 2, and a low-dose Phase 3) of Allovectin® in patients with metastatic melanoma to evaluate the potential for a predictive correlation between response and survival.
- In the high-dose Phase 2 study, time-dependent covariate analysis indicated that responder status strongly predicted survival [hazard ratio = 4.13 (95% CI: 1.67-10.25), score test p-value = 0.002].
- Landmark method analysis (starting at week 24) of Kaplan-Meier survival curves from the high-dose Phase 2 study indicated a significant difference between responders and nonresponders (log rank p-value = 0.036).
- Time-dependent covariate analyses yielded similar results in a completed low-dose (10 mcg) Allovectin® Phase 2 study in patients with metastatic melanoma [hazard ratio = 4.96 (95% CI: 1.52-16.15), score test p-value = 0.008], and in a completed low-dose Allovectin® Phase 3 study in patients with metastatic melanoma [hazard ratio = 3.38 (95% CI: 1.82-6.26), score test p-value < 0.001].
The results were presented by Dmitri D. Kharkevitch, M.D., Ph.D., Vical's Executive Director of Clinical and Medical Affairs, at a poster session Sunday at the 47th Annual Meeting (Chicago, June 3 – 7) of the American Society of Clinical Oncology (ASCO).
About Vical
Vical researches and develops biopharmaceutical products based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases. Potential applications of the company's DNA delivery technology include DNA vaccines for infectious diseases or cancer, in which the expressed protein is an immunogen; cancer immunotherapeutics, in which the expressed protein is an immune system stimulant; and cardiovascular therapies, in which the expressed protein is an angiogenic growth factor. The company is developing certain infectious disease vaccines and cancer therapeutics internally. In addition, the company collaborates with major pharmaceutical companies and biotechnology companies that give it access to complementary technologies or greater resources. These strategic partnerships provide the company with mutually beneficial opportunities to expand its product pipeline and address significant unmet medical needs. Additional information on Vical is available at www.vical.com.
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This press release contains forward-looking statements subject to risks and uncertainties that could cause actual results to differ materially from those projected. Forward-looking statements include whether Vical or others will continue developing Allovectin®; whether the positive correlations seen in earlier trials will be seen in the ongoing Phase 3 trial; whether Allovectin® will be approved as primary treatment for metastatic melanoma in the United States or any other countries; whether the Phase 3 trial will meet its primary endpoint or any other trial endpoints; whether any patients will derive benefit from treatment with Allovectin®; whether Allovectin® will generate revenues exceeding $500 million annually for metastatic melanoma, if any; whether Allovectin® will be successfully developed and commercialized for other solid tumor indications; whether AnGes will develop or commercialize Allovectin® in Asia for head and neck cancer or any other indication; whether any product candidates will be shown to be safe and effective in clinical trials; the timing, nature and cost of clinical trials; whether Vical or its collaborative partners will seek or gain approval to market any product candidates; whether Vical or its collaborative partners will succeed in marketing any product candidates; and additional risks set forth in the company's filings with the Securities and Exchange Commission. These forward-looking statements represent the company's judgment as of the date of this release. The company disclaims, however, any intent or obligation to update these forward-looking statements.