Vical Presents Positive Preclinical Results with Vaxfectin(R)-Formulated, Peptide-based Cancer Vaccine

BOSTON, Sept. 24, 2009 (GLOBE NEWSWIRE) -- Vical Incorporated (Nasdaq:VICL) announced today the presentation of encouraging results from animal studies of a peptide-based cancer vaccine formulated with the company's Vaxfectin(R) adjuvant. Sean M. Sullivan, Ph.D., Vical's Executive Director of Pharmaceutical Sciences, is presenting data at the IIRUSA Vaccines Development Forum (Boston - September 23-25) demonstrating the adjuvant's ability to enhance immune responses of cancer antigen-based vaccines in addition to a broad variety of DNA- and protein-based vaccines against infectious diseases.

"The Vaxfectin(R) adjuvant continues to demonstrate tremendous versatility in both infectious disease and cancer applications," said Alain P. Rolland, Pharm.D., Ph.D., Vical's Executive Vice President of Product Development. "The latest data showed that mice vaccinated with a Vaxfectin(R)-formulated TRP-2 melanoma tumor antigen peptide achieved significant improvements in cellular immune responses, reduced numbers of tumors, and a survival advantage compared with mice receiving control or no treatment. These data encourage further development of additional cancer applications and exploration of partnering opportunities."

Results from a mouse study demonstrated an 88-fold increase in antigen-specific CD8+ T-cell responses at low doses and a 45-fold increase at high doses with a Vaxfectin(R)-formulated peptide-based cancer vaccine compared with unformulated vaccine. The Vaxfectin(R)-formulated cancer peptide also resulted in 7- to 14-fold higher responses than obtained with TRP-2 formulated with Freund's adjuvant. In addition, the Vaxfectin(R)-formulated vaccine demonstrated a clear dose response when used at a constant adjuvant-to-peptide ratio. When evaluated against induced melanoma tumors, mice treated with the vaccine had statistically significantly fewer tumor lesions in the lungs compared with mice receiving no treatment or receiving a Vaxfectin(R)-formulated peptide control treatment. The mice receiving Vaxfectin(R)-formulated vaccine also demonstrated a significant survival advantage compared with untreated mice.

Vaxfectin(R)-formulated vaccines have demonstrated good tolerability and significant immune responses in multiple animal models, including nonhuman primates, and underwent successful initial human testing with the company's H5N1 pandemic influenza DNA vaccines. Vaxfectin(R) has also demonstrated a dose-sparing effect (the ability to achieve the same vaccine effectiveness with lower vaccine doses) with commercial seasonal influenza and government-stockpiled protein-based H5N1 pandemic influenza vaccines.

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 statements about Vical's technologies, the Vaxfectin(R) adjuvant, the TRP-2 peptide-based cancer vaccine, as well as the company's focus, and independent and partnered product candidates. Risks and uncertainties include whether Vical or others will continue development of the TRP-2 peptide-based cancer vaccine, other Vaxfectin(R)-formulated cancer or infectious disease applications, or any other product candidates; whether the TRP-2 peptide-based cancer vaccine will advance to human testing, and if so, whether results in mice will be predictive of results in humans; whether Vical or its collaborative partners will seek or gain approval to market the TRP-2 peptide-based cancer vaccine, other Vaxfectin(R)-formulated applications, or any other 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.

CONTACT:  Vical Incorporated
          Alan R. Engbring
          (858) 646-1127
          www.vical.com