Vical Presents Positive Preclinical Results With Vaxfectin-Formulated, Peptide-Based Cancer Vaccine

Vical has presented encouraging results from animal studies of a peptide-based cancer vaccine formulated with the Vaxfectin adjuvant. The study demonstrates 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.

Alain Rolland, executive vice president of product development at Vical, said: “The Vaxfectin adjuvant continues to demonstrate tremendous versatility in both infectious disease and cancer applications. The latest data showed that mice vaccinated with a Vaxfectin-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-formulated peptide-based cancer vaccine compared with unformulated vaccine. The Vaxfectin-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-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-formulated peptide control treatment. The mice receiving Vaxfectin-formulated vaccine also demonstrated a significant survival advantage compared with untreated mice.

Vaxfectin-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 has also demonstrated a dose-sparing effect with commercial seasonal influenza and government-stockpiled protein-based H5N1 pandemic influenza vaccines.