The preclinical studies were conducted in a melanoma mouse model, which is commonly used to evaluate experimental cancer treatments. Mice were treated with an experimental version of the Gvax cancer vaccine, and a soluble chimeric VEGF decoy receptor after challenge with B16 melanoma cells.
In the studies, tumor-bearing mice treated with a Gvax cancer vaccine combined with VEGF blockade (Avastin) had a statistically significant 48% improvement in the median duration of survival, compared to controls which were not seen in mice treated with VEGF blockade alone or Gvax cancer vaccine alone.
The studies also showed that VEGF blockade enhanced the activity of dendritic cells, a type of immune cell that is critical to a successful vaccine response, thereby providing a possible explanation for the synergistic antitumor activity observed.
“The preclinical studies reported today demonstrate the potential benefits of combining Gvax cancer vaccines with VEGF blockade,” stated Dr Peter Working, senior vice president of R&D at Cell Genesys. “We believe that this combination of immunotherapy and blockade of tumor angiogenesis represents a promising approach to the treatment of cancer.”
Clinical trials of Gvax cancer vaccines are underway for multiple types of cancer, including prostate cancer, lung cancer, pancreatic cancer, leukemia and myeloma.