Cell Genesys' Phase I Gvax Vaccine

Cell Genesys has announced Phase I trial data of its first-generationGvax vaccine, consisting of irradiated tumor cells genetically modified to secrete granulocyte-macrophage colony stimulating factor, in melanoma patients. The results appear in the latest Proceedings of the National Academy of Sciences (October 27).

The 21-patient trial showed that Gvax had potent antitumor immunity in 11 of 16 patients, as seen by dense infiltration of immune cells into metastatic tumors. Antitumor T cells and antibodies specific for melanoma and destruction of tumor blood vessels were also observed.

Three Phase I/II trials of second-generation Gvax for melanoma, lung cancer and prostate cancer are underway, and positive results have already been seen in the latter. The second-generation compound has an advantage over first-generation compounds in that it takes less than 24 hours to manufacture for each patient, compared to up to two months previously, as the retroviral gene delivery system has been replaced with an adenoviral gene delivery system.