THE "NEW" PROSTATE CANCER INFOLINK

The only other significant news story this morning covers the publication of

• Phase I/II data on use of Cell Genesys’s immunotherapeutic agent GVAX in patients with metastatic disease

Higano et al. have just published the results of a Phase I/II clinical trial of GVAX, a GM-CSF-secreting, allogeneic, cellular immunotherapy, in treatment of men with metastatic, hormone-refractory prostate cancer. These data (reported in the journal Cancer) have previously been presented at medical meetings, and GVAX is currently in Phase III clinical trials in combination with docetaxel and prednisone (the so-called VITAL 1 and VITAL 2 trials).

The trial was an open-label, multicenter, dose-escalation study evaluating multiple dose levels of GVAX immunotherapy. Dose levels ranged from 100 × 10⁶ cells q28d × 6 to 500 × 10⁶ cells prime/300 × 10⁶ cells boost q14d × 11. Endpoints included safety, immunogenicity, overall survival, radiologic response, PSA kinetics, and serum GM-CSF pharmacokinetics. Eighty men, with a median age of 69 years, were treated. The most common adverse effect was injection-site erythema. Overall, the immunotherapy was well tolerated. A maximal tolerated dose of GVAX was not established in this trial. The median survival time was 35.0 months in the high-dose group, 20.0 months in the mid-dose group, and 23.1 months in the low-dose group. PSA stabilization occurred in 15/80 patients (19 percent, and a > 50% decline in PSA was seen in one patient. 

The authors conclude that this form of immunotherapy was well tolerated, and that immunogenicity and overall survival varied by dose. For additional information, see the press release issued by Cell Genesys and the company’s web site.