Long-term survival data in phase II trial of GVAX vaccine reported at conference.(Brief Article)

2002 JUN 12 - (NewsRx.com & NewsRx.net) -- Cell Genesys, Inc. (CEGE) has reported encouraging long-term survival data from a phase II multicenter clinical trial of GVAX prostate cancer vaccine which demonstrates a dose-dependent trend toward prolonged survival in patients with hormone-refractory prostate cancer metastatic to bone. In the 34-patient study, 7 of 10 (70%) patients receiving the higher-dose level of the vaccine are alive 2.5 years after treatment (median survival >30 months).

Of the 24 patients receiving the lower dose of the vaccine, 9 of 22 patients (41%) are alive 2.5 years after treatment (median survival 22 months), and 2 were lost to follow-up. These results compare favorably with the reported median survival of 7-11 months for hormone-refractory prostate cancer patients with bone metastases who are treated with chemotherapy, the current standard of care for this patient group.

The dose-dependent improvement in survival was consistent with a previously reported improvement in time to disease progression measured by both radiologic and prostate-specific antigen (PSA) endpoints also in favor of the high-dose group. Treatment with GVAX vaccine was safe and well-tolerated. These data were presented at the American Society of Clinical Oncology (ASCO) Meeting in Orlando, Florida by Jonathan Simons, MD, of Emory University.

The study reported at ASCO employed a 6-month treatment regimen in which

patients received an initial "priming" dose of GVAX prostate cancer vaccine followed by 12 biweekly "booster" doses using either a high-dose or threefold lower-dose regimen. The two dose groups were comparable with respect to disease stage, duration and prior treatment for their prostate cancer as well as other demographic criteria. The vaccine, which is a nonpatient-specific, "off-the-shelf" product was administered by an intradermal injection into the skin of the arms and legs in an outpatient clinic setting. Patients were observed for evidence of vaccine efficacy and safety using standard clinical and radiologic tests. No other cancer therapies aside from the GVAX vaccine were administered during either the 6-month treatment or post-treatment follow-up period.

"These encouraging data have prompted Cell Genesys to plan a phase III trial of GVAX prostate cancer vaccine which we expect to initiate in the first half of 2003. Prior to initiating ...