Cell Genesys, Inc. has received a Special Protocol Assessment (SPA) from the US Food and Drug Administration (FDA) for its second Phase 3 clinical trial of Gvax vaccine for prostate cancer. The company's first Phase 3 trial of Gvax vaccine for prostate cancer was initiated in July 2004 and was also granted a SPA by the US FDA.

"The SPAs for our two Phase 3 trials provide Cell Genesys with a well-defined pathway for regulatory submission for our lead product candidate, Gvax vaccine for prostate cancer," stated Joseph J. Vallner, president and chief operating officer of Cell Genesys.

Cell Genesys is currently planning two Phase 3 clinical trials of Gvax vaccine for prostate cancer in hormone-refractory prostate cancer patients with radiologic evidence of metastatic disease. The first trial (VITAL-1 or Vaccine ImmunoTherapy with Allogeneic prostate cancer cell Lines) was initiated in July 2004 and is enrolling chemotherapy naïve, asymptomatic patients without cancer-related pain and is comparing Gvax vaccine to Taxotere (docetaxel) chemotherapy plus prednisone with respect to a survival benefit, a release from the company said.

The second trial (VITAL-2), for which the above-mentioned SPA was recently granted, is expected to begin in the near future and will enrol symptomatic patients with cancer-related pain and will compare Gvax vaccine plus Taxotere chemotherapy to Taxotere chemotherapy plus prednisone with respect to a survival benefit.

The Company has conducted two Phase 2 trials of Gvax vaccine for prostate cancer in patients with hormone refractory metastatic prostate cancer. At the May 2005 American Society for Clinical Oncology (ASCO) meeting, the company reported updated results from its second trial which indicated that in 22 patients receiving a dosing regimen comparable to that being used in Phase 3, the median survival has not yet been reached and will meet or exceed 24.1 months based on the median follow-up time in these patients.