Cell Genesys Inc announced that enrolment has been initiated for a multi-centre phase 2 clinical trial of GVAX lung cancer vaccine in patients with advanced-stage bronchoalveolar carcinoma (BAC), one of the four principal subtypes of non small-cell lung cancer (NSCLC).

This trial is being conducted and sponsored by the Southwest Oncology Group (SWOG), a cooperative clinical trials group of the National Cancer Institute. The trial is the second of two phase 2 studies designed to expand on the encouraging results of an earlier phase 1/2 trial of GVAX lung cancer vaccine in advanced, heavily pre-treated patients which among other findings suggested that BAC may be particularly responsive to the vaccine.

Approximately 100 patients with BAC are expected to be enrolled in the new study at 15 to 20 medical centres across the US.

In other news, Cell Genesys confirmed that it is in the final stages of preparation of clinical trial sites to initiate the first phase 3 trial of GVAX prostate cancer vaccine and that the company is finalizing its efforts to open the study for enrolment during the next month.

Cell Genesys recently received a Special Protocol Assessment (SPA) from the Food and Drug Administration (FDA) for this protocol, which provided FDA confirmation that the trial design would adequately support a product registration application. This trial, called VITAL-1, will compare GVAX vaccine to chemotherapy with docetaxel (Taxotere) plus prednisone in patients with metastatic hormone-refractory prostate cancer with respect to survival benefit.

A second phase 3 trial called VITAL-2, which will compare GVAX vaccine plus chemotherapy to chemotherapy alone, is currently in the planning stage and is expected to start in the late 2004/early 2005 timeframe.

"We are pleased to collaborate with the Southwest Oncology Group and NCI in the phase 2 BAC trial and appreciate their support of our GVAX lung cancer vaccine programme," stated Joseph J Vallner, president and chief operating officer of Cell Genesys. "Bronchoalveolar lung cancer is generally less responsive to chemotherapy and therefore represents a subtype of lung cancer for which new treatment strategies are urgently needed," he added.

The results of the previous phase 1/2 clinical trial of GVAX lung cancer vaccine in advanced NSCLC that supported the advancement of the product into further clinical development were published in the February 18, 2004 issue of the Journal of the National Cancer Institute. Of 33 treated patients, the majority of whom had failed prior chemotherapy and/or radiation therapy, three patients (9 per cent) experienced complete responses (complete disappearance of tumour) with a median duration of response of 17.8 months.

Of these three patients, two were noted to have BAC and were among only three patients with this diagnosis treated in the trial. The median survival of all 33 treated patients was 11.6 months, which compares favourably to the reported median survival for the approved second-line chemotherapy, docetaxel (Taxotere). These results led Cell Genesys last year to initiate a follow-on Phase 2 trial in all subtypes of NSCLC which has enrolled over 70 patients to date and is expected to complete accrual later this year, as well as the phase 2 BAC trial announced.