Cell Genesys terminates Phase III prostate cancer trial

The company has ended the trial as recommended by its independent data monitoring committee (IDMC) which observed an imbalance in deaths between the two treatment arms of the study.

To date, Vital-2 enrolled 408 patients. The IDMC based its recommendation on 114 deaths of which 67 occurred in the Gvax plus Taxotere combination treatment arm and 47 deaths occurred in the Taxotere control arm. At this time, a specific cause for the imbalance in deaths has not been identified and the IDMC reported no new safety issues for Gvax when administered in combination with Taxotere.

The company plans to fully analyze the clinical data from these patients to attempt to understand the potential cause for the higher rate of deaths observed in the Gvax immunotherapy plus Taxotere combination arm, including an assessment of potential imbalances between the two arms of the study such as baseline characteristics and prognostic factors, as well as other treatment variables.

In light of the IDMC’s observation with respect to Vital-2, the company has requested that the IDMC perform a previously unspecified futility analysis of Vital-1, the other Phase III clinical trial of Gvax immunotherapy for prostate cancer. The company expects the results of the Vital-1 futility analysis in September 2008.

Stephen Sherwin, chairman and CEO of Cell Genesys, said: “We are currently notifying all participating clinical trial sites and regulatory agencies that enrollment of new patients into Vital-2 has been suspended as has treatment with Gvax immunotherapy for prostate cancer of patients enrolled in the study.”