Phase II study of pre-prostatectomy immunotherapy under way

The first of two phase II clinical trials of sipuleucel-T (Provenge), an investigational active cellular immunotherapy for prostate cancer, has been launched.

The study, known as the NEOadjuvant Active Cellular immunotherapy trial (NeoACT), will examine the use of the agent in men with localized prostate cancer who are scheduled to undergo a radical prostatectomy. It is being conducted at the Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco.

Approximately 6 to 7 weeks prior to radical prostatectomy, the 40 participants will be given a full course of three infusions of sipuleucel-T, 2 weeks apart, in a 1-month period. Researchers will measure immune response in the prostatectomy specimens and in the peripheral blood. Following radical prostatectomy, patients will be randomized to receive either a treatment booster or no booster.

The goal of the trial is to better understand the mechanism of action and biology of the agent and to evaluate its efficacy as post-prostatectomy treatment in men at high risk of disease recurrence, according to Dendreon Corp., its manufacturer.

Separately, Dendreon announced that it expects the Independent Data Monitoring Committee to review in October 2008 the interim analysis of overall survival relating to its phase III IMPACT (IMmunotherapy for Prostate AdenoCarcinoma Treatment) clinical trial of sipuleucel-T.

If the required statistical significance is met in interim results, the company said it may modify its biologics license application. If significance is not reached, the study will continue, with final results to be reported in late 2009.