Advanced prostate cancer combination treatment fails to improve survival

February 1, 2011

Results of a phase III trial failed to confirm data from a phase II study suggesting that the addition of high-dose oral calcitriol (DN-101) to docetaxel (Taxotere) confers a survival advantage and reduces toxicity versus treatment with docetaxel alone in men with progressive castration-resistant prostate cancer (CRPC).

Key Points

New York-Results of a phase III trial failed to confirm data from a phase II study suggesting that the addition of high-dose oral calcitriol (DN-101) to docetaxel (Taxotere) confers a survival advantage and reduces toxicity versus treatment with docetaxel alone in men with progressive castration-resistant prostate cancer (CRPC).

ASCENT2 randomized 953 men with CRPC to treatment with the same regimen investigated in the phase II ASCENT study (the ASCENT-treated arm): DN-101, 45 mcg; docetaxel, 36 mg/m2; and dexamethasone (Baycadron, DexPak), 24 mg weekly for 3 out of every 4 weeks; or a control arm receiving prednisone, 5 mg twice per day, with docetaxel, 75 mg/m2 and dexamethasone, 24 mg, once every 3 weeks.

In the final survival analysis conducted in May 2008, median overall survival was 16.8 months for the ASCENT2 arm versus 19.9 months for the control group. In further analyses adjusting for a variety of baseline prognostic factors or considering only cancer-related death, the survival difference favoring the control arm remained statistically significant.

A finding from ASCENT suggesting that DN-101 had a protective effect on gastrointestinal and thrombotic events was also not confirmed, reported Dr. Scher, chief of the genitourinary oncology service at Memorial Sloan-Kettering Cancer Center, New York.