Ascenta Therapeutics announced positive preliminary results from its Phase II study of AT-101 in combination with docetaxel (Taxotere) and prednisone in men with docetaxel refractory, castrate resistant prostate cancer (CRPC). AT-101 is an oral, pan-Bcl-2 inhibitor.
Initial findings from the ongoing open-label, multicenter study demonstrated that AT-101 can be administered safely with docetaxel and prednisone in these patients. Results were released at the 2009 ASCO GU Cancers Symposium in Orlando, Fla. The analysis included data from 37 men with docetaxel-refractory CRPC who were treated with docetaxal (75 mg/m2 q3 weeks), prednisone (5 mg b.i.d. on days 1-21) and AT-101 (40 mg b.i.d. on days 1-3 of each 21-day cycle).
Thirty-eight percent of patients treated had at least a 30% decrease in PSA level and 19% achieved a confirmed partial response.
Investigators also observed clinical responses, based on both PSA and RECIST criteria, including four patients with a confirmed partial response, defined as a PSA decline of 50% or greater.
The most common adverse events included fatigue (50%) and diarrhea (27%), as well as nausea, anorexia, and neutropenia (all 23%).