Randomized phase II trial of patupilone plus prednisone versus docetaxel plus prednisone in patients with chemotherapy-naïve, metastatic, castrate-resistant prostate cancer (CRPC).

4553 Background: Docetaxel (Doc) + prednisone is considered the standard of care in first-line treatment of patients (pts) with CRPC. However, response rates are low and response duration is short. Patupilone (EPO906, Epothilone B), a novel microtubule-targeting agent with 3–20 times greater potency than taxanes in vitro and in vivo, has shown early activity in chemo-naive and docetaxel-resistant CRPC pts. Methods: In stage I of an open-label, multicenter, phase II trial, chemo-naive pts with CRPC (WHO PS ≤2) receiving oral prednisone 5 mg twice daily were randomized to receive patupilone IV 10 mg/m2 every 3 weeks (q3w) or Doc 75 mg/m2 q3w. The main endpoints were prostate-specific antigen (PSA) response rate and safety. Results: Baseline demographics of the 67 stage 1 pts were similar in the patupilone arm (n=34; median age 67 years [yrs; range 53–81 yrs]) and the Doc arm (n=33; median age 67 yrs [range 52–83 yrs]). 57 pts were evaluable for PSA response analysis. The baseline median PSA value was 72 ng/...