Phase II trial of weekly patupilone in patients with castration-resistant prostate cancer.

BACKGROUND

Drug resistance mechanisms can reduce response rate and duration in men with castration-resistant prostate cancer (CRPC) receiving docetaxel-based therapy. Patupilone (epothilone B), a microtubule-targeting agent, may be unaffected by some resistance mechanisms. Therefore, a phase II study assessed the patupilone safety and activity in CRPC patients with and without previous chemotherapy.

METHODS

CRPC patients received patupilone 2.5 mg/m(2) weekly for 3 weeks of a 4-week cycle. Patients were required to have measurable disease or prostate-specific antigen (PSA) progression (levels>20 ng/ml).

RESULTS

All 45 enrolled patients (median age, 69 years) were safety and response assessable. Sixty-four percent had previous chemotherapy (55% had previous taxane therapy). Patients received a median of three patupilone cycles. Patupilone was generally well tolerated. Ten (22%) patients experienced grade 3 diarrhea, six (13%) grade 3 fatigue, and one (2%) grade 3 neuropathy with no neutropenia or thrombocytopenia incidence. Six (13%) patients had >or= 50% decline in PSA (three had previous taxane therapy). No patient with measurable disease had a response. Median overall survival was 13.4 months.

CONCLUSIONS

The safety profile of weekly patupilone in CRPC patients compares favorably with that of other microtubule inhibitors. At the dose and schedule tested, patupilone demonstrated minimal activity in CRPC.