A Phase IIa trial of weekly EPO906 in patients with hormone-refractory prostate cancer (HPRC)

4563 Background: Single-agent taxanes have demonstrated clinical activity in HPRC; however, the median duration of response is relatively short. The epothilone EPO906 is a potent microtubule stabilizer that is not a substrate for multidrug-resistance protein and has demonstrated clinical cytotoxic activity in taxane-sensitive, -resistant, and refractory tumors. Thus, EPO906 may be an appropriate alternative to taxane therapy in patients (pts) with HRPC. In a phase IIa study, we investigated the safety and efficacy of weekly EPO906 in these pts. Methods: Pts with histologically proven disease with documented metastases or prostate-specific antigen (PSA) progression > 20 ng/mL were enrolled. Pts could have received ≤ 1 prior chemotherapy regimen for hormone-resistant disease. Pts were maintained on androgen ablation therapy or had undergone an orchiectomy. EPO906 2.5 mg/m2 was administered via a 5-min IV infusion once weekly for 3 wks followed by 1 wk of rest for 6 cycles. Results: A total of 37 pts with a ...