Safety and efficacy of sorafenib in patients with castrate resistant prostate cancer: A Phase II study

PurposeWe determined the safety and efficacy of sorafenib in patients with castrate resistant prostate cancer (CRPC).MethodsSixty-four chemotherapy and radiotherapy naïve patients with CRPC received 400 mg sorafenib orally twice daily in 6-week cycles. All patients had bone metastasis, while 16 had lymph node-, 9 had liver-, and 10 had lung metastases. Treatment was continued until disease progression or excessive toxicity.ResultsAll patients were assessable for response. A median of 6.4 consecutive cycles was administered per patient. Median overall survival for all patients was 14.6 months (confidence interval [CI], 8.2–22.2). No complete response (CR) occurred. Of the 35 patients with measurable extraosseous disease, 7 (20%) had a partial response. Overall, 13 patients (20.3%; 95% CI, 4%–32%) achieved a 50% or greater reduction (partial response [PR]) in prostate-specific antigen (PSA) level after two cycles. The median response duration was 2.5 months (95% CI, 1.4 to 4.8), and the median time to progression was 5.9 months (95% CI 3.6 to 7.6). There was no treatment-related death. Toxicities were well tolerated.ConclusionsSorafenib demonstrated some antitumor activity. Further studies are necessary to determine a subgroup of patients who would likely respond better to sorafenib.