Phase II Trial of Gemcitabine, Prednisone, and Zoledronic Acid in Pretreated Patients with Hormone Refractory Prostate Cancer

ObjectivesTo investigate the impact on biochemical and objective response and on pain improvement of gemcitabine, prednisone, and zoledronic acid in patients with hormone-refractory prostate cancer (HRPC), previously treated with docetaxel-based regimens.MethodsThe patients were treated with gemcitabine 1000 mg/m2 every 14 days, prednisone 10 mg orally on days 1 to 7 and 14 to 21, and zoledronic acid every 4 weeks. Changes in prostate-specific antigen levels, tumor response, and toxicity were evaluated every month. The pain response, based on pain reduction and analgesic drug reduction, was assessed during therapy.ResultsA total of 22 men (median age 65 years) were treated. Overall, 5 patients (23%) achieved a 50% or greater reduction in prostate-specific antigen level after two cycles; a partial response was observed in 1 (14%) of 7 patients with measurable disease, and 3 (43%) of 7 had stable disease. Of the 22 men, 23% had pain improvement. The most important hematologic toxicity was neutropenia (grade 3 in 18%).ConclusionsThe combination of gemcitabine, prednisone, and zoledronic acid appears to be associated with biochemical response, pain improvement, and good safety in pretreated patients with HRPC.