Combined Analysis of Two Multicenter, Randomized, Placebo-Controlled Studies of Pamidronate Disodium for the Palliation of Bone Pain in Men With Metastatic Prostate Cancer

Abstract

Purpose: Bone metastases occur in approximately 80% of patients with advanced prostate cancer. Pain is common in these patients. The purpose of this study was to evaluate the effect of an intravenous bisphosphonate, pamidronate disodium, on pain control in metastatic prostate cancer patients.Patients and Methods: Two multicenter, double-blind, randomized, placebo-controlled trials were conducted in patients with bone pain due to metastatic prostate cancer, with disease progression after first-line hormonal therapy. Intravenous pamidronate disodium (90 mg) or placebo was administered every 3 weeks for 27 weeks. Efficacy was measured via self-reported pain score (Brief Pain Inventory), analgesic use, the proportion of patients with a skeletal-related event (SRE; defined as pathologic fracture, radiation or surgery to bone, spinal cord compression, or hypercalcemia), and a pilot quantitative measurement of mobility. Laboratory evaluations included serum prostate-specific antigen, interleukin-6, bone alkaline phosphatase, and urinary bone resorption markers.Results: Results of the two trials were pooled. There were no sustained significant differences between the pamidronate and placebo groups in self-reported pain measurements, analgesic use, proportion of patients with an SRE, or mobility at week 9 or 27. Urinary bone resorption markers were suppressed in the pamidronate group compared with placebo.Conclusion: Pamidronate disodium failed to demonstrate a significant overall treatment benefit compared with placebo in palliation of bone pain or reduction of SREs. Evaluation of more potent bisphosphonates in patients with prostate cancer is warranted.