LONG-TERM PAMIDRONATE TREATMENT OF ADVANCED MULTIPLE-MYELOMA PATIENTSREDUCES SKELETAL EVENTS

Purpose: to determine the efficacy and safety of 21 monthly cycles of pamidronate therapy in patients with advanced multiple myeloma. Patien ts and Methods: patients with stage III myeloma and at least one lytic lesion received either placebo or pamidronate 90 mg intravenously adm inistered as a 4-hour infusion monthly for 21 cycles. At study entry, the patients were stratified according to whether they were to receive first-line (stratum 1) or second-line (stratum 2) antimyeloma chemoth erapy. Skeletal events (pathologic fracture, radiation or surgery to b one, and spinal cord compression) and hypercalcemia were assessed mont hly. Results: The results of the first nine previously reported cycles are extended to 21 cycles. Of the 392 randomized patients, efficacy c ould be evaluated in 198 who received pamidronate and 179 who received placebo. After 21 cycles, the proportion of patients who developed an y skeletal event was lower in the pamidronate-group (P = .015). The me an number of skeletal events per year was less in the pamidronate-grou p (1.3) than in placebo-treated patients (2.2; P = .008). Although sur vival was not different between the pamidronate-treated group and plac ebo patients overall, stratum 2 patients who received pamidronate live d longer than those who received placebo (14 v 21 months, P = .041). P amidronate was safe and well tolerated during the 21 cycles of therapy . Conclusion: Long-term monthly infusions of pamidronate as an adjunct to chemotherapy are superior to chemotherapy alone in reducing skelet al events in stage III multiple myeloma patients, and may improve the survival of patients on salvage therapy. (C) 1998 by American Society of Clinical Oncology.