Prospective randomized trial of dichloromethylene bisphosphonate (clodronate) in patients with multiple myeloma requiring treatment. A multicenter study

Characteristic features of multiple myeloma are bone resorption, osteoporosis and osteolytic lesions. Bisphosphonates can inhibit osteoclast activity and bone resorption. In this controlled randomized multicenter trial the effect of the bisphosphonate clodronate on the progression of bone involvement in multiple myeloma was evaluated. Patients and Methods: 170 patients with multiple myeloma requiring treatment and with bone involvement were recruited and randomized, All patients received 15 mg/m(2) i.v. melphalan on day 1 and 60 mg/m(2) p.o. predisone on days 1-4 every 4 weeks, Patients randomized to the bisphosphonate arm received 1,600 mg clodronate p.o./day for 1 year. Bone response was evaluated on the basis of X-ray controls of the skeleton at baseline, 6, and 12 months staging. In addition chemotherapy response, blood chemistry, cytology, pain, and analgesic drug consumption were documented. Results: After one year of treatment there was a higher bone response in the clodronate group (13%) when compared to the control group (6%, n.s.). The difference was mainly due to the change of the osteolytic lesions. Hypercalcemia was observed more often in the control group. The number of progressive sites was lower in the clodronate group (mean 0.49 vs. 0.66, result after one year, p=0.09). The bone resorption index was significantly reduced in the clodronate group, but not in the control group. A reduction of pain and analgesic consumption was observed under clodronate treatment. Conclusion: Oral clodronate as a supplement to melphalan plednisone in multiple myeloma can reduce the number of progressive osteolytic lesions, hypercalcemia, and the bone resorption. A reduction of pain and analgesic consumption was observed in this study.