Efficacy And Side-Effect Profile Of Long-Term Bisphosphonate Therapy In Patients (Pts) With Multiple Myeloma (Mm): Mrc Myeloma Ix Study Results.

8015 Background: Bisphosphonates (BPs) are recommended in pts with osteolytic lesions from MM. However, data on the long-term efficacy and safety of BPs beyond 2 y is somewhat limited. The MRC Myeloma IX study has already revealed significant overall survival (OS) and progression-free survival (PFS) benefits for zoledronic acid (ZOL) over clodronate (CLO) in MM pts (N = 1960) initiating chemotherapy (Morgan GJ, et al. Lancet. 2010). We now report the efficacy and safety of BP therapy with long-term follow-up. Methods: Newly diagnosed MM pts were randomized to ZOL (4 mg IV q 21-28 days) or CLO (1600 mg/day PO) plus antimyeloma therapy. BPs continued at least until disease progression. PFS and OS were estimated using Kaplan-Meier methodology. Hazard ratios (HRs) were calculated using stratified Cox models. Adverse events (AEs) were monitored continuously and analyzed using cumulative incidence functions. Results: At a median follow-up of 5.8 y in 1960 evaluable pts, ZOL improved PFS (HR = 0.88; P = .01) and...