Weekly Cyclophosphamide and Alternate-Day Prednisone: An Effective, Convenient, and Well-Tolerated Oral Treatment for Relapsed Multiple Myeloma After Autologous Stem Cell Transplantation

OBJECTIVE: To assess the efficacy and tolerability of weekly oral cyclophosphamide in combination with alternate-day prednisone (CP) as salvage therapy for patients with relapsed multiple myeloma (MM) after autologous stem cell transplantation (ASCT). PATIENTS AND METHODS: We retrospectively reviewed the medical records of all patients identified in our clinical database as having received CP as treatment for relapsed MM after ASCT at Princess Margaret Hospital between July 1998 and May 2004. The CP regimen consisted of oral cyclophosphamide at 500 mg once weekly and oral prednisone at 100 mg on alternate days. RESULTS: A total of 66 patients received the CP regimen, with a median of 2.0 prior therapies (range, 1.0-5.0) from time of diagnosis to initiation of CP. The median time from relapse after ASCT to start of CP therapy was 1.5 months (range, 0.0-23.5 months). Because of nonsecretory disease in 7 patients, only 59 patients were evaluable for response. The median duration of CP treatment was estimated at 5.8 months (95% confidence interval [CI], 4.6-7.8 months). With a median follow-up of 15.9 months (range, 1.4-67.2 months), 36 patients (61%) responded to treatment, 24 (41%) of whom had a partial response. The 1-year progression-free survival of all evaluable patients was estimated at 66% (95% CI, 54%-80%), with a median progression-free survival of 18.6 months (95% CI, 13.9-29.9 months). The median overall survival from time of initiation of CP was estimated at 28.6 months (95% CI, 22.1-not available months). CONCLUSION: Our data show that CP is an effective, well-tolerated, and convenient regimen as salvage therapy for MM after ASCT.