Long-term follow-up of an intensified myeloablative conditioning regimen with in vivo T cell depletion followed by allografting in patients with advanced multiple myeloma

Abstract

We report long-term results after a median follow-up of 105 months in 18 patients with multiple myeloma who received an intensified myeloablative conditioning regimen regimen consisting of modified total body irradiation, busulfan, cyclophosphamide, and antithymocyte globulin, followed by allogeneic stem cell transplantation (SCT). Grade II-IV acute graft-versus-host disease occurred in 7 patients (44%), and treatment-related mortality was 17%. Complete remission (CR) with negative immunofixation after allogeneic SCT occurred in 53% of the patients. For all patients, the estimated overall survival at 12 years was 50% (95% confidence interval [CI], 26%-74%), and the estimated event-free survival (EFS) was 35% (95% CI, 23%-57%). Those patients who achieved CR after SCT had a 12-year estimated PFS of 60%, whereas none of the patients without CR remained progression-free. Our data indicate that an intensified myeloablative conditioning regimen followed by allogeneic SCT can produce long-term survival and freedom from disease in patients with multiple myeloma who achieve CR.