Non-myeloablative allogeneic peripheral stem cell transplantation for multiple myeloma.

OBJECTIVE To present an institution's 2-year experience of non-myeloablative allogeneic stem cell transplantation among Chinese patients. DESIGN Retrospective study. SETTING Bone marrow transplantation unit at a university hospital, Hong Kong. PATIENTS Ten patients with multiple myeloma who received non-myeloablative allogeneic stem cell transplantation between March 2000 and October 2002. INTERVENTION Fludarabine (90 mg/m(2)) and total body irradiation (300 cGy) were given as conditioning regimens, followed by non-myeloablative allogeneic stem cell transplantation. MAIN OUTCOME MEASURES Engraftment, regimen-related toxicity, treatment-related mortality (in the first 100 days), incidence of graft-versus-host disease, chimerism, disease response, and survival rate. RESULTS All 10 patients had active disease before transplantation. The donors were eight human leukocyte antigen-matched siblings, a mismatched sibling, and a matched daughter. Satisfactory engraftment before day 21 was achieved without early treatment-related mortality. Five patients developed full donor chimerism by day 28 and three other patients had 100% donor chimerism by day 100. Acute graft-versus-host disease developed in six patients (five with grade III and one with grade IV disease), and chronic graft-versus-host disease developed in eight patients (four with extensive disease). Complete remission and partial response were achieved in three and four patients, respectively. Three patients did not respond to treatment, and one case of relapse was observed. Only one patient, who had shown a partial response, received donor lymphocyte infusion; seven patients received thalidomide for graft-versus-host disease with or without graft-versus-myeloma effect. All patients were alive after a median follow-up of 1 year. CONCLUSION Non-myeloablative allogeneic stem cell transplantation for multiple myeloma is effective, has low toxicity, and results in low treatment-related mortality. Studies of more cases with longer follow-up durations are required.