REFRACTORY AND RELAPSING MULTIPLE-MYELOMA TREATED BY BLOOD STEM-CELL TRANSPLANTATION

Between June 1989 and June 1992, 12 patients with advanced multiple my eloma underwent peripheral blood stem cell autotransplantation after h igh-dose chemotherapy and radiotherapy. The conditioning regimen inclu ded melphalan (140 mg/m(2)), high-dose cyclophosphamide (120 mg/kg), m ethylprednisolone (2 g daily X 7), and total body irradiation (9-12 Gy ). Transplant morbidity included severe mucositis (n = 7) and acute re nal failure (n = 2) related to infusion of the stem cells. Engraftment was delayed (n = 4) in this heavily pretreated population, and two pa tients had complete graft failure. Despite the advanced nature and che motherapy-refractory state of their disease, 11 of 11 evaluable patien ts achieved an objective response. Six patients survived to leave the hospital, and four remain alive-one died of acute leukemia induced by prior melphalan exposure. Three of the four are relapse-free at a medi an of 24.9 months (range, 18-28 months). Some patients with advanced r efractory multiple myeloma can achieve objective responses from high-d ose chemoradiotherapy with peripheral blood stem cell rescue. Harvesti ng peripheral blood stem cells from high-risk patients early in their disease for later use may decrease the risk of graft failure. Peripher al blood stem cell transplantation after high-dose chemotherapy and to tal body irradiation can produce durable responses in patients with ad vanced refractory myeloma.