INTERMEDIATE-DOSE MELPHALAN (IDM) COMBINED WITH G-CSF (FILGRASTIM) ISAN EFFECTIVE AND SAFE INDUCTION THERAPY FOR AUTOLOGOUS STEM-CELL, TRANSPLANTATION IN MULTIPLE-MYELOMA

Twenty-one previously untreated multiple myeloma (MM) patients and 10 previously treated patients with refractory or relapsed disease receiv ed two or three cycles of intermediate-dose melphalan (70mg/m(2)) (IDM ), administered intravenously every 6 weeks. Seven previously untreate d patients received three and all other patients received two courses of TDM. The objective of the study was to reduce the toxicity of high- dose melphalan (140 mg/m(2)) (HDM) while maintaining its cytotoxic eff icacy and secondly to ensure the possibility of collecting sufficient numbers of peripheral blood stem cells (PBSC) for transplantation. 18 (85%) previously untreated patients responded, of whom four achieved C R (18%). In addition five out of 10 previously treated patients with r efractory or relapsed disease responded although bone marrow toxicity in this category was a major drawback. Toxicity was moderate, consisti ng of alopecia acid moderate bone marrow suppression: the granulocyte count dropped below 0.5 x 10(9)/l and platelets below 25 x 10(9)/l for a median of 8 and 6 d, respectively. No serious infections occurred a nd the majority of patients attended the out-patient clinic. In 12/14 previously untreated patients sufficient peripheral blood CD34(+) cell s for harvest were present in the repopulation phase after the first I DM. In nine patients peripheral blood stein cells were collected and e ight patients have undergone succesful transplantation. Repeated IDM f ollowed by filgrastim is highly effective in untreated MM and may be s afely administered to reduce tumour load prior to PBSC collection, Aut ologous stem cells harvested after repeated IM have a full long-term r epopulating capacity.