OBJECTIVETo evaluate the efficacy and safety of dose-reduced intravenous busulfan, cyclophosphamide and etoposide (BCV) as conditioning for autologous stem cell transplantation (ASCT) in multiple myeloma (MM).

METHODSFrom September 2007 to September 2010, thirty-two ASCT-eligible patients with MM received high dose melphalan (HDM) as conditioning in our center. Median age was 53.5 (30-63) years. From October 2010 to October 2012, thirty-eight patients conditioned by BCV regimen (intravenous busulfan, total doses 9.6 mg/kg), whose median age was 54(35-64) years.

RESULTSThere were no statistical differences in clinical characteristics between the two groups, including myeloma isotype, Durie-Salmon staging, international staging system(ISS), and patients received the first line, second line or more than third line therapy. The median time to neutrophil and platelet engraftment were 10.5 vs 11 days (P=0.057) and 11 vs 12 days (P=0.100) in the BCV and HDM groups, respectively. The toxicity of two conditioning regimens had no significant difference. None of hepatic veno-occlusive disease and early transplant related mortality was observed. Although overall response rates showed no significant difference between two groups (P>0.05), the CR rates increased from 44.74% pre-ASCT to 63.18% post-ASCT in the BCV group, while 37.50% to 59.38% in the HDM group. During the median follow-up of 16 months (range 2-27) in BCV group, ten patients (26.32%) developed progressive disease and PFS at 12 months were 71.37%.

CONCLUSIONSIn this study, the dose-reduced intravenous busulfan, cyclophosphamide and etoposide (BCV) conditioning was demonstrated an effective and safety regimen for ASCT-eligible patients with MM. However, the long term observation is needed.