[Application of Conditioning Regimen with Busulfan and Cyclophosphamide in Autologous Hematopoietic Stem Cell Transplantation in Multiple Myeloma].

Objective: To evaluate the safety and efficacy of BUCY (busulfan and cyclophosphamide) conditioning regimen for autologous hematopoietic stem cell transplantation (ASCT) in patients with multiple myeloma (MM).

Methods: The clinical data of 72 MM patients received transplantation in the Hematology Department of the First Affiliated Hospital of Soochow University from May 2012 to June 2015 were retrospectively analyzed. Among them, 36 patients received BUCY conditioning regimen while the others received high-dose melphalan (HDM) conditioning regimen. The complication, post-transplantation hematopoietic reconstitution and efficacy between the two groups were compared.

Results: There were no significant differences in sex, age, isotype, stage, induction therapy, mobilization method and proportion of conditioning regimen with Bortezomib between the two groups. The median time of neutrophil engraftment for the patients in BUCY and HDM groups was 10 (8-17) and 10 (9-13) d (P=0.046), and the median time of platelet engraftment was 10 (8-18) and 11 (9-47) d (P=0.017), respectively. The transplant related mortality of the patients in both groups was 2.7%. The CR rates of the patients after ASCT (38.9% and 50.0%) were higher than those before ASCT (27.8% and 19.4%) in the two groups. For the patients in BUCY group, the median follow-up time was 45 (0-61) months. Fifteen patients (41.7%) achieved disease progression. While for the patients in HDM group, the median follow-up time was 52(0-75) months. Twenty-two patients (61.1%) achieved disease progression.

Conclusion: The BUCY conditioning regimen is a safe and effective therapy for ASCT in patients with MM. Besides, in terms of safety and efficacy, BUCY regimen is not inferior to HDM regimen. BUCY regimen may replace HDM regimen as a standard conditioning regimen for ASCT in MM.