PB2142 BUSULFAN/CYCLOPHOSPHAMIDE (BU/CY) COMPARED WITH HIGH‐DOSE MELPHALAN (HDMEL) AS CONDITIONING REGIMEN FOR AUTO STEM CELL TRANSPLANTATION OF MULTIPLE MYELOMA

Abstract

Background:High dose melphalan (HDMEL) represents the standard conditioning regimen before auto stem cell transplantation (ASCT) for multiple myeloma (MM). But melphalan was inconvenient to obtain in mainland China.Aims:We compared two groups of MM patients who received HDMEL and busulfan/cyclophosphamide (BU/CY) regiment followed by ASCT.Methods105 patients newly diagnosed with MM in our center undergoing ASCT between May 2012 and August 2017 were enrolled. They were divided into two groups according to conditioning regimen (BU/CY vs. HDMEL). In BU/CY group, busulfan [0.6 mg/kg for those with creatinine clearance rate (CCR)≥60 ml/min and 0.5 mg/kg for CCR≥40 ml/min and <60 ml/min] was administered q6 h on days ‐7∼‐5 (7.2 mg/kg and 6.0 mg/kg in total, respectively) and cyclophosphamide (1.8 g/m2 for those CCR≥60 ml/min and 1.5 g/m2 for CCR≥40 ml/min and <60 ml/min) was given once on days ‐4∼‐3. In HDMEL group, melphalan (200 mg/m2) was given one dose on day ‐2.Results:At a median follow‐up of 30 months (range 0∼74 months), the average overall survival (OS) and median progression‐free survival (PFS) in BU/CY group were 53.7 months [95% confidence interval (CI) 49.3∼58.1] and 59.0 months (95% CI 48.3∼69.7) respectively, showing no significant difference with that of HDMEL group [average OS: 52.6 month (95% CI 44.5∼60.8) and median PFS: 8.0 months (95% CI 46.9∼69.1) respectively]. No significant difference was found in incidence of pneumonia, fever, mucositis, abnormal liver function, abnormal renal function between BU/CY group and melphalan group. No VOD was observed during the research.Summary/Conclusion:BU/CY conditioning regimen for MM before ASCT is not inferior to the HDMEL regimen in the Chinese mainland population. The regimen is effective and the toxicity can be tolerated.