BU and CY as conditioning regimen for autologous transplant in patients with multiple myeloma

High-dose melphalan is considered the current standard of care among the preparative regimens used in peripheral blood autologous SCT (ASCT) for multiple myeloma (MM). We report the results of a single ASCT in 79 MM patients using the BU/CY conditioning regimen, with BU 1mg/kg p.o. or 0.8mg/kg i.v. every 6h × 16 doses, and CY 60mg/kg per day i.v. for 2 days. ASCT was carried out in first (62%) or subsequent remission/ refractory disease (38%). For an overall RR of 86%, 48 and 20 patients achieved PR and CR, respectively. At a median follow-up of 41 months (range 2-132 months), the estimated median OS and PFS were 45 months (95% confidence interval (CI) = 38-92) and 20 months (95% CI = 15-25), respectively. The BU/CY regimen was well tolerated, and transplant-related mortality was 4%. Clinical outcomes of the BU/CY regimen are not superior to those obtained in historical controls with high-dose melphalan followed by a single ASCT. Therefore, considering even the greater complexity of administration of the BU/CY regimen compared with that of single-agent melphalan, we believe the latter should remain the conditioning regimen of choice for ASCT in MM.