Reduced‐intensity conditioning with fludarabine/busulfan versus fludarabine/low‐dose melphalan in patients with non‐Hodgkin lymphoma undergoing allogeneic haematopoietic stem cell transplantation

Abstract

SummaryReduced‐intensity conditioning regimens are commonly used in allogeneic haematopoietic cell transplantation for non‐Hodgkin lymphoma (NHL); however, the optimal regimen remains unknown. In this study, the outcomes of adult patients with NHL who received fludarabine plus reduced‐dose busulfan (6.4 mg/kg; Flu/Bu2) (n = 286) and fludarabine plus low‐dose melphalan (80 or 100 mg/m2; Flu/Mel80–100) (n = 283) between January 2009 and December 2020 were compared using Japanese registry data. The primary end‐point was the 5‐year overall survival (OS). The 5‐year OS was 53.8% (95% CI, 47.6–59.6) and 42.4% (95% CI, 35.6–49.0) in the Flu/Bu2 and Flu/Mel80–100 groups respectively (p = 0.030). After inverse probability of treatment weighting adjustment, the adjusted HR of Flu/Bu2 compared with Flu/Mel80–100 group for 5‐year OS was 0.77 (95% CI, 0.60–0.99, p = 0.046), 0.97 (95% CI, 0.78–1.21, p = 0.798) for 5‐year progression‐free survival, 0.65 (95% CI, 0.45–0.94, p = 0.022) for 5‐year cumulative risk of non‐relapse mortality and 1.25 (95% CI, 0.95–1.64, p = 0.115) for 5‐year cumulative risk of relapse. In this study, patients with NHL who received Flu/Bu2 were associated with better OS and lower non‐relapse mortality than those who received Flu/Mel80–100.