Improvements over time in survival after post‐transplant relapse of adult T‐cell leukaemia/lymphoma and trends of salvage therapy in a real‐world experience

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) offers potentially curative outcomes for adult T-cell leukaemia/lymphoma (ATL), but post-transplant refractory/relapsed (R/R) ATL is associated with poor outcomes. Advances have been made in transplant modalities, novel targeted agents and supportive care; however, it remains unclear whether these advances have improved survival outcomes of post-transplant R/R ATL. To clarify changes in survival after post-transplant R/R, we evaluated the survival outcomes in 1146 patients over a 24-year period, using a nationwide database. The period was divided into three groups: 1999-2010 (early period, as reference), 2011-2016 (middle period) and 2017-2022 (late period). In patients with refractory ATL, multivariate analyses showed no significant difference in overall mortality (OM) after post-transplant refractory in the early and middle periods, but a significantly lower OM in the late period than in the early period (hazard ratio [HR], 0.73 [95% confidence interval, 0.55-0.96]). In patients with relapsed ATL, OM after post-transplant relapse was significantly lower in the middle (HR 0.62 [0.48-0.80]) and late periods (HR 0.68 [0.52-0.90]) than in the early period. Thus, recent advances appear to have contributed to increased opportunities for therapeutic interventions, leading to improved survival outcomes in patients with post-transplant R/R ATL.