Improved transplant outcomes in ALL with PTCy in the era of novel therapies

A retrospective cohort study compared outcomes in 214 patients with B-cell acute lymphoblastic leukemia (B-ALL) and 37 patients with T-cell ALL (T-ALL) who received post-transplantation cyclophosphamide (PTCy) across two eras: ERA1 (2008–2014) and ERA2 (2015–2022). Eligible patients underwent allogeneic blood or marrow transplantation (allo-BMT) with high-dose PTCy. Outcomes assessed included overall survival (OS), relapse-free survival (RFS), and cumulative incidence of relapse (CIR). Findings were published by Webster et al. in Haematologica. 

Key data: Despite patients in ERA2 being older (p = 0.03) with more comorbidities (p = 0.01), OS (hazard ratio [HR], 0.54; p = 0.005), RFS (HR 0.52; p = 0.001), and CIR (HR, 0.45; p = 0.0005) improved significantly compared with those in ERA1. Improvements were restricted to patients with B-ALL; improved RFS was observed in patients with B-ALL in first remission (CR1) who received pretransplant blinatumomab (HR, 0.40; p = 0.05) and those with Philadelphia chromosome-positive (Ph-positive) ALL in CR1 who received second- or third-generation tyrosine kinase inhibitor (TKI) vs imatinib (HR, 0.29; p = 0.0004).  

Key learning: The findings demonstrate improved allo-BMT outcomes in the era of more effective pretransplant therapies, driven by reductions in relapse, particularly in B-cell ALL. These improvements were most likely attributable to the introduction of novel agents, such as TKIs and blinatumomab.