Allogeneic transplantation outcomes in chronic myeloid leukemia in the era of tyrosine kinase inhibitors.

BACKGROUND: Allogeneic hematopoietic cell transplantation (allo-HCT) remains relevant for selected patients with chronic myeloid leukemia (CML) in the tyrosine kinase inhibitor (TKI) era. METHODS: We retrospectively evaluated consecutive adults initially diagnosed with chronic-phase CML who underwent first allo-HCT in Argentina between 2010 and 2023 after receiving at least one TKI. All were in first or second chronic phase at transplantation. RESULTS: Eighty patients were included; median age was 41.7 years, 53.7% had prior blast phase (BP), and 67.5% received HLA-matched grafts. Among 71 evaluable patients, 43.7% had no pretransplant molecular response (MR). After a median follow-up of 58.4 months, 5-year overall survival (OS) and progression-free survival were 52.1% and 47.7%. OS was lower with prior BP than without prior BP (35.4% vs. 73.1%; p < 0.001) and without pretransplant MR than with any MR (38.5% vs. 59.4%; p = 0.022). Prior BP, absence of MR, and HLA mismatch were independently associated with inferior OS. Among patients with prior BP, post-transplant TKI maintenance was associated with higher OS. The 1-year non-relapse mortality and relapse rates were 17.7% and 20.1%, respectively. CONCLUSION: Allo-HCT provides durable disease control in selected patients with CML. The find potential survival benefit of maintenance therapy requires prospective validation.