Very long‐term outcomes of chronic‐phase chronic myeloid leukaemia patients treated with imatinib: A 25‐year real‐world cohort study

Imatinib has revolutionized the management of chronic-phase chronic myeloid leukaemia (CP-CML). This study aimed to evaluate the long-term efficacy, safety and prognostic determinants of imatinib in a large cohort of CP-CML patients in real-life clinical practice. We conducted a retrospective, monocentric observational study including all adult patients with CP-CML treated with imatinib between 2000 and 2025. Overall survival (OS), event-free survival (EFS) and progression-free survival (PFS) were estimated using Kaplan-Meier analysis. A total of 210 patients were included, of whom 81% received imatinib as first-line therapy. The median follow-up was 12.4 years. At 25 years, OS and PFS were 71% and 88% respectively. The EUTOS long-term survival (ELTS) score independently predicted OS, EFS and PFS (p < 0.001), while lower risk categories were associated with a faster achievement of major molecular response (MMR) and a higher probability of deep molecular response (DMR). Dose reductions were applied in 26.2% of patients, mainly older individuals with higher Charlson comorbidity index (CCI), without affecting molecular or survival outcomes. Higher CCI values correlated with inferior OS. The ELTS score remains a powerful prognostic tool for long-term outcomes. No unexpected safety concerns were observed in the long term. Over 25 years of real-world experience, imatinib has demonstrated sustained efficacy, safety and tolerability in CP-CML.