This retrospective chart review study investigated the clinical burden of adult patients with chronic-phase chronic myeloid leukemia (CP-CML) treated at three centers in France (2006–2021) who failed on two or more tyrosine kinase inhibitors (TKIs; third-line [3L]+ cohort) or harbored the BCR::ABL1 T315I mutation (T315I cohort). This evidence concerns the gene BCR and chronic myelogenous leukemia, BCR-ABL1 positive.