Early switch in tyrosine kinase inhibitor therapy for patients with chronic myeloid leukemia: An emerging clinical question.

Response to frontline BCR-ABL1-targeted tyrosine kinase inhibitor (TKI) therapy is associated with an improved prognosis for patients with chronic myeloid leukemia (CML). Accordingly, the National Comprehensive Cancer Network (NCCN) and European LeukemiaNet (ELN) recommend the use of specific response milestones (eg, BCR-ABL1≤10% on the International Scale at 3 months) to assess treatment success and inform follow-up care, including potentially switching to another TKI therapy. However, prior to any treatment change, the potential benefits and risks of each TKI and the goals of the patient must be considered. Here we review current NCCN and ELN response recommendations for patients with CML, highlight the impact of early responses on long-term prognosis, and discuss several reasons patients may consider a switch in TKI therapy. We also review completed and ongoing clinical studies involving a switch in frontline therapy for patients with CML, including those with a treatment-free remission phase.