Dose Modifications in the Management of Chronic Phase Chronic Myeloid Leukemia: Who, What, and When

With the availability of BCR::ABL1 targeted tyrosine kinase inhibitors (TKIs), outcomes for most individuals with chronic phase chronic myeloid leukemia (CP-CML) are outstanding, with life expectancy similar to age-matched peers. Treatment-emergent adverse events (TEAEs) impair quality of life and many patients struggle with low-level chronic AEs, which for some individuals impact emotional well-being as well as social and work functioning. An emerging body of data supports that many TEAEs are related to therapy dose and can improve with dose reduction. However, it is critical that dose reductions do not alter current outcomes, especially in the rare patients who are at greater risk of losing response or transforming to acute leukemia. Organizations including the National Comprehensive Cancer Network have begun to address when dose reductions may be considered in patients with CP-CML. In this manuscript, we review retrospective and prospective data reporting outcomes in patients after dose reduction and review data supporting lower dose preemptive dosing in first-line and later-line therapy. Switching therapy for intolerance can result in improvements in symptoms and limit toxicity, but other TEAEs may occur. Additionally, emerging therapeutics such as the new class of BCR::ABL1 allosteric inhibitors are under evaluation with a goal of improving tolerability. However, with many TKIs on the cusp of becoming generic, dose reduction becomes an appealing and important cost-effective strategy to minimize TEAEs and improve quality of life while preserving outstanding outcomes in CP-CML.