Clinical management of second-generation tyrosine kinase inhibitor therapy in patients with newly diagnosed chronic myeloid leukemia in the chronic phase, focusing on age and dose effects.

ABL1-tyrosine kinase inhibitors (TKIs) are an established treatment choice for patients with chronic myeloid leukemia in the chronic phase (CML-CP). However, effects of TKI dose modification have not been well investigated. In this study, we retrospectively analyzed 178 patients with newly diagnosed CML-CP who were treated with dasatinib or nilotinib, focusing on age and dose effects. Efficacy as measured by cumulative major molecular response (MMR) and molecular response 4.5 rates did not differ significantly between the younger group and elderly group. Elderly patients who started nilotinib at a reduced dose had similar or better efficacy outcomes (including cumulative MMR and continuation ratios) than other groups, and elderly patients who started dasatinib at a reduced dose had the lowest MMR ratio and longest MMR duration. Effects of dose modification based on age and TKI selection can be attributed to flexible management of TKI therapy in real-world practice, but further studies are required to validate the findings of this study.