Treatment Options for Chronic-Phase CML

Treatment options for chronic-phase chronic myeloid leukemia (CML) include:

The preferred initial treatment for patients with newly diagnosed chronic-phase CML could be any of the specific inhibitors of the BCR::ABL1 tyrosine kinase (including asciminib, nilotinib, dasatinib, bosutinib, or imatinib).[1] With any of these agents, the 10-year event-free survival and overall survival (OS) rates exceed 90%.[2-4]

CML response rate abbreviations used in this section include:

A BCR::ABL1 transcript level of 10% or less in patients after 3 months of treatment with a specific TKI (deemed EMR) is associated with the best prognosis in terms of failure-free survival, progression-free survival (PFS), and OS.[5-10] However, in a retrospective analysis, even patients with a BCR::ABL1 transcript level greater than 10% after 3 months of therapy did well when the halving time was less than 76 days.[11]

Mandating a change of therapy based on this 10% transcript level at 3 to 6 months is problematic because 75% of patients do well even with a suboptimal response.[12] After 1 year, the preferred response target is an MMR, which is defined as a BCR::ABL1 level of less than or equal to 0.1%. The optimal target is a DMR, which is defined as under 4 logs (BCR::ABL1 ≤ 0.01%) or undetectable, which is usually a BCR::ABL1 level of less than or equal to 0.001% (MR 5).[13]