Tyrosine kinase inhibitor therapy treatment and discontinuation in patients with chronic myeloid leukemia in chronic phase in the United States: a clinical practice perspective

Tyrosine kinase inhibitor (TKI) therapy discontinuation practice in patients with chronic myeloid leukemia chronic phase (CML-CP) was assessed in real-world practice prior to the release of recommendations on discontinuation. Data were collected from US oncologists/hematologists (through web-based physician survey and patient chart review) on TKI therapy discontinuation practice including monitoring, adequate response for discontinuation, relapse, and symptoms following discontinuation. From the physician survey, 34% of oncologists/hematologists attempted discontinuation, with two-thirds doing so outside of a trial. From the chart review, TKI therapy was discontinued in 3.4% of patients after they achieved an adequate response with the intention to remain CML-therapy-free until disease relapse. Among these patients, 21% relapsed and 17% had symptoms following discontinuation. There was a lack of consensus on the definition of adequate response suggesting that discontinuation was attempted without clear guidelines and under suboptimal conditions underscoring the need for physician education regarding guidelines for TKI therapy discontinuation.