Tyrosine kinase inhibitor therapy discontinuation in patients with chronic myeloid leukemia in chronic phase in the United States after clinical practice guideline updates

A physician survey (July 2019-August 2019) and a retrospective patient medical chart review (November 2019-December 2019) were conducted to assess TKI therapy discontinuation practice in patients with Ph + CML-CP in the US after the publication of practice guidelines updated with recommendations for TKI discontinuation. After guideline updates, 90% of physicians from the survey reported attempting TKI discontinuation and 24% of their patients discontinued TKI after achieving an adequate response. Although TKI therapy discontinuation practice is increasing, particularly in community-based practice, a little more than half of physicians were aware of these updated guidelines resulting in TKI discontinuation attempted under suboptimal conditions, mainly limited to first-line TKI therapy, with more than half of physicians without access to at least MR4.5 sensitivity level of detection monitoring. Stricter response criteria per guideline recommendations were observed to relate to lower relapse rates following TKI discontinuation, emphasizing the importance of communicating these recommendations and access to adequate monitoring tools.