This retrospective chart review had the purpose of reviewing the experience of chronic myeloid leukemia (CML) patients who stopped their tyrosine kinase inhibitor (TKI) treatment off clinical trial, in hopes of obtaining treatment-free remission (TFR). The outcome of cessation of therapy for 9 chronic-phase CML patients who stopped their TKI treatment for various reasons is presented. The total duration of TKI of treatment before the stopping trial had a median of 102 months (range 64-193). Among all patients, 7 (78%) were considered successful and 2 (22%) were considered not successful in remaining in TFR. Patients were tested either every 6 or 12 weeks after stopping treatment to monitor for a loss of major molecular response (MMR) as an endpoint for determining reoccurrence.

With this patient experience data, we hope to pave the way for a prospective trial that can give evidence for a new clinical paradigm that would be helpful in the real world with every 6-week testing and using MR4.0 as the necessary depth of remission. These laboratory criteria and requirements accessible in all Ontario facilities, and other facilities with similar limitations, are essential for these new guidelines.