A retrospective study based in Sweden showed that discontinuation of tyrosine kinase inhibitor (TKI) therapy in patients with chronic myeloid leukemia (CML) occurs regularly in population-based settings and can be done successfully. The study’s results were published in the British Journal of Haematology.
The study was based on data from the Swedish CML registry involving 584 patients who had chronic-phase CML, with the diagnosis received between January 2007 and December 2012. A total of 548 patients were evaluable for analysis of TKI discontinuation.
The median follow-up was 8.9 years after diagnosis, and nearly one-quarter (23%) of patients had discontinued TKI treatment for at least 1 month as a result of achieving deep molecular response (DMR). Another 20% of patients had discontinued TKI therapy for at least 1 month for other reasons, such as adverse events (18.7%) or allogeneic stem cell transplantation (13.6%).
With patients who stopped TKI therapy in DMR, the median time between diagnosis and TKI discontinuation was 5.3 years. Approximately half (49.2%) of the patients who stopped TKI therapy while in DMR restarted TKI therapy, with a median time from discontinuation to restart of 4.8 months. Among patients who had discontinued TKI therapy while in DMR, there was a 47.8% probability of restarting TKI therapy at 12 months.
In the cohort of patients who discontinued while in DMR, TKI discontinuation occurred in the setting of a clinical trial for 29.7% of patients, while 70.3% of discontinuations occurred outside of a clinical trial. At 2 years, patients who discontinued in DMR while in the setting of a clinical trial had restarted TKI therapy with a probability of 73.7%, and for those outside of a clinical trial this rate was 41.4%.
“In summary, our results from a population-based study show that TKI discontinuation in CML in clinical practice is common and feasible and as successful as when performed within a clinical trial,” the study investigators concluded in their report.
Flygt H, Sandin F, Dahlén T, et al. Successful tyrosine kinase inhibitor discontinuation outside clinical trials — data from the population-based Swedish chronic myeloid leukaemia registry. Br J Haematol. 2021;193(5):915-921. doi:10.1111/bjh.17392