PS1185 FACTORS INFLUENCING PATIENT PREFERENCES FOR DISCONTINUATION OF TYROSINE KINASE INHIBITORS IN CHRONIC MYELOID LEUKEMIA

Abstract

Background:The tyrosine kinase inhibitors (TKI) are the initial treatment of choice for most patients with chronic myeloid leukemia (CML). The TKI is continued indefinitely as long as it is tolerated and the treatment milestones are met. Prospective trials are investigating whether TKI discontinuation is safe in patients who achieve sustained deep molecular response. We used an interview‐assisted survey of patients with CML at 9 hematology departments to explore patient preferences for stopping TKI treatment and identify variables associated with them.Aims:To identify factors influencing patient preferences for discontinuation of tyrosine kinase inhibitors in chronic myeloid leukemia.Methods:The study included patients with chronic phase CML currently being treated with a TKI and achieved at least major molecular response. The survey was conducted by a treating physician using a structured interview form with following parts: demographic and socioeconomic characteristics, course of the disease and its treatment, TKI compliance and side effects, questions about patient's consent to withdraw TKI according to risk of relapse and risk of TKI withdrawal syndrome, patient's arguments for and against discontinuation. 229 patients were evaluable. Median age was 61 (19–90). 50% were male. The demographic and socioeconomic characteristics were diversified. Median duration of TKI treatment was 8,2 years (0.6–16.4). 80% of patients were treated with imatinib in first‐line, 20% – with dasatinib and nilotinib.Results:The rate of patients who would discontinue TKI depended on CML relapse risk – from 11% in case of 80% relapse risk, to 90% in case of 10% relapse risk. 76% of patients expected to discontinue TKI taking into account the currently reported relapse risk (50%). After being informed about TKI withdrawal syndrome this rate decreased to 70%. Only 35% of patients justified their decision to stop TKI with side effects. The most common arguments against discontinuation were fear of molecular (47%) or clinical (45%) relapse. In multivariate analysis from all factors (demographic and socioeconomic characteristics, course of the disease and its treatment including depth of response, TKI compliance and side effects) only the attending physician (HR from 0.37 to 1.47 according to physician, p < 0,001) and TKI‐related muscle cramps (RR = 1.27, p < 0,001) were associated with patients’ will to discontinue TKI.Summary/Conclusion:70% of patients with chronic phase CML in MMR on TKI therapy would accept TKI discontinuation given the currently reported relapse and withdrawal syndrome rate. Patients are more likely to stop their TKI as the risk of relapse decreases and it doesn’t depend on compliance or occurrence of side effects. Patients report risk of relapse as the most important concern if they chose to stop their TKI. The attending physician and TKI‐related muscle cramps are associated with patients’ preference for stopping TKI therapy.