First-line treatment outcomes of CML patients in a real-world data setting in Lebanon.

Abstract

e19031 Background: BCR–ABL-targeting tyrosine kinase inhibitors (TKIs) constitute the cornerstone of treatment of CML leading to a life expectancy that is currently very close to that of age matched individuals in the general population. The aim of the current study was to describe aspects of CML in a real world data setting in Lebanon including responses to first lines with a specific focus on the impact of first-line treatment with imatinib compared to that of the second-generation TKI, dasatinib and nilotinib. We also evaluated what proportion of patients become eligible to attempt to stop their TKI treatment. Methods: Chronic myeloid leukemia registry was analyzed to evaluate response rates in the first line and eligibility for a treatment cessation attempt in adults diagnosed between 2003 and 2019. The registry covered 60 patients. 46 eligible patients were included in the study. BCR-ABL1 levels of ≤ 0.1%, ≤0.01% and ≤0.0032% on the international scale were defined as the molecular response end-points major molecular response(MMR), MR4.0 and MR,4.5 respectively. In the case of a switch in TKI therapy, the clinical chart was reviewed for the reason why the treating physician had changed the therapy (‘treatment failure’ or ‘TKI intolerance’). For the determination of eligibility to stop TKI, the inclusion criteria for the EURO-SKI trial were applied. Results: Seventy-two percent of the patients were treated with imatinib, 28% with a second-generation tyrosine kinase inhibitor (nilotinib and dasatinib). 15% of patients had discontinued their first-line treatment, mainly due to intolerance (10%) or treatment failure (5%). At 24 months, deep molecular response (MR 4.0 and MR4.5) were achieved at 16.7% and 38.9% respectively for imatinib, and at 22.2% and 33.3% respectively for second generation (p=1). The 5-year cumulative incidence of eligibility for a tyrosine kinase cessation attempt, according to EURO-SKI criteria, was 37%. Conclusions: In the current study we report the experience in CML from two health care institutions in Beirut, Lebanon. Our findings showed no statistically significant difference in response between the first and second generations. The criteria for an attempt to stop tyrosine kinase inhibitor therapy are met by a third of the patients.