Treatment patterns and outcomes of tyrosine kinase inhibitors in chronic myeloid leukemia: a single center study from Oman.

BACKGROUND

Real-world data on tyrosine kinase inhibitor (TKI) use in chronic myeloid leukemia (CML) from the Middle East remain limited. We evaluated treatment patterns, molecular responses, treatment-free remission (TFR), and safety among Omani patients with chronic-phase CML.

METHODS

In this retrospective single-center study, adult patients (≥18 years) with chronic-phase CML treated with TKIs between January 2008 and September 2024 were included. Demographics, Sokal risk, treatment lines, molecular responses, TFR, and adverse drug reactions (ADRs) were analyzed.

RESULTS

Among 112 patients (mean age 43.7 ± 15.4 years), 45% had low Sokal risk, 43% intermediate, and 12% high risk. Imatinib was first-line therapy in 88.4%, achieving major molecular response (MMR) in 51%, with a median time to MMR of 21 months. In contrast, second-line TKIs demonstrated higher efficacy, with MMR rates of 79.2% for nilotinib and 54.4% for dasatinib, and shorter time to response (12 vs 23.2 months, respectively). Successful TFR was maintained in 17% of imatinib-treated patients after two years and in 83.3% of second-line patients after 36 months. ADRs were mainly gastrointestinal (28.5%), musculoskeletal (28.0%), dermatologic (20.8%), and hematologic (8.7%). Grade 3-4 events occurred in 5%, leading to TKI switching. Discontinuations were primarily due to loss of response, ADRs, or planned TFR.

CONCLUSION

In this real-world cohort, first-line imatinib provided acceptable but slower and less frequent molecular responses compared with second-generation TKIs. Higher TFR maintenance rates were observed with second-generation TKIs, although interpretation is limited by small patient numbers. These findings support a response-guided, risk-adapted approach to TKI selection and highlight the need to expand access to second-generation TKIs to optimize long-term outcomes in CML.