Real-world data on the use of asciminib in chronic-phase chronic myeloid leukemia after two or more prior tyrosine kinase inhibitors: Results of the Turkish managed access program along with a literature review.

Asciminib is a first-in-class STAMP inhibitor used in treating patients with chronic-phase chronic myeloid leukemia (CML-CP). Although its efficacy has been demonstrated in clinical trials, real-world data remain limited, particularly in heavily pretreated populations. This multicenter, retrospective study included patients with CML-CP from 25 centers in Turkey who received asciminib through a Managed Access Program. All patients had received at least two prior tyrosine kinase inhibitors (TKIs) or harbored the T315I mutation. Early molecular response (EMR), major molecular response (MMR), and deep molecular response (DMR) were evaluated according to the ELN 2020 criteria. There were 49 patients with a median age of 61 years. Patients had a median of 4 prior TKIs, and resistance was the most common reason for switching (47%). Seven patients (14.2%) carried the T315I mutation. EMR at 3 months was achieved in 80% of evaluable patients, higher among those switched due to intolerance than to resistance (90% vs. 74%), and higher among ponatinib-pretreated than ponatinib-naïve patients (94% vs. 72%). Cumulative MMR and DMR rates were 32.6% and 37.2%, respectively. Higher response rates were observed in patients switched due to toxicities and in those previously treated with ponatinib. Among patients with the T315I mutation, 71.4% maintained or improved their response. Three patients died during follow-up. Asciminib 40 mg BID and 80 mg QD regimens seemed to be comparable regarding both efficacy and safety. In this real-world cohort, asciminib was well tolerated and provided meaningful responses in heavily pretreated CML-CP patients, consistent with the published data. Favorable outcomes in ponatinib-pretreated patients may partly reflect prior achievement of optimal response before switching due to limited access.