Treatment with asciminib after a prior tyrosine kinase inhibitor in patients with chronic-phase chronic myeloid leukemia

Abstract

Background: In chronic-phase chronic myeloid leukemia (CML-CP), switching tyrosine kinase inhibitor (TKI) therapy due to intolerance or resistance is common. While asciminib, an ABL/BCR::ABL1 TKI targeting the ABL myristoyl pocket, offers improved tolerability and efficacy, there is limited real-world effectiveness data, particularly among patients with treatment with one prior TKI.

Patients and methods: A retrospective, US physician panel-based chart review study was conducted on adult patients with CML-CP without T315I treated with asciminib after one prior TKI. Time-on-treatment, and time-to achieving or maintaining MR2 (BCR::ABL1 ≤ 1 %), MMR (BCR::ABL1 ≤ 0.1 %) and DMR (BCR::ABL1 ≤ 0.01 %) were assessed using Kaplan-Meier analyses. Subgroup analyses were performed among patients with first TKI discontinuation due to intolerance or resistance, and by first- or second-generation TKI as first TKI.

Results: Overall, 255 patients (median age 62 years, 56.5 % male) were included. Imatinib (49.8 %), dasatinib (34.5 %), nilotinib (10.6 %), and bosutinib (5.1 %) were received as first TKI. Intolerance and resistance to first TKIs were reported for 43.5 % and 23.5 % of patients, respectively. At 48-weeks post-asciminib initiation, 95.0 % of patients (95 % CI: 91.3 %, 97.1 %) remained on asciminib, 84.0 % (95 % CI: 78.6 %, 88.6 %) achieved or maintained MR2, 68.3 % (95 % CI: 61.8 %, 74.5 %) MMR, and 40.6 % (95 % CI: 34.2 %, 47.8 %) DMR.

Conclusions: Overall, most patients remained on treatment and achieved or maintained MMR, suggesting that asciminib was well-tolerated and effective. Results were consistent among subgroups, indicating that asciminib is an effective option for patients regardless of prior TKI used, and including those intolerant or resistant to their first TKI.

Micro-abstract: There is limited real-world data regarding the effectiveness of asciminib after one prior tyrosine kinase inhibitor (TKI) in chronic-phase chronic myeloid leukemia (CML-CP). In this US physician panel-based chart review, nearly all patients (95 %) remained on asciminib and 68 % achieved or maintained a major molecular response at 48 weeks, suggesting that asciminib is well-tolerated and effective after one prior TKI.

Keywords: BCR::ABL1; Hematological malignancies; Molecular response; Real-world evidence.