ASC4OPT: asciminib treatment optimization study in patients with chronic myeloid leukemia in chronic phase previously treated with two or more tyrosine kinase inhibitors.

The ASC4OPT non-comparative phase 3b study (NCT04948333) evaluates asciminib once daily (QD) or twice daily (BID) in chronic myeloid leukemia in chronic phase (CML-CP) treated with ≥2 tyrosine kinase inhibitors (TKIs). This study enrolled 169 patients not in major molecular response (MMR), with unsatisfactory response (intolerant, warning or failure) as defined by European LeukemiaNet (ELN) 2020 criteria. Patients intolerant to their most recent TKI and in MMR at baseline (n = 30) were also enrolled. The primary endpoint was the MMR rate at Week 48 for patients not in MMR at baseline. Results showed an overall MMR rate of 39.4% at Week 48 (40 mg BID, 43.4%; 80 mg QD, 35.4%) and 43.6% at Week 96 (40 mg BID, 45.8%; 80 mg QD, 41.5%) in patients not in MMR at baseline. Among 40 patients who had their asciminib dose escalated to 200 mg QD, 17.5% were in MMR at Week 96. Most patients in MMR at baseline remained in MMR at 48 and 96 weeks (93.3% and 86.7%, respectively). Safety for both dosing regimens was consistent with that of previous studies. Findings support asciminib as a potential standard of care for patients with CML-CP who have not responded optimally to prior TKI therapy.