Direct measurement of in vivo BCR::ABL1 kinase inhibition reveals stronger potency of asciminib as compared with imatinib and nilotinib.

Asciminib is the first approved BCR::ABL1 inhibitor that Specifically Targets the ABL Myristoyl Pocket (STAMP) [ 1 , 2 ]. In ASC4FIRST, with longer follow-up, asciminib continued to demonstrate a favourable benefit-risk profile over investigator-selected (IS)-tyrosine kinase inhibitors (TKIs) and imatinib [ 3 ]. Its specificity minimizes off-target toxicity [ 1 , 2 , 3 , 4 , 5 ]. The degree of BCR::ABL1 inhibition achieved in patients receiving asciminib compared to 2 nd generation TKI (2G-TKI), has not been assessed.