Loss-of-function variants were revealed in the ASXL1 and DNMT3A genes in 33% of patients in the group of resistant to therapy TKI, but not in other groups. 25% of patients in the treatment-resistant group had variants only in ASXL1, while 8% had variants in both ASXL1 and DNMT3A. The identified variants in ASXL1 and DNMT3A may be associated with resistance to TKI therapy and serve as prognostic markers of the TKI therapy effectiveness at the stage of CML diagnosis, and thus provide a personalized approach to the targeted CML therapy.