TKI resistance is a critical event in the treatment of Chronic Phase-Chronic Myeloid Leukemia¹

*Data are from the Ibrahim et al [N=26], Garg et al [N=48], and Garcia-Gutierrez et al [N=105] publications. Ibrahim et al analyzed a cohort of patients with CP-CML who failed dasatinib (n=20) or nilotinib (n=6) after imatinib in various phase 2 studies; none of the 7 patients with prior hematologic resistance to TKI therapy achieved CCyR. Garg et al analyzed CML patients (AP, BP, and CP) sequentially treated with 3 different TKIs at MD Anderson Cancer Center; 34 received dasatinib after imatinib and nilotinib failure, and 14 received nilotinib after imatinib and dasatinib failure. Among 25 patients with CP-CML receiving 3L therapy, only 2 of 17 who had failed 2L due to resistance achieved CCyR in 3L. Garcia-Gutierrez et al identified 105 patients treated with a 2G TKI in 2L after imatinib failure in a Spanish national registry; 17 of 31 patients who started 3L therapy with another TKI did so due to resistance, and the cumulative incidence of CCyR among these patients was 18%.^2-4

^†Based on nonrandomized, observational, retrospective studies that may have unobserved confounding and treatment selection biases as well as other limitations that should be considered when comparing results with clinical trials. Outcomes should be interpreted with caution due to small sample size.  

^‡Data are from clinical trials of 2L bosutinib [N=46; N=288], nilotinib [N=321], and dasatinib [N=150] in patients with CP-CML who were resistant or intolerant to prior TKI therapy.

2G=second generation; 2L=second line; 3L=third line; AP=accelerated phase; BP=blast phase; CCyR=complete cytogenetic response; CHR=complete hematologic response; CML=chronic myeloid leukemia; CP=chronic phase; CP-CML=chronic-phase chronic myeloid leukemia; TKI=tyrosine kinase inhibitor.

^aResults are primarily from a 3L study with 2G TKI therapy, but also included 3 patients taking 4L 2G TKI therapy.
^bApproximately two-thirds of patients have not yet mutated.

*Based on nonrandomized, observational, retrospective studies that may have unobserved confounding and treatment selection biases as well as other limitations that should be considered when comparing results with clinical trials. Outcomes should be interpreted with caution due to small sample size.

2G=second generation; 2L=second line; 3L=third line; AP=accelerated phase; BP=blast phase; CCyR=complete cytogenetic response; CHR=complete hematologic response; CML=chronic myeloid leukemia; CP=chronic phase; CP-CML=chronic-phase chronic myeloid leukemia; TKI=tyrosine kinase inhibitor.