Evaluating Efficacy and Safety of Flumatinib for Chronic Phase Chronic Myeloid Leukemia(CML-CP) Without Optimal Response (Warning,Failure) to Imatinib or Dasatinib

Imatinib has revolutionized the treatment of chronic myeloid leukemia (CML) and is the current standard of care in the treatment of patients with newly diagnosed CML. However, about 30% of patients still show drug resistance or disease progression. Currently, the most widely studied mechanism of TKI resistance in CML patients is mutations in the ABL kinase region. So far, more than 100 kinase domain mutations have been found in disease progression and imatinib resistance. It is estimated that more than 25% of CML patients will change TKI at least once in their lifetime due to drug resistance or intolerance. The 2020 edition of the "Guidelines for the Diagnosis and Treatment of Chronic Myelogenous Leukemia in China" proposes that patients with F317L/V/I/C, V299L and T315A mutations are more likely to obtain clinical efficacy by switching to the second-generation TKI nilotinib; patients with Y253H, E255K/V and F359C/V/I mutations are more likely to obtain clinical efficacy by switching to the second-generation TKI dasatinib; patients with T315I mutations are resistant to both nilotinib and dasatinib. Flumatinib has been shown to be a more potent inhibitor of BCR-ABL1 tyrosine kinase than imatinib. In vitro studies, it has shown that flumatinib inhibits wild-type and common BCR-ABL mutations(Q252H, V299L, F317L/I, M351T, H396P, etc.) more potently, and the anti-mutation spectrum of flumatinib is similar to nilotinib. Therefore, this study is designed to provide clearer guidance for patients with suboptimal response or failure in the treatment of TKI as well as those who have specific ABL kinase domain mutations during CML treatment.