[Clinical Efficacy and Safety of Flumatinib in the Treatment of Patients with Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase].

Objective: To explore the clinical efficacy and safety of flumatinib mesylate produced in China in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP).

Methods: 32 newly diagnosed CML-CP patients admitted to the Hematology Department of the Affiliated Hospital of Southwest Medical University from March 1, 2020 to March 31, 2022, who had never received any tyrosine kinase inhibitor (TKI) were included in the study. The patients were treated by flumatinib mesylate 600mg once daily. The hematologic, cytogenetic and molecular responses were assessed at 3-, 6- and 12-month, and adverse effects of the drug were evaluated.

Results: 31 patients were treated with flumatinib for≥3 months, of which 24 patients were treated for ≥6 months and 14 patients were treated for≥12 months. At 3rd month of treatment, 30 out of 31 patients achieved complete hematologic response (CHR); 24 patients underwent cytogenetic testing and 22 cases achieved major cytogenetic response(MCyR), of which 21 cases achieved complete cytogenetic response (CCyR); Among 25 patients who underwent molecular testing, 22 patients had BCR-ABL≤10%, including 10 patients with BCR-ABL≤0.1%, and 6 patients with BCR-ABL≤0.01%. At 6th month of treatment, 23 out of 24 patients achieved CHR; 17 patients underwent cytogenetic testing and all achieved CCyR; Among 23 patients who underwent molecular testing, 20 patients had BCR-ABL≤1%, including 16 patients with BCR-ABL≤0.1% and 12 patients with BCR-ABL≤0.01%. At 12nd month of treatment, all 14 patients achieved CHR and CCyR; Among them, 10 patients had BCR-ABL≤0.1%, including 9 patients with BCR-ABL≤0.01%. The grade Ⅲ/Ⅳ leukopenia, thrombocytopenia and anemia rates in the patients were 13.3%, 20.0% and 3.3%, respectively. One patient stopped flumatinib therapy due to severe and persistent hematologic toxicity. The major non-hematologic adverse events were abnormal liver function (20%), diarrhea (10%), bone/joint pain (10%), muscle spasm (10%), rash (6.7%), acute kidney injury (6.7%) and nausea(3.3%), most of which were grade I-II. No patient experienced grade Ⅳ non-hematologic adverse events. No drug toxicity-related death occurred.

Conclusion: Flumatinib mesglate, as the first-line treatment for newly diagnosed CML-CP, can enable the patients to achieve early and deep molecular and cytogenetic responses, and shows good safety.