[Efficacy of chemo-free regimen in treatment of six patients with treatment-naive Philadelphia chromosome-positive mixed phenotype acute leukemia].

To investigate the efficacy of chemo-free regimen in treatment of patients with treatment-naive Philadelphia chromosome positive mixed phenotype acute leukemia(Ph⁺MPAL). The clinical data of patients with newly treated Ph⁺MPAL who received venetoclax (VEN), azacytidine (AZA) and tyrosine kinase inhibitors (TKIs) in the First Affiliated Hospital of Soochow University from July 1, 2021 to October 31, 2023 were retrospectively included. The last follow-up date was December 1, 2024. The complete remission/complete remission with incomplete blood count recovery (CR/CRi), measurable residual disease (MRD), survival and safety were analyzed. A total of 6 patients were included, with 1 male and 5 females, aged 40 (25-52) years. The peripheral white blood count at diagnosis was 191.4 (13.6-344.0)×10⁹/L. All 6 patients had mixed expression of B lineage and myeloid lineage. Philadelphia chromosome was detected in 5 patients, and 3 of them had additional chromosomal abnormalities. All 6 patients achieved response after 1 cycle induction therapy, including 3 patients who achieved CR and 3 patients who achieved CRi. And all 6 patients attained bone marrow MRD negativity. After treatment of 1.5 (0.4-5.9) months, 6 patients achieved molecular remission (MMR). Tow patients experienced recurrence. Five patients received allogeneic hematopoietic stem cell transplantation. The follow-up time was 31.4 (13.1-40.6) months, and all 6 patients were in disease-free survival. Severe adverse events mainly included hematological toxicity and sepsis, and no treatment-related deaths occurred. The VEN+AZA+TKIs chemo-free regimen has good efficacy in treating newly diagnosed Ph⁺MPAL patients.