Venetoclax with azacitidine and dexamethasone: Non-cytotoxic induction therapy for T-cell leukemia and mixed-phenotype leukemia.

Background: T-lineage acute leukemias are aggressive malignancies for which treatment options are limited. Objectives: This study evaluated the efficacy and safety of a non-cytotoxic regimen combining venetoclax, azacitidine, and dexamethasone (VAD) as first-line induction therapy for T-cell acute lymphoblastic leukemia (T-ALL) and T/myeloid mixed-phenotype acute leukemia (T-Myeloid MPAL). Design: We retrospectively analyzed the clinical parameters and survival data of 11 patients with newly-diagnosed T-ALL or T-Myeloid MPAL who received the VAD regimen. Methods: The complete remission (CR) rate and adverse events were assessed. Kaplan-Meier curves were constructed to evaluate survival outcomes. Results: Among 11 patients (7 with early T-cell precursor [ETP] ALL, 2 with T-Myeloid MPAL, and 2 with non-ETP T-ALL), the overall CR rate after one cycle of VAD therapy was 90.9%, with 45.5% achieving measurable residual disease (MRD) negativity by flow cytometry. The historically poor-prognosis ETP-ALL subgroup showed an 85.7% CR rate (6/7), while both T-Myeloid MPAL cases attained MRD negativity. No tumor lysis syndrome or treatment-related mortality occurred. Over a median follow-up of 358 days, all 5 patients who received transplantations remained relapse-free. Conclusion: The VAD regimen demonstrated a high response rate and favorable safety, enabling effective transplantation bridging with avoidance of conventional cytotoxic therapy.