Acute T cell lymphoblastic leukemia/lymphoma (T-ALL/LBL) is an aggressive type of leukemia that results from the malignant evolution of T-lineage progenitor cells at different differentiation stages. After induction chemotherapy and consolidation chemotherapy, there are still about 30% of patients who cannot achieve complete remission of clinical symptoms or negative MRD. This is also an important factor for the recurrence of ALL patients. In addition, most relapsed T-ALL/LBL patients relapse during first-line treatment. Once the disease relapses, it is difficult to cure for most young and adult patients, and the overall survival rate of patients is less than 10%.

This is a prospective, single-arm, phase II and open-label study. A total of 50 R/R T-ALL/LBL participants will be enrolled. The primary endpoint is complete remission with or without peripheral blood cell recovery. The induction therapy is a combination of Venetoclax(Ven), Homoharringtonine(HHT) , Cytarabine and G-CSF. The purpose of this study is to explore efficacy of the VHAG in the treatment of R/R T-ALL/LBL patients.

Inclusion Criteria:

• 1. Before enrollment, a diagnosis of newly diagnosed T-cell acute leukemia/lymphoma.The diagnostic criteria refer to the 2022 WHO classification; 2. Age ≥ 14 years,<75 years; 3. Clincally diagnosed as relapsed or refractory T-ALL/LBL; 4. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2; 5. Expected survival time ≥ 2 months; 6. No organ dysfunction that would restrict the use of this protocol during the screening period; 7. Understand the study and sign the informed consent form.

Exclusion Criteria:

• 1. Patients with known central nervous system (CNS) involvement of T-ALL/LBL; 2. Diseases with abnormal heart, lung, liver, kidney, or other organ functions that may limit the patient's participation in this trial (including but not limited to severe infections, uncontrolled diabetes, severe heart failure or angina, active pulmonary tuberculosis, asthma, COPD, bronchiectasis, etc.) 3. Cardiac ultrasound LVEF < 45%; 4. History of other malignancies within the past 5 years, excluding localized thyroid cancer and in situ skin cancer; 5. Serum total bilirubin > 1.5 ULN (upper limit of normal); ALT or AST > 2.5 ULN; serum creatinine > 1.5 ULN; 6. Known HIV infection; 7. Conditions affecting the use of the study drug as assessed by the investigator; 8. Inability to understand or comply with the study protocol.