A Study of Anti-CD7 CAR-T Cells in Pediatric and Young Adult Patients With Relapse and Refractory T-ALL/ T-LBL

Inclusion Criteria: 1. 2 to 25 years 2. Diagnosed with relapsed and refractory CD7 + T cell acute lymphocytic leukemia (T-ALL) or relapsed and refractory CD7 + T lymphoblastic lymphoma (T-LBL) 3. Quantifiable tumor burden 4. Eastern cooperative oncology group (ECOG) performance status of 0 to 1 5. Life expectancy ≥12 weeks 6. Adequate organ function defined as: 1. Serum ALT/AST ≤2.5 ULN 2. Creatinine clearance (as estimated by Cockcroft Gault) ≥60 mL/min 3. PT and APTT≤1.5 ULN 4. Total bilirubin ≤1.5 ULN 5. Cardiac ejection fraction ≥45% 6. No clinically significant ECG findings 7. Baseline oxygen saturation \>90% on room air 7. Recovered from acute toxic effects of prior chemotherapy ≥one week before entering this study 8. Agreement to use of medical-approved-contraception during the period of trial and in 1 year after cell transfusion therapy 9. Signed informed consent form Exclusion Criteria: 1. Diagnosis of other malignancy (except non-melanoma and cervical carcinoma in situ, bladder cancer, breast cancer that have a disease-free survival of more than 5 years) 2. Severe mental disorders 3. History of hereditary diseases, including but not limited to: Fanconi anemia, Shut-Dai syndrome, Costman syndrome or any other known bone marrow failure syndrome 4. Grade 2-4 acute graft-versus-host disease (GVHD) (Glucksberg criteria) or extensive chronic GVHD (Seattle criteria) 5. Grade III-IV heart failure or myocardial infarction, angioplasty or stent placement, unstable angina pectoris, or other clinically prominent heart disease within one year before enrollment 6. History or presence of CNS disorder, including but not limited to: seizure disorder, cerebrovascular ischemia/hemorrhage, dementia, cerebellar disease, or any autoimmune disease with CNS involvement 7. Positive for any of the following etiological tests: HIV, HBV, HCV, TPPA 8. Presence of fungal, bacterial, viral, or other infection that is uncontrolled 9. Severe allergies 10. History of autoimmune disease resulting in end organ injury or requiring systemic immunosuppression/systemic disease modifying agents within the last 2 years 11. History or diagnosis of pulmonary fibrosis 12. Participation in other clinical trials ≤4 weeks prior to enrollment 13. Concomitant disease that require systemic steroids or other immune suppressive therapy during the study period in researcher's judgement 14. Patients who are contraindicated to cyclophosphamide, fludarabine 15. Allogeneic cell therapy (such as donor lymphocyte infusion, DLI) ≤6 weeks prior to enrollment 16. Poor adherence due to physical, family, social, geographic, and other factors, who cannot follow the research plan and follow-up plan 17. Pregnant and lactating women 18. Any other conditions that researcher think it is inappropriate for the subject to anticipate the trial