This is a single center, single arm, open-lable phase I study to determine the safety and efficacy of T cells expressing CD7 chimeric antigen receptors (referred to as "BT-007 CAR-T cells") in patients with relapsed or refractory acute T cell lymphoblastic lymphoma (R/R T-LBL).

Primary objective:

To investigate the safety and efficacy of CD7 CAR-T cells in the treatment of patients with relapsed or refractory acute T cell lymphoblastic lymphoma (R/R T-LBL).

Secondary objective:

To assess the patient's quality of life after receiving the treatment.

Inclusion Criteria:

1. Patients with CD7 positive T-cell lymphoma confirmed by histology;
2. Relapsed refractory patients who received at least one line of systemic chemotherapy in the past;
3. At least one measurable target lesion;
4. Age: 18-70 years old (including 18 and 70 years old);
5. The expected survival period is more than 3 months;
6. Eastern Cooperative Oncology Group (ECOG) score 0-1;
7. Important organ functions met: left ventricular ejection fraction≥50% according to cardiac ultrasound; Serum Cr≤1.25 times the upper limit of normal range (ULN) or endogenous creatinine clearance≥45mL/min (Cockcroft Gault formula); ALT and AST≤3 times ULN, TBIL≤1.5 times ULN;
8. Blood routine: hemoglobin (Hgb)≥80g/L, neutrophil count (ANC)≥1×10^9/L, platelet PLT≥50×10^9/L；
9. Coagulation function: International standardized ratio (INR)≤1.5 times ULN; Activated partial thromboplastin time (APTT)≤1.5 times ULN (unless the subject is receiving anticoagulant treatment, and prothrombin time (PT)/INR and APTT are within the expected range of anticoagulant treatment at the time of screening);
10. The pregnancy test of women of childbearing age must be negative; Both male and female patients need to agree to use effective contraceptive measures during the treatment period and within the following 1 year;
11. Participate in this test voluntarily and sign the informed consent.

Exclusion Criteria:

1. Used immunosuppressive agents or therapeutic doses of corticosteroids (defined as prednisone>20mg or equivalent dose) within one week before blood collection, or used drugs that stimulate bone marrow hematopoiesis, such as Human Granulocyte Colony Stimulating Factor (G-CSF); But physiological substitution, topical or inhaled steroids are permitted;
2. Uncontrolled systemic active fungi, bacteria, viruses or other infections;
3. Active hepatitis B (HBV DNA>500IU/mL), hepatitis C (HCV RNA positive) or human immunodeficiency virus (HIV) antibody positive;
4. Central nervous system invasion, or central nervous system disease history, such as epilepsy, cerebrovascular disease, etc;
5. Pregnant or lactating women, or patients do not agree to use effective contraceptives during treatment and within the following 1 year;
6. Receiving allogeneic hematopoietic stem cell transplantation or organ transplantation;
7. Previous history of other malignant tumors. Patients with cured skin basal or squamous cell carcinoma and cervical carcinoma in situ at any time before the study were not included; Patients with other tumors not listed above, but which have been cured by surgery but not by other further treatment measures, and disease-free survival≥5 years, can be included in the study;
8. Patients with primary immunodeficiency or autoimmune diseases, but asymptomatic hypothyroidism, or well controlled type I diabetes can participate in this study;
9. Patients who participated in other clinical trials within 4 weeks before blood collection;
10. The investigator considers that there are other factors that are not suitable for inclusion or affect the subjects to participate in or complete the study.