CD19 & CD22 Bispecific CAR T Cells in the Treatment of Relapsed/Refractory B Cell Hematologic Tumors

Since 2010, CAR-T ( chimeric antigen receptor T cell) therapy has shown good results in tumor treatment and has achieved positive clinical therapeutic effects in hematological tumors. The structure of the dual-target CAR-T of CD19 & CD22 is designed with a 4-1BB costimulatory domain and an antigenic recognition region with a tandem structural sequence to recognize CD22 or CD19 by a single structure. CD19 & CD22 bispecific CAR-T cells can identify CD 19 or CD 22 with the advantage that the single target CAR-T does not have, reducing the possibility of target loss. The structure has been optimized to enhance the safety to treat B cell-derived hematological tumors (at least CD19 positive or CD22 positive).

Inclusion criteria

1.CD 19 + / CD 22 + B cell hematological tumor was confirmed by pathological and histological examination, and the patient met the following criteria for relapsed or refractory B cell hematological tumor:

• Refractory / relapsed B lymphocytic leukemia (1 of the following 4 items can be met):

i . Recurrence within 6 months of first remission; ii. Primary refractory without complete remission after 2 cycles of standard chemotherapy regimen; iii. No complete remission or recurrence after first-line or multiline salvage chemotherapy; iv. Not eligible for HSCT conditions, abandonment of HSCT, or relapse after HSCT due to conditional limitations.

• Refractory / relapsed B-cell lymphoma (meet the following item 1 of the first 4 items plus item 5):

i . After four courses of chemotherapy with a standard regimen, tumor shrinkage was less than 50% or disease progression; ii . CR after standard regimen chemotherapy, but relapsed within 6 months; iii.2 or more recurrences after CR; iv . Not suitable for hematopoietic stem cell transplantation, or abandoning HSCT due to conditional restrictions or relapse after hematopoietic stem cell transplantation; v . Subject must have received prior adequate treatment, including at least: a monoclonal antibody against CD 20 and combination chemotherapy containing an anthracycline drug agent.

2.The results of FCM or immunohistochemical detection of tumor antigen (CD 19 / CD 22) were positive.

3.The estimated survival period is more than 3 months starting from the signing of the informed consent form.

4.Good organ function,Meet the following requirements：

• HGB≥70g/L(transfusible)
• Liver and kidney function: creatinine ≤1.5XULN: total bilirubin ≤1.5XULN:ALT and AST≤2.5X ULN
• Cardiopulmonary function: left ventricular ejection fraction >50%; Blood oxygen saturation >90%;

5.Subjects with the Eastern Cooperative Oncology Group (ECOG) fitness scores of 0 to 2.

Exclusion criteria

：(If meet any of the following criteria, patients will not be included)

• Serious heart insufficiency,LVEF <50%
• History of severe pulmonary function impairment disease.
• Other malignant tumors in the advanced stage.
• Severe infection or persistent infection that cannot be effectively controlled.
• Combined with severe autoimmune disease or innate immune deficiency.
• Active hepatitis (hepatitis B virus deoxyribonucleic acid [HBV-DNA 500 IU / ml and abnormal liver function] or hepatitis C antibody [HCV-Ab] positive, HCV-RNA above the lower limit of detection of the analytical method and abnormal liver function).
• Human immunodeficiency virus (HIV) infection or syphilis infection.
• History of severe allergies to biological products (including antibiotics).
• Acute graft-versus-host response (GVHD) allogeneic hematopoietic stem remained one month after immunosuppressant discontinuation.
• Patients who have other serious physical or mental illnesses or abnormalities in laboratory tests that may increase the risk of participating in the clinical trial or interfere with the study results, and who are deemed unsuitable for participation in the clinical trial by the investigator