CD19 expression on B cell frequently lost after CD19-targeting CAR-T therapy. In present study, we construct a CD22-targeting chimeric antigen receptor to overcome this issue.

CD19 is an ideal target with great potential for treating B-cell-derived hematological malignancies. Although the complete remission rate is as high as 93% by using CD19-targeting CAR-T technology, approximately 60% patients will have recurrent disease. Among all the recurrent patients, two thirds is revealed to loss their CD19 expression on B cell surface. For overcoming this issue, we establish a new chimeric antigen receptor containing humanized single chain antibody sequence to target CD22 molecule on B cells.

Inclusion Criteria:

• Greater than four years of age
• Survival time>12 weeks
• B cell hematological malignancies by pathological examination
• Chemotherapy failure or recurrent B cell malignancy
• Creatinine< 2.5mg/dl
• Glutamic-pyruvic transaminase, glutamic oxalacetic transaminase< 3 fold of normal level
• Bilirubin<2.0mg/dl
• Karnofsky Performance Status>50% at the time of screening
• Adequate pulmonary, renal, hepatic, and cardiac function
• Fail in autologous or allogenic haemopoietic stem cell transplantation
• Free of leukocytes removal contraindications
• Voluntarily join CAR-T clinical trial
• Understand and sign written informed consent

Exclusion Criteria:

• Pregnant or nursing women
• Active hepatitis B, active hepatitis C, or any human immunodeficiency virus (HIV) infection at the time of screening
• Feasibility assessment proves that the efficiency of transduction of lymphocyte is below 10% or the lymphocyte cannot be propagated.
• Abnormal vital signs
• Highly allergic constitution or history of severe allergies, especially allergy to interleukin-2
• General infection or local severe infection, or other infection that is not controlled
• Dysfunction in lung, heart, kidney and brain
• Severe autoimmune diseases
• Other symptoms that are not applicable for CAR-T