The clinical trial was terminated due to a change in sponsor strategy.

This is a single-center, single-arm, open, intravenous drug administration of the safety and efficacy of clinical study.

The primary objective of the clinical trial was to evaluate the safety and efficacy of single dose infusion of anti-CLL1 /+CD33 CAR T cells in patients with refractory/recurrent acute myeloid leukemia. A total of about 5 patients with refractory/recurrent acute myeloid leukemia were enrolled in this study, and the target dose range was 1.00~2.50x10^6/kgCAR-positive T cells.

Inclusion Criteria:

1. The patient or his/her legal guardian volunteers for the trial and signs an informed consent form;
2. Age range 1-18 years;
3. Acute myeloid leukemia (AML) with CLL1 and CD33 markers (including secondary patients) was diagnosed by pathology, histology and flow cytometry, or complete hematologic remission could not be achieved after 1 course of chemotherapy for hematologic relapse after drug withdrawal ;
4. The main organ functions of the patients were good: (1) liver function: ALT/AST < 3 times the upper limit of normal (ULN) and bilirubin ≤34.2 μmol/l; (2) renal function: creatinine < 220 μmol/l; (3) lung function: oxygen saturation ≥95% ; (4) cardiac function: left ventricular ejection fraction (LVEF)≥40% ;
5. The blood flow of peripheral superficial vein was unobstructed, which could meet the demands of intravenous drip and mononuclear cell collection;
6. ECOG score was 0-2.

Exclusion Criteria:

1. The patients had uncontrollable infectious diseases within 4 weeks before the enrollment;
2. Active hepatitis B/C virus;
3. HIV infection, treponema syphilis positive patients;
4. Pathological diagnosis of primary tumors other than acute myeloid leukemia;
5. Suffering from serious autoimmune diseases or immunodeficiency diseases;
6. The patient is allergic to antibodies or cytokines and other macromolecular biological drugs;
7. Pregnant or lactating women;
8. Patients who were considered ineligible for study for other reasons.