This is a single arm study to evaluate the efficacy and safety of CD123-targeted CAR-T cells therapy for patients with relapsed/refractory Acute Myeloid Leukemia.

There are limited options for treatment of relapse/refractory Acute Myeloid Leukemia. CD123 is expressed on most myeloid leukemia cells so it is an ideal target for CAR-T. Some researches have revealed that CD123 is a marker of leukemia stem cells, which indicates that the eradication of CD123 cells may prevent relapse of leukemia. In this study, investigators will evaluate the safety and efficacy of CAR-T targeting CD123 in patients with relapsed/refractory Acute Myeloid Leukemia. The primary goal is safety and efficiency assessment, including adverse events and disease status after treatment.

Inclusion Criteria:

1. Signed written informed consent;

2. Diagnose as relapsed /refractory acute myeloid leukemia, and meet one of the following conditions:

   1. Failed to standard chemotherapy regimens;
   2. Relapse after complete remission, high-risk and / or refractory patients ;
   3. Relapse after hematopoietic stem cell transplantation;

3. Evidence for cell membrane CD123 expression;

4. All genders, ages: 3 to 75 years；

5. The expect time of survive is above 12 weeks;

6. KPS>60；

7. No serious mental disorders ;

8. Left ventricular ejection fraction ≥50%

9. Sufficient hepatic function defined by ALT/AST≤3 x ULN and bilirubin≤2 x ULN;

10. Sufficient renal function defined by creatinine clearance≤2 x ULN;

11. Sufficient pulmonary function defined by indoor oxygen saturation≥92%;

12. With single or venous blood collection standards, and no other cell collection contraindications;

13. Ability and willingness to adhere to the study visit schedule and all protocol requirements.

Exclusion Criteria:

1. Have received CAR-T therapy or other genetically modified cell therapy before screening；
2. Participated in other clinical research within 1 month before screening；
3. Have received the following anti-tumor treatment before screening: Have received chemotherapy, targeted therapy or other experimental drug treatment within 4 weeks, except those who have confirmed disease progression after treatment;
4. Live attenuated vaccine within 4 weeks before screening;
5. Convulsion or stoke within past 6 months;
6. Previous history of other malignancy;
7. Presence of uncontrolled active infection;
8. Subjects with positive HBsAg or HBcAb positive and peripheral blood HBV DNA titer is higher than the lower limit of detection of the research institution; HCV antibody positive and peripheral blood HCV RNA titer is higher than the lower limit of detection of the research institution; HIV antibody positive; syphilis primary screening antibody positive;
9. Pregnant or breasting-feeding women;
10. Any situation that investigators regard not suitable for attending in this study or may affect the data analysis.