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.

