Acute myeloid leukemia (AML) accounts for about 15% to 20% of childhood leukemia, but the death rate accounts for about 50%. About 20-30% of children with AML did not achieve complete response (CR) after 2 induction treatments, and about 30% of children with CR had relapse within 3 years (including recurrence after hematopoietic stem cell transplantation).Relapsed/refractory (R/R) AML is a major cause of treatment failure and refractory survival. Reinduction chemotherapy for R/R-AML to obtain CR again, followed by hematopoietic stem cell transplantation, is the current treatment. At present, there is no recognized reinduction protocol, and the reinduction remission rate of R/R-AML varies greatly among different treatment regimens, ranging from 23 to 81%. Current guidelines recommend a new combination chemotherapy regimen consisting of new drugs without cross-resistance. This method selects sensitive chemotherapeutic drugs, and then forms a new combination chemotherapy regimen according to the characteristics of drugs, which is the choice of R/R-AML reinduction therapy.This study intends to conduct a clinical study on the individualized treatment of R/R AML patients through in vitro drug sensitivity test combined with patient transcriptomic characteristics.

Inclusion Criteria:

- (1) Refractory recurrent acute myeloid leukemia (AML), and after second-line reinduction therapy, such as C+HAG did not reach complete CR.Criteria for complete response, refractory, and recurrence are as follows.

(2) <18 years old; (3) The child had good organ function, could tolerate chemotherapy, and had a physical strength score of 0-3 (WHO standard); (4) Understand the research procedures and voluntarily sign written informed consent.

Exclusion Criteria:

- (1) Acute promyelocytic leukemia, chronic myelogenous leukemia, acute mixed cell leukemia or known central nervous system leukemia; (2) AML associated with congenital syndromes such as Down syndrome, Fanconi anemia, Bloom syndrome, Cole's syndrome, or congenital aplastic anemia; (3) secondary to immunodeficiency or positive for human immunodeficiency virus (HIV); (4) Cardiac and renal function were obviously abnormal, and left ventricular ejection fraction was <50%.

(5) There is active systemic infection; (6) any medical history or concomitant condition that the investigator believes would impair the subject's safe completion of the study; (7) The investigator considers that the subject is medically unfit to receive the investigational drug or is unfit for any other reason; (8) a known or suspected allergy to the subject drug or to any drug administered in connection with this test;