The combination of an anthracycline and cytosine arabinoside has been the standard induction therapy for acute myeloid leukemia (AML) for more than four decades. Fetal liver tyrosine kinase 3 (FLT3) mutations are among the most frequently found mutations in newly diagnosed AML. According to the results of RATIFY trial, midostaurin was approved for use together with intensive chemotherapy (cytarabine plus daunorubicin). Recently, idarubicin has been more frequently favored over daunorubicin.

Report the outcome of patients with AML and FLT3 mutated treated with a combination of cytosine arabinoside plus anthracycline (“7+3”regimen) and midostaurin.

Herein, we retrospectively analyzed the treatment outcome of three patients with newly diagnosed AML and confirmed FLT3-ITD were eligible. The treatment consisted induction with “7+3”regimen and midostaurin (administered at a dose of 50 mg orally twice daily on days 8 through 21).

All were male with age between 21 and 38 years old. A normal karyotype was found in all cases. Patients received cytarabine, idarubicin and midostaurin for induction and all experienced febrile neutropenia and two necessitated preemptive liposomal amphotericin B. One patient developed neutropenic enterocolitis. A second course of induction chemotherapy was administered to 2 patients. Relapse was observed in 1 patient (after Allo-HCT). One patient died after allo-HCT due to severe acute GVHD and one patient is alive in CR1.

We showed that young patients, who had AML and a FLT3-ITD mutation, can be treated with the combination of cytarabine, idarubicin and midostaurin. The RATIFY study (Stone et al., 2017) and the German-Austrian AML Study Group (Schlenk et al., 2019) used daunorubicin 60 mg/m2 for induction, in combination with cytarabine and midostaurin. The complete remission rates in these trials were 59.8% (CR – Ratify) and 77.9% (CR+Cri - German-Austrian trial). In contrast with these two studies, idarubicin was used for induction in 53.5% of cases and was favored over daunorubicin in a more recent trial (Sierra et al. 2020). Of note, the results of FLT3 are necessary before the day 8 of induction. Hence, some patients may have already received the all three planned doses of anthracycline (idarubicin) before the information on results of FLT3 mutation.

The recent approvals of new drugs for treating AML will modify the treatment algorithm and our data indicate that the use of idarubicin in combination with cytarabine and midostaurin is feasible in young patients with FLT3-mutated AML.