AL-02. Efficacy and safety of midostaurine in adult patients with newly diagnosed acute FLT3-positive myeloid leukemia
Sergey N. Bondarenko1, Elena V. Morozova1, Anna G. Smirnova1, Bella I. Ayubova1, Elena V. Karyagina2, Olga S. Uspenskaya3, Yulia S. Neredko4, Kamil D. Kaplanov5, Nikolay Yu. Tsvetkov1, Irina A. Samorodova1, Michail M. Kanunnikov1, Yuliya D. Oleynikova1, Ildar M. Barkhatov1, Tatyana L. Gindina1, Alexander D. Kulagin1
1 RM Gorbacheva Research Institute of Pediatric Oncology, Hematology and Transplantation, Pavlov University, St. Petersburg, Russia
2 City Hospital No. 15 of St. Petersburg, Russia
3 Leningrad Regional Clinical Hospital, St. Peterburg, Russia
4 Stavropol Regional Clinical Oncological Dispensary, Stavropol, Russia
5 Volgograd Regional Clinical Oncological Dispensary, Volgograd, Russia
Contact: Dr. Sergey N. Bondarenko, e-mail: dr.sergeybondarenko@gmail.com
Summary
Introduction
FMS-like tyrosine kinase 3 (FLT3) gene mutations occur in 20-30% of adult patients with acute myeloid leukemia (AML). The detection of this mutation is associated with a lower rate of complete remissions and a high rate of relapses, which leads to a deterioration in overall survival in this group of patients. In 2017, the FDA approved the first FLT3 kinase inhibitor midostaurin (Mido) for the treatment of newly diagnosed FLT3 + AML in combination with chemotherapy (ChT). Our aim was to evaluate efficacy and safety of Mido in combination with conventional ChT in adult AML*.
Patients and methods
The study included 17 patients (pts) who received CT “7+3”with Mido. The median age was 56.5 (25 to 72) years. Median follow-up was 7.5 (1-12.8) mo. The FLT3-ITD mutation was detected in 15 pts (88%), FLT3-TKD mutation, in 2 cases (12%). Additional mutations were also found: NPM1, in 3 pts; IDH1, in 1 patient. All the pts were referred to the intermediate prognostic group according to the ELN 2017 classification.
Results
Complete remission (CR) was achieved in 11 (65%) pts after the 1st ChT cycle. Early mortality was 23% (4 pts), due to infectious complications (sepsis, infectious toxic shock, neutropenic enteropathy). A primary refractory course (no response to 2 cycles of CT with Mido) was documented in two cases (12%). Two pts developed an early relapse. One of them proceeded with bone marrow affection and recurrent FLT3 mutation, and the second, with extramedullary skin lesions without FLT3 mutation, respectively, 3 and 6 mo later. The median CR duration was 5.5 (1.5 to 12.1) mo. Currently, 12 (71%) of the pts are alive. Febrile neutropenia was observed in 13pts (76%); sepsis, in 4 cases (23%); enteropathy with neutropenia was observed in 1 case. Dyspeptic disorders on the background of Mido treatment manifested as nausea and vomiting in 3 pts, diarrhea in 5 cases. Two pts each had headaches, joint pains and increased blood pressure. The drug was discontinued in one case, due to supraventricular tachycardia.
Conclusion
This study has demonstrated efficacy and acceptable toxicity profile upon administration of FLT3 inhibitors combined with standard СhT.
* Mido was provided as a part of the Early Access Program.
Keywords
Acute myeloid leukemia, targeted therapy, midostaurin.
