AL-04. Midostaurin in adult patients with de novo diagnosed FLT3-positive acute myeloid leukemia
Sergey N. Bondarenko1, Anna G. Smirnova1, Bella I. Ayubova1, Yulia Y. Vlasova1, Elena V. Karyagina2, Olga S. Uspenskaya3, Yulia S. Neredko4, Elena A. Pashneva5, Anna P. Kochergina6, Natalia B. Esefyeva7, Tatyana I. Brazkina8, Ridvan K. Ilyasov9, Yulia B. Chernih10, Yurii A. Dunaev11, Irina A. Samorodova12, Olesia G. Smykova1, Ksenia S. Yurovskaya1, Dmitrii K. Zhogolev1, Michail M. Kanunnikov1, Yulia D. Oleynikova1, Ildar M. Barkhatov1, Tatiana L. Gindina1, Ivan S. Moiseev1, Alexander D. Kulagin1
1 RM Gorbacheva Research Institute, Pavlov University, St. Petersburg, Russia
2 City Hospital No. 15, St. Petersburg, Russia
3 Leningrad Regional Clinical Hospital, St. Petersburg, Russia
4 Stavropol Regional Clinical Oncological Dispensary, Stavropol, Russia
5 Volgograd Regional Clinical Oncology Center, Volgograd, Russia
6 Regional Clinical Hospital, Barnaul, Russia
7 Regional Hospital, Ulyanovsk, Russia
8 Regional Hospital, Ivanovo, Russia
9 Crimean V. М. Efetov Republican Oncological Clinical Dispensary, Simferopol, Russia
10 Moscow M. F. Vladimirsky Regional Research Clinical Institute, Moscow, Russia
11 Regional Clinical Hospital, Arkhangelsk, Russia
12 City Hospital No. 31, St. Petersburg, Russia
Contact: Dr. Sergey N. Bondarenko, e-mail: dr.sergeybondarenko@gmail.com
Summary
Mutations in the FMS-like tyrosine kinase 3 (FLT3) gene occur in 20-30% of adult patients with acute myeloid leukemia (AML). Detection of FLT3 mutation is associated with a higher relapse rate (RR) and leads to worse overall (OS) and event-free (EFS) survival. Administration of midostaurin (Mido), a potent FLT3-kinase inhibitor, in AML FLT3+ in combination with chemotherapy (CT) and after allogeneic hematopoietic stem cell transplantation (allo-HSCT) can reduce the relapse rates.
Objective
To evaluate the role of allo-HSCT in adults with FLT3+ AML treated with Mido in CT.
Patients and methods
The study included 74 patients who received CT with Mido in induction, consolidation and maintenance therapy. The median age was 48 (18-74) years. Median follow-up period was 11.7 (1.1-36.8) months. The median level of leukocytes was 50.6 (1.6 to 469.0)×109/L. FLT3-ITD mutation was detected in 61 (82%) patients. The favorable prognostic group ELN2017 (Fav-ELN2017) included 4 (5%) patients; intermediate (Int-ELN2017), 58 (78%) patients; unfavorable prognosis (Unfav-ELN2017) – was assessed in 12 patients (16%).
Results
Complete remission (CR) was achieved in 51 (69%) patients (Fav-ELN2017 – 100%; Int-ELN2017 – 79% and Unfav-ELN2017 – 50%). Early mortality was 8% (6 patients). 17 patients (23%) were primarily refractory. The median duration of CR in Int-ELN2017 was 7.5 (0.5-36) months compared to 4.7 (2.7-35) months in Unfav-ELN2017 group. In the total group, OS was 53 months (95% CI 37-69), and FFS, 37 months (95% CI 23-51). 17(33%) patients developed a relapse at a median of 7 months (2.7-13). The relapse rate was higher in Unfav-ELN2017, 67% compared with 29% in the Int-ELN2017 group. Allo-HSCT was performed in 21(28%) patients, 12 of them were in CR1. After allo-HSCT, Mido was restarted at a median of 75 (31-370) days. The disease-free survival (DFS) was longer when allo-HSCT was performed in CR1, compared with patients without HSCT, i.e., 81 (95% CI 57-99) vs 40 months (95% CI 17-63, p=0.06).
Conclusion
Disease-free survival in adult patients with FLT3+AML is higher after allo-HSCT performed in CR1 compared to the patients who received only CT in combination with Mido.
Keywords
Acute myeloid leukemia, target therapy, midostaurin.
