Bridging to transplant and post-transplant maintenance therapy with FLT3 inhibitors in patients with relapsed or refractory FLT3 mutated acute myeloid leukemia

• Published in: Hematology (Luxembourg) Vol. 28; no. 1; p. 2220518
• Main Authors: Hirose, Natsuki, Tachibana, Takayoshi, Izumi, Akihiko, Sato, Shuku, Tadera, Noriyuki, Tamai, Yotaro, Kanamori, Heiwa, Tanaka, Masatsugu, Nakajima, Hideaki
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 31.12.2023; Taylor & Francis Group
• Subjects: Acute myeloblastic leukemia; bridging; FLT3 inhibitors; fms-Like Tyrosine Kinase 3 - genetics; Hematopoietic Stem Cell Transplantation; Humans; Leukemia, Myeloid, Acute - drug therapy; Leukemia, Myeloid, Acute - therapy; maintenance therapy; Mutation; Phenylurea Compounds - therapeutic use; Protein Kinase Inhibitors - adverse effects; Recurrence; Retrospective Studies; transplantation; maintenance therapy; Acute myeloblastic leukemia; FLT3 inhibitors; bridging; transplantation
• ISSN: 1607-8454; 1607-8454
• DOI: 10.1080/16078454.2023.2220518

This single-center retrospective study was performed to evaluate the safety and efficacy of FMS-like tyrosine kinase 3 (FLT3) inhibitors before and after allogeneic hematopoietic cell transplantation (HCT) in relapsed/refractory patients with FLT3-mutation positive acute myeloid leukemia (AML). Ten patients who met the eligibility criteria were included. Eight of them achieved hematological remission at HCT, within a median span of 79 days (range: 43-197). In post-HCT, patients started maintenance therapy (MT; median time-to-start 79 days, range: 43-197), and the median duration of MT was 390 days (range: 67-815). Grade 3 hematological adverse events (AEs) were found in two patients, and non-hematological AEs were found in five patients. Nine patients underwent either dose reduction, discontinuation of therapy, or a switch to another FLT3 inhibitor due to AEs. Disease relapse occurred in one patient during MT. At the time of the last follow-up, seven patients are alive and disease-free, while three have died due to infection or transplant complications. In relapsed/refractory FLT3 mutation-positive AML, the use of FLT3 inhibitors can lead to high response rates and provide a safe bridge from HCT to MT. If sufficient attention is paid to safety, this therapy is expected to prevent disease relapse even with reduced dosages.