Extramedullary relapse of acute myeloid leukemia (AML) is not a rare event, and the FMS-like tyrosine kinase 3 (FLT3) mutation is a well-known risk factor. Gilteritinib is approved for relapsed/refractory FLT3+ AML, but its efficacy in extramedullary relapse is still undefined. Here, we present the case of a 69-year-old woman with therapy-related nucleophosmin-1 and FLT3-internal tandem duplication (FLT3-ITD) positive AML treated with induction and consolidation with CPX-351 (liposomal daunorubicin plus cytarabine) followed by off-label azacitidine maintenance who obtained a complete remission (CR) with persistent measurable residual disease. After 19 months of CR, she experienced an isolated breast relapse of FLT3-ITD+ AML. She was started on single-agent gilteritinib, resulting in a rapid and persistent complete regression of the breast nodule. Targeted therapy with gilteritinib for relapsed/refractory FLT3-ITD+ AML can be effective in isolated extramedullary relapse.

Keywords:
Breast myeloid sarcoma, Acute myeloid leukemia, Extramedullary involvement, FMS-like tyrosine kinase 3-internal tandem duplication, Gilteritinib
© 2022 S. Karger AG, Basel
2022
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.