Novel PLEC-EML4-ALK Double Fusion Underlying Crizotinib Resistance in a Metastatic Inflammatory Myofibroblastic Tumor: A Case Report

ALK fusions are frequent oncogenic drivers in inflammatory myofibroblastic tumors. Treatment with crizotinib is effective in fusion-positive patients; however, acquired resistance remains a challenge. Here, we present a case of EML4-ALK-positive metastatic inflammatory myofibroblastic tumor that ini...

Full description

Saved in:
Bibliographic Details
Main Authors: Alessandra Maleddu, MD, Trista K. Hinz, MS, Margaret A. Black, MD, Dara L. Aisner, MD, PhD, Carrie B. Marshall, MD, Anthony D. Elias, MD, Breelyn A. Wilky, MD, Lynn E. Heasley, PhD, Kurtis D. Davies, PhD
Format: Article
Language:English
Published: Elsevier 2025-05-01
Series:JTO Clinical and Research Reports
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2666364325000074
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ALK fusions are frequent oncogenic drivers in inflammatory myofibroblastic tumors. Treatment with crizotinib is effective in fusion-positive patients; however, acquired resistance remains a challenge. Here, we present a case of EML4-ALK-positive metastatic inflammatory myofibroblastic tumor that initially responded to crizotinib but developed resistance. The progressing lesion revealed the acquisition of a “double fusion” event in which EML4-ALK was additionally fused to PLEC to create a PLEC-EML4-ALK transcript. The double fusion was associated with an increase in ALK expression, mimicking the ALK fusion amplification that is a known mechanism of resistance to crizotinib in lung cancer. On transition to the more potent ALK inhibitor alectinib, the patient exhibited a dramatic response. Thus, the formation of a double fusion represents a novel and targetable mechanism of resistance to crizotinib.
ISSN:2666-3643