Successful Treatment of Non-langerhans Cell Histiocytosis With the Mek Inhibitor Trametinib: A Multicenter Analysis

Authors

Ashley Aaroe
Razelle Kurzrock
Gaurav Goyal
Aaron M Goodman
Harsh Patel
Gordon Ruan
Gary Ulaner
Jason Young
Ziyi Li
Derek Dustin
Ronald S Go
Eli L Diamond
Filip Janku

Publication Date

8-8-2023

Journal

Blood Advances

Abstract

Erdheim-Chester disease (ECD) and Rosai-Dorfman disease (RDD) are rare non-Langerhans cell histiocytoses (non-LCHs), for which therapeutic options are limited. MAPK pathway activation through BRAFV600E mutation or other genomic alterations is a histiocytosis hallmark and correlates with a favorable response to BRAF inhibitors and the MEK inhibitor cobimetinib. However, there has been no systematic evaluation of alternative MEK inhibitors. To assess the efficacy and safety of the MEK inhibitor trametinib, we retrospectively analyzed the outcomes of 26 adult patients (17 with ECD, 5 with ECD/RDD, 3 with RDD, and 1 with ECD/LCH) treated with orally administered trametinib at 4 major US care centers. The most common treatment-related toxicity was rash (27% of patients). In most patients, the disease was effectively managed at low doses (0.5-1.0 mg trametinib daily). The response rate of the 17 evaluable patients was 71% (73% [8/11] without a detectable BRAFV600E achieving response). At a median follow-up of 23 months, treatment effects were durable, with a median time-to-treatment failure of 37 months, whereas the median progression-free and overall survival were not reached (at 3 years, 90.1% of patients were alive). Most patients harbored mutations in BRAF (either classic BRAFV600E or other BRAF alterations) or alterations in other genes involved in the MAPK pathway, eg, MAP2K, NF1, GNAS, or RAS. Most patients required lower than standard doses of trametinib but were responsive to lower doses. Our data suggest that the MEK inhibitor trametinib is an effective treatment for ECD and RDD, including those without the BRAFV600E mutation.

Keywords

Adult, Humans, Proto-Oncogene Proteins B-raf, Retrospective Studies, Erdheim-Chester Disease, Histiocytosis, Sinus, Protein Kinase Inhibitors, Mitogen-Activated Protein Kinase Kinases

DOI

10.1182/bloodadvances.2022009013

PMID

36857436

PMCID

PMC10410131

PubMedCentral® Posted Date

8-8-2023

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes