Efficacy of MEK inhibition in patients with histiocytic neoplasms Journal Article


Authors: Diamond, E. L.; Durham, B. H.; Ulaner, G. A.; Drill, E.; Buthorn, J.; Ki, M.; Bitner, L.; Cho, H.; Young, R. J.; Francis, J. H.; Rampal, R.; Lacouture, M.; Brody, L. A.; Ozkaya, N.; Dogan, A.; Rosen, N.; Iasonos, A.; Abdel-Wahab, O.; Hyman, D. M.
Article Title: Efficacy of MEK inhibition in patients with histiocytic neoplasms
Abstract: Histiocytic neoplasms are a heterogeneous group of clonal haematopoietic disorders that are marked by diverse mutations in the mitogen-activated protein kinase (MAPK) pathway 1,2 . For the 50% of patients with histiocytosis who have BRAF V600 mutations 3–5 , RAF inhibition is highly efficacious and has markedly altered the natural history of the disease 6,7 . However, no standard therapy exists for the remaining 50% of patients who lack BRAF V600 mutations. Although ERK dependence has been hypothesized to be a consistent feature across histiocytic neoplasms, this remains clinically unproven and many of the kinase mutations that are found in patients who lack BRAF V600 mutations have not previously been biologically characterized. Here we show ERK dependency in histiocytoses through a proof-of-concept clinical trial of cobimetinib, an oral inhibitor of MEK1 and MEK2, in patients with histiocytoses. Patients were enrolled regardless of their tumour genotype. In parallel, MAPK alterations that were identified in treated patients were characterized for their ability to activate ERK. In the 18 patients that we treated, the overall response rate was 89% (90% confidence interval of 73–100). Responses were durable, with no acquired resistance to date. At one year, 100% of responses were ongoing and 94% of patients remained progression-free. Cobimetinib treatment was efficacious regardless of genotype, and responses were observed in patients with ARAF, BRAF, RAF1, NRAS, KRAS, MEK1 (also known as MAP2K1) and MEK2 (also known as MAP2K2) mutations. Consistent with the observed responses, the characterization of the mutations that we identified in these patients confirmed that the MAPK-pathway mutations were activating. Collectively, these data demonstrate that histiocytic neoplasms are characterized by a notable dependence on MAPK signalling—and that they are consequently responsive to MEK inhibition. These results extend the benefits of molecularly targeted therapy to the entire spectrum of patients with histiocytosis. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
Keywords: adult; cancer chemotherapy; clinical article; aged; gene mutation; drug efficacy; drug safety; cancer patient; prospective study; letter; gene; enzyme inhibition; phase 2 clinical trial; genotype; histiocytosis; oncogene k ras; braf gene; nras gene; lymphatic system tumor; mek1 gene; mapk signaling; human; male; female; priority journal; histiocytic neoplasm; cobimetinib; araf gene; mek2 gene; raf1 gene
Journal Title: Nature
Volume: 567
Issue: 7749
ISSN: 0028-0836
Publisher: Nature Publishing Group  
Date Published: 2019-03-28
Start Page: 521
End Page: 524
Language: English
DOI: 10.1038/s41586-019-1012-y
PUBMED: 30867592
PROVIDER: scopus
PMCID: PMC6438729
DOI/URL:
Notes: Source: Scopus
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MSK Authors
  1. Mario E Lacouture
    457 Lacouture
  2. Gary Ulaner
    146 Ulaner
  3. Neal Rosen
    425 Rosen
  4. Robert J Young
    228 Young
  5. Jasmine Helen Francis
    256 Francis
  6. Alexia Elia Iasonos
    362 Iasonos
  7. Raajit Kumar Rampal
    338 Rampal
  8. David Hyman
    354 Hyman
  9. Lynn Brody
    119 Brody
  10. Eli Louis Diamond
    202 Diamond
  11. Esther Naomi Drill
    93 Drill
  12. Ahmet Dogan
    454 Dogan
  13. Benjamin Heath Durham
    115 Durham
  14. Hana Cho
    21 Cho
  15. Neval   Ozkaya
    28 Ozkaya
  16. Justin J Buthorn
    22 Buthorn
  17. Michelle Carmen Ki
    16 Ki
  18. Lillian Elizabeth Bitner
    12 Bitner