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Updated: May 7, 2026

A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors
12:40

A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors

Published on: December 7, 2014

Progression of RAS-mutant leukemia during RAF inhibitor treatment

Margaret K Callahan1, Raajit Rampal, James J Harding

  • 1Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.

The New England Journal of Medicine
|November 9, 2012
PubMed

Insights

Vemurafenib, a RAF inhibitor, can paradoxically activate ERK signaling, leading to the accelerated growth of RAS-mutant leukemia. This effect was reversed upon vemurafenib withdrawal, highlighting a critical safety concern.

Area of Science:

  • Oncology
  • Molecular Biology
  • Dermatology

Background:

  • Vemurafenib is a selective RAF inhibitor that improves survival in patients with BRAF V600E-mutant melanoma.
  • While inhibiting ERK signaling in BRAF V600E-mutant cells, vemurafenib paradoxically activates ERK signaling in BRAF wild-type cells.

Observation:

  • Paradoxical ERK signaling activation by vemurafenib is linked to the development of RAS-mutant skin cancers.
  • A patient with melanoma receiving vemurafenib developed an unsuspected RAS-mutant leukemia.

Findings:

  • Vemurafenib exposure led to hyperactivation of ERK signaling and proliferation in the leukemic cells.
  • Cessation of vemurafenib reversed the ERK signaling hyperactivation and leukemic cell growth.

Implications:

  • This case highlights a potential mechanism for vemurafenib-induced leukemia in patients with RAS mutations.
  • Clinicians should consider the risk of paradoxical ERK activation and potential for secondary malignancies in patients treated with RAF inhibitors.

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