Journal of Clinical Case Reports

An Unprecedented Case of Myasthenia Gravis Induced by Binimetinib

Abstract

Alabdali M, Bril V, Morgan E, Pereira A and Maurice C

Low-grade serous ovarian cancer, representing 10% of all ovarian cancer diagnoses, is renown for its poor response rate to chemotherapy, despite its indolent course. The MILO study is an international, randomized phase III trial comparing binimetinib, a targeted agent, to standard chemotherapy in patients diagnosed with low-grade serous ovarian cancer. This oral drug is designed to down-regulate cancer cell proliferation and survival through the inhibition of MEK-1 and MEK-2, involved in the RAS/RAF/MEK/ERK signal cascade. We present the case of a 77-year-old female started on binimetinib in November 2014, in a clinical trial context. She developed head drop syndrome correlating exactly with the administration of this drug. The clinical presentation, evolution and electrodiagnostic studies were compatible with myasthenia gravis. Anti-acetylcholine receptor antibodies were not detected. Improvement was noted immediately after the MEK inhibitor was withdrawn.