A 76-year-old woman who was diagnosed with non-small-cell lung cancer presented with left eyelid ptosis and grade 4 creatine phosphokinase elevation after the second cycle of nivolumab monotherapy. Nivolumab has demonstrated promising efficacy in patients with non-small-cell lung cancer in several trials. Dyspnea and muscle weakness developed rapidly with an acute exacerbation. She underwent plasmapheresis and intravenous immune globulin followed by treatment with low-dose prednisolone. She had gradual symptoms improvement. We diagnosed her with myasthenia gravis (MG) based on her symptoms and the detection of anti-acetylcholine receptor antibody. According to postmarketing surveillance in 15,740 Japanese patients, the total incidence rate of MG is 0.1%. We report a rare case of drug-induced MG in a patient receiving nivolumab.
Keywords: myasthenia gravis; nivolumab; non-small-cell lung cancer.