Abstract
Nivolumab is a newly introduced promising therapy for treating lung cancer that restores the anti-tumor immunity by disrupting programmed cell death-1-mediated immuno-suppressive signaling. Although "new-onset" autoimmune diseases are well-known immune-related adverse events, whether or not nivolumab exacerbates "pre-existing" autoimmune disease remains unclear. We herein report a patient with "pre-existing" myasthenia gravis in whom nivolumab was administered that flared up after the treatment with nivolumab. Regardless of the disease stability, nivolumab has the potential to exacerbate an autoimmune disease, and we must pay close attention to each patient's medical history before administering this agent.