Pembrolizumab-induced myasthenia gravis: A rare immune-related adverse event in a patient treated for bladder cancer

Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1, such as pembrolizumab, are widely used for the treatment of various malignancies. These therapies, while typically less toxic than traditional chemotherapy, are associated with immune related adverse events which may affect the gastrointestinal tract, lungs, skin, liver, and less commonly the nervous system. Neurologic irAE are rare but carry high mortality rates. We present a case of seronegative myasthenia gravis in a patient treated with pembrolizumab for refractory bladder cancer. This case highlights the importance of early recognition of neurologic manifestations of irAE in patients receiving therapy with ICIs.