A Case of Pembrolizumab-Induced Myasthenia Gravis

Abstract

With the advent of new cancer treatments, immunotherapy has emerged as an increasingly promising strategy. Undoubtedly, it has pushed oncology into a new era and is providing patients with unprecedented results. As with many treatments, however, adverse effects lead to setbacks in progress. Pembrolizumab is an immunomodulating medication that functions by binding to programmed cell death protein 1 (PD-1) receptors of T cells thereby upregulating the immune system to more effectively detect and target cancer. Myasthenia gravis (MG) is a reported side effect of this medication. Our patient is an 87-year-old male with urothelial cell bladder cancer who developed MG following the administration of pembrolizumab and was treated with plasma exchange therapy. We aim to examine the existing literature concerning treatments for MG, with a particular focus on myasthenia gravis induced by pembrolizumab. We will discuss the occurrence rates and results of such instances, along with their implications for the future of these potential therapies.

Keywords: immune-checkpoint inhibitors; immune-related adverse event (irae); immunotherapy toxicity; keytruda induced myositis; keytruda®; myasthenia gravis; pembrolizumab; pembrolizumab induced myasthenia gravis; seronegative myasthenia gravis.