A serious case of multiple site muscle damage secondary to the use of immune checkpoint inhibitor of PD-L1

Excerpt

Immune checkpoint inhibitors (ICIs) such as antibodies targeting programmed cell death 1 (PD-1), PD-1 ligand (PD-L1), and cytotoxic T lymphocyte associated antigen 4 (CTLA-4) are the major advances in cancer therapy in the recent two decades [1]. These drugs eliminate cancer cells by “releasing the brakes” on T cell activation pathway, i.e. enhancing immune surveillance. This modulatory mechanism inevitably leads to pleiotropic immune related adverse events (irAEs) which include neuromuscular involvement manifesting as myositis, polymyalgia rheumatica, myocarditis, myasthenia syndrome, and peripheral neuropathy [2]. Avelumab is an anti-PD-L1 antibody which was first approved for metastatic Merkel cell carcinoma and locally advanced or metastatic urothelial carcinoma with ineffective response to platinum-containing chemotherapy. Subsequently, it was approved for the maintenance treatment for patients with locally advanced or metastatic urothelial carcinoma that has not progressed with first line platinum containing chemotherapy. Here we describe a case presenting with myositis, myocarditis and myasthenia gravis early after avelumab treatment. …