Checkpoint inhibitor-related myasthenia-myocarditis-myositis overlap syndrome in the orbit.

We report a series of three patients who developed checkpoint inhibitor-related myocarditis with orbital myositis and/or myasthenia gravis overlap syndrome, with varying degrees of severity. In all cases, checkpoint inhibitor therapy was immediately discontinued upon diagnosis and corticosteroids were initiated. While two patients achieved substantial recovery, one patient passed away on hospital day three. These cases underscore the critical need for prompt recognition of adverse events associated with immune checkpoint inhibitors.