Characterization of Immune Checkpoint Inhibitor-Induced Myasthenia Gravis Using the United States Food and Drug Administration Adverse Event Reporting System.

Myasthenia gravis (MG) is a rare but fatal adverse event of immune checkpoint inhibitors (ICI). We assessed whether patient characteristics differed between those with immune checkpoint inhibitor-related MG and those with idiopathic MG. Reports from the United States Food and Drug Administration Adverse Event Reporting System were analyzed. Multivariate analyses were conducted to evaluate the associations between age, sex, and ICI treatment and the reporting rate of MG. Among 5,464,099 cases between 2011 to 2019, 53,447 were treated with ICIs. MG was reported more often in ICI user. Multiple logistic regression analyses showed that the reporting rate of ICI-related MG did not differ significantly between male and female; however, it was higher in older people than in younger people (adjusted odds ratio, 2.4 [95% confidence interval: 1.84-3.13]). We also investigated useful signs for the early detection of myositis and myocarditis, which are fatal when overlapping with ICI-related MG. Patients with elevated serum creatine kinase or troponin levels were more likely to have concurrent myositis and myocarditis. Unlike idiopathic MG, there was no sex difference in the development of ICI-related MG, which may be more common in older people. Considering the physiological muscle weakness that occurs in the elderly, it may be necessary to monitor ICI-related MG more closely in older people. This article is protected by copyright. All rights reserved.