Serious adverse events with tocilizumab: Pharmacovigilance as an aid to prioritize monitoring in COVID-19

Given its approval for the treatment of cytokine release syndrome, tocilizumab is under investigation in severe coronavirus disease-2019. To characterize serious adverse events (AEs) with tocilizumab, we queried the worldwide FDA Adverse Event Reporting System and performed disproportionality analysis, selecting only designated medical events (DMEs) where tocilizumab was reported as suspect, with a focus on hepatic reactions. The reporting odds ratios (RORs) were calculated, deemed significant by a lower limit of the 95% confidence interval (LL 95% CI) > 1. A total of 2,433 reports of DMEs were recorded with tocilizumab, mainly in rheumatic diseases. Statistically significant RORs emerged for 13 DMEs, withdrug-induced liver injury(n= 91; LL 95% CI 3.07),pancreatitis(151; 1.41), andpulmonary fibrosis(222; 7.21) as unpredictable AEs. A total of 174 cases of liver-related DMEs were retrieved (proportion of deaths = 18.4%), with median onset of 27.5 days. These serious unpredictable reactions occurring in chronic real-world tocilizumab use may support patient care and monitoring of ongoing clinical trials.