Immune-Related Adverse Events Associated with Atezolizumab: Insights from Real-World Pharmacovigilance Data

The advancement of immuno-oncology has brought about a significant shift in cancer treatment methods, with antibody-based immune checkpoint inhibitors like atezolizumab leading the way in this regard. However, the use of this checkpoint blockade can result in immune-related adverse events due to increased T-cell activity. The full spectrum of these events is not yet completely understood. In this study, the United States FDA Adverse Event Reporting System (FAERS) was utilized to investigate immune-related adverse events linked with the use of atezolizumab. The study identified forty-nine immune-related adverse events that affected multiple organ systems, including cardiovascular, respiratory, hematologic, hepatic, renal, gastrointestinal, neurologic, musculoskeletal, dermatologic, endocrine, and systemic disorders. The strongest signals for relative risk occurred for immune-mediated encephalitis (RR = 93.443), autoimmune myocarditis (RR = 56.641), immune-mediated hepatitis (RR = 49.062), immune-mediated nephritis (RR = 40.947), and autoimmune arthritis (RR = 39.382). Despite the morbidity associated with these adverse events, emerging evidence suggests potential associations with improved survival outcomes. Overall, this report sheds light on the widespread immune-related adverse events that cause significant morbidity and mortality in patients with cancer being treated with atezolizumab and brings attention to them for the clinicians treating these patients.