Post marketing safety surveillance of atezolizumab based on a retrospective analysis of the FDA adverse events reporting system (FAERS)

Atezolizumab has been widely used for the immunotherapy of various cancers. This study aims to analyze the adverse events (AEs) associated with Atezolizumab post-marketing using the FDA Adverse Event Reporting System (FAERS). We conducted a retrospective analysis of the FAERS database, focusing on reports associated with atezolizumab from the first quarter of 2016 to the third quarter of 2024. The ADRs were stratified by demographics, event types, and reported outcomes. We performed a disproportionality analysis using the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the Bayesian confidence propagation neural network (BCPNN), and the empirical Bayesian geometric mean (EBGM) to assess the statistical association between atezolizumab use and specific AEs. Among the 18,310,937 non-duplicated reports collected from the FAERS database, 21,162 reports identified Atezolizumab as the "primary suspect (PS)," leading to the identification of 52,348 atezolizumab-induced AEs. The majority of AE reports (59.66%) occurred within the first 360 days of treatment, with most cases reported between 30 and 180 days of administration. A total of 494 Preferred Terms (PTs) were identified as significant across all four disproportionality-based pharmacovigilance signal assessment algorithms. The three system organ classes (SOCs) with the highest signal frequencies in AE reports were Gastrointestinal System Disorders (11.54%), Infectious and Invasive Disorders (10.12%), and Benign, Malignant, and Undetermined Tumors (including cystic and polypoid) (9.92%). The top five PTs with the strongest risk signals based on frequency screening were death, disease progression, pyrexia, anemia, and infectious pneumonia. Additionally, unexpected significant AEs were identified, including homicidal ideation, encephalitis, pancreatitis, disseminated intravascular coagulation, and Guillain- Barré syndrome. Atezolizumab treatment may be associated with a range of AEs. Further studies and continued pharmacovigilance efforts are essential to better understand the long-term safety of atezolizumab and to improve patient management strategies.