Comparative analysis of adverse event reporting signals between Satralizumab and Inebilizumab in neuromyelitis optica spectrum disorder: A pharmacovigilance study using the FDA Adverse Event Reporting System

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disorder predominantly driven by anti-aquaporin-4 immunoglobulin G (AQP4-IgG), which mediates astrocyte injury, neuroinflammation, and demyelination. Satralizumab and Inebilizumab represent two promising therapeutic options with distinct mechanisms of action and clinical profiles. This study conducted a retrospective pharmacovigilance analysis of data from the U.S. FDA Adverse Event Reporting System (FAERS) from January 2020 to June 2025 to assess and compare adverse event (AE) reporting signals associated with Satralizumab and Inebilizumab. The analysis revealed a higher number of reported adverse events for Satralizumab compared to Inebilizumab (1,114 cases <i>vs.</i> 349 cases). A higher reporting proportion of AEs was observed in female patients for both drugs, with no statistically significant difference between them (exploratory <i>p</i> = 0.760). The reported AEs for both agents were primarily categorized under System Organ Classes (SOCs) such as infections and infestations and nervous system disorders. Urinary tract infection and pneumonia were among the most frequently reported preferred terms (PTs) for Satralizumab, whereas headache and COVID-19 were prominent for Inebilizumab. Reports classified as serious were more frequent for Satralizumab than for Inebilizumab (exploratory <i>p</i> < 0.01), noting that "seriousness" in FAERS may encompass outcomes related to underlying disease activity. This signal detection study highlights distinct adverse event reporting profiles for these biologics and offers insights that may inform clinical monitoring and personalized treatment strategies in NMOSD. Further studies with rigorous prospective designs are recommended to validate these findings and elucidate the mechanisms underlying the observed adverse events.