Class-Specific Adverse Events of Patients Treated with Small Interfering RNA Therapeutics: A Disproportionality Analysis of the United States Food and Drug Administration Adverse Event Reporting System Database Based on the MY FAERS Platform

Small interfering RNA (siRNA) therapeutics represent a transformative class of drugs, but their class-specific adverse events (CAE-siRNA) remain incompletely characterized. This study aimed to identify and quantify CAE-siRNA associated with U.S. Food and Drug Administration (FDA)-approved siRNA drugs (patisiran, givosiran, vutrisiran, inclisiran, and lumasiran) using real-world pharmacovigilance data, focusing on potential class-wide effects. A disproportionality analysis was conducted using the FDA Adverse Event Reporting System database (2014-2025Q2) accessed via the MY FAERS platform. The reporting odds ratio (ROR) with 95% confidence interval (CI) was calculated, with signals defined by a lower CI >1 and ≥3 cases. Sensitivity analyses included indication-matched populations (IMPs) and exclusion of concomitant medications. Causality was assessed using Bradford Hill criteria. Among 6200 siRNA-treated patients, 45 CAE-siRNA spanning 10 system organ classes were identified. Pain and pain in extremity, fatigue, and gastrointestinal disorders were the most frequently reported. Notably, patisiran was associated with an elevated risk of back pain (ROR: 2.28, 95% CI: 1.84-2.83), whereas givosiran exhibited significant signals for stress (ROR: 5.29, 95% CI: 3.64-7.70) and weight loss (ROR: 2.35, 95% CI: 1.74-3.16). Of particular concern, inclisiran demonstrated strong hepatic toxicity signals (ROR ranging from 9.11 to 86.06) along with discomfort (ROR: 3.60, 95% CI: 1.34-9.65). Sensitivity analyses confirmed robustness across subgroups. Furthermore, causality assessment supported a likely association between the hepatic toxicity and inclisiran. This study identified clinically relevant CAE-siRNA, particularly hepatic toxicity for inclisiran, supporting enhanced monitoring. While disproportionality analyses are hypothesis generating, these findings underscore the need for targeted pharmacovigilance to optimize the safety of this promising drug class.