Post-Marketing Safety of Spinal Muscular Atrophy Therapies: Analysis of Spontaneous Adverse Drug Reactions from EudraVigilance.

Background/Objectives: Spinal muscular atrophy (SMA) treatment has evolved with the approval of nusinersen, onasemnogene abeparvovec, and risdiplam. This study aims to assess the post-marketing safety profile of these therapies through the spontaneous adverse drug reaction (ADR) reports available in EudraVigilance (EV). Methods: Data from EV were retrieved via adrreports.eu for the suspected ADRs associated with nusinersen, onasemnogene abeparvovec, and risdiplam from their approval in the European Economic Area (EEA) to 31 December 2024. The ADR reports were exported and analysed using descriptive statistics in Microsoft Excel. Reporting odds ratios (RORs) with 95% confidence intervals (CIs) were calculated for suspected ADRs, focusing on reactions with a lower limit of the 95% CI exceeding 1. Results: A total of 3196, 806, and 956 individual case safety reports (ICSRs) were identified for nusinersen, onasemnogene abeparvovec, and risdiplam, respectively. The most frequently reported ADRs with significantly increased RORs included post-lumbar puncture syndrome (nusinersen: 11%), pyrexia (onasemnogene abeparvovec: 23%), and pneumonia (risdiplam: 9%). While some ADRs were therapy-specific, others were consistent with SMA disease progression and complications. Onasemnogene abeparvovec showed a notable prevalence of hepatotoxicity, while risdiplam was associated with gastrointestinal and respiratory events. Conclusions: To conclude, the analysis reinforces the known safety profiles of these SMA treatments while highlighting potential areas for further investigation. ADRs related to SMA complications require careful differentiation from true drug-related effects. Future pharmacovigilance efforts should focus on long-term safety assessments and real-world evidence to optimize treatment strategies.