Disproportionality Analysis of Tirzepatide vs. Semaglutide and Liraglutide: System Organ Class-Level Post-Marketing Reporting Patterns in EudraVigilance.

Tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) receptor agonist, introduces a mechanistically distinct approach within incretin-based therapies. While its efficacy is established, real-world data comparing post-marketing safety with established GLP-1 receptor agonists remain limited. This study assessed System Organ Class (SOC)-level reporting patterns for tirzepatide versus semaglutide and liraglutide using EudraVigilance data. Aggregated individual case safety reports (ICSRs) were analyzed using pairwise disproportionality analyses based on a case/non-case approach. Reporting odds ratios (RORs) with 95% confidence intervals were calculated. False discovery rate (FDR) correction using the Benjamini-Hochberg procedure and sensitivity analyses restricted to serious and healthcare professional-reported cases were performed to assess robustness. After FDR adjustment, 20 SOCs were significant in tirzepatide-semaglutide and 23 in tirzepatide-liraglutide comparisons; eight SOCs remained significant across all analytical conditions. Compared with semaglutide, tirzepatide showed higher reporting for immune (ROR 1.97, 95% CI 1.75-2.21) and hepatobiliary disorders (ROR 1.71, 95% CI 1.61-1.82). Versus liraglutide, higher odds occurred for musculoskeletal (ROR 2.02, 95% CI 1.85-2.21) and psychiatric disorders (ROR 2.14, 95% CI 1.99-2.30), and lower odds for neoplasms (ROR 0.28, 95% CI 0.26-0.31). Tirzepatide shows heterogeneous reporting patterns compared with GLP-1 receptor agonists, with consistent excess reporting for hepatobiliary, immune, and musculoskeletal disorders. These findings are hypothesis-generating and warrant confirmation in exposure-adjusted studies.