| アブストラクト | ICI-induced inflammatory myositis (IIM) is a recognized irAE with significant morbidity and potential for life-threatening overlap syndromes. Whether polymyositis (PM) and dermatomyositis (DM) carry differential pharmacovigilance signals across ICI drug classes has not been systematically examined. A disproportionality analysis of FAERS was conducted to quantify reporting odds ratios across twelve approved ICI agents. Adverse event reports were extracted from FAERS through March 2026 using OpenVigil 2.1. RORs with 95% CIs were calculated for twelve ICI agents spanning PD-1, PD-L1, CTLA-4, and LAG-3 classes. Primary MedDRA endpoints were myositis, immune-mediated myositis, polymyositis, and dermatomyositis. Significant disproportionality for broad myositis was identified across all adequately powered ICI agents (PD-1, PD-L1, CTLA-4, LAG-3 classes), with RORs ranging 12- to 47-fold above background. The largest adequately powered signals were observed for pembrolizumab (ROR 18.34, n = 258), nivolumab (ROR 18.65, n = 256), atezolizumab (ROR 22.22, n = 132), and ipilimumab (ROR 15.11, n = 73); cemiplimab (ROR 46.89), relatlimab (ROR 44.68), and dostarlimab (ROR 33.48) produced high-magnitude estimates with smaller case counts. The immune-mediated myositis Preferred Term generated the largest estimates: pembrolizumab (ROR 45.64, n = 187), nivolumab (ROR 33.11, n = 137), and ipilimumab (ROR 25.40, n = 38). Significant dermatomyositis signals were identified in five agents, with atezolizumab producing the largest powered estimate (ROR 15.53, n = 29); DM RORs consistently exceeded PM RORs across agents, though ascertainment and coding bias likely contribute to this pattern. IIM is a pharmacovigilance signal of substantial magnitude across all ICI drug classes. The DM phenotype is more consistently disproportionate than PM across classes, with mechanistic plausibility given PD-L1's role in restraining interferon-producing plasmacytoid dendritic cells. The immune-mediated myositis MedDRA term captures the most statistically robust signal, reflecting a distinct ICI-associated coding pattern in spontaneous reporting. |
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