Characterizing the post-market safety profile of cemiplimab: a pharmacovigilance study of the FDA adverse events reporting system database.

Cemiplimab is a fully human PD-1 inhibitor approved for cutaneous squamous cell carcinoma, basal cell carcinoma, and non-small cell lung cancer. Post-market safety surveillance is essential given the broad and evolving indications for immune checkpoint inhibitors. All FAERS reports with cemiplimab as the primary suspect drug were extracted. Proportional Reporting Ratios (PRR), Reporting Odds Ratios (ROR), and chi-squared statistics were calculated for each adverse event. Disproportionality signals were defined by PRR ≥ 2, chi-squared ≥ 3.841, and a minimum of 15 reports. A total of 1,460 cemiplimab reports were identified in the FAERS database. Twenty-two adverse events met all signal detection criteria. The strongest signals were observed for myocarditis (PRR 54.35, n = 40), myositis (PRR 46.10, n = 25), pemphigoid (PRR 36.06, n = 16), and pneumonitis (PRR 19.37, n = 31). Immune-mediated adverse events predominated, consistent with the mechanism of PD-1 blockade. FAERS disproportionality analysis identifies a signal profile for cemiplimab dominated by immune-related adverse events across cardiac, pulmonary, dermatologic, and endocrine systems. These findings are consistent with the known immunotoxicity of PD-1 inhibitors and support heightened clinical vigilance for myocarditis and immune-mediated pneumonitis.