Abstract: Objective To systematically characterize the potential drug toxicities of cemiplimab, a PD-1 inhibitor approved as an immune checkpoint inhibitor (ICI) in 2018 and used as an orphan drug for patients with metastatic or locally advanced cutaneous squamous cell carcinoma, in order to provide more evidence for subsequent ICIs immunotherapies. Methods Data was harvested from US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. Disproportionality analysis involving the information component (IC) and reporting odds ratio (ROR) was used to detect potential association between cemiplimab and adverse events (AEs). MedDRA software was used to code data on adverse events in FAERS database into a standardized terminology. Results A total of 10 051 679 records were extracted from the database, with 131 of them for cemiplimab. It was shown that toxicities were detected in cemiplimab, which included asthenia, back pain, decreased blood pressure, cytokine release syndrome, muscle spasms, neutropenia, pulmonary embolism, cellulitis, tumour inflammation and pyrexia. The proportion of such severe outcomes as death, life-threating conditions and disability in most of these AEs was quite high, which deserves more attention. Conclusion Toxicities have been detected in cemiplimab, and most of the outcomes of cemiplimab-related AEs are undesirable. Thus, it is important for clinicians to be alert to AEs in cemiplimab immunotherapies and take measures to prevent the occurrence of AEs so as to ensure the safety of patients.

Key words: immune checkpoint inhibitors, cemiplimab, drug-associated toxicities, FAERS database, disproportionality analysis