Background: By 31 December 2022, the United States Food and Drug Administration (FDA) has approved 12 biosimilar monoclonal antibody cancer treatments. This study detected disproportionate adverse event (AE) reporting signals and compared safety profile of individual biosimilars to their originator biologics and between each pair of biosimilars.
Research design and methods: The FDA Adverse Event Reporting System data (6/1/2018-12/31/2022) were used to identify AE reports for rituximab, bevacizumab, trastuzumab, and their marketed biosimilars. Reporting odds ratios and empirical Bayesian geometric mean were computed to detect reporting disproportionality in serious, death, and specific AEs between studied biologics/biosimilars and all other drugs.
Results: Significant AE reporting signals were identified: 1) death for biological rituximab, pruritus for biosimilar rituximab-pvvr, and infusion-related reactions for biological rituximab and biosimilar rituximab-pvvr (significantly higher ROR for rituximab-pvvr than biological rituximab, p < .0001); 2) death for biological bevacizumab and biosimilar bevacizumab-bvzr (significantly higher ROR for bevacizumab-bvzr than biological bevacizumab, p < .0001), hypertension, platelet count decreased (PCD), and proteinuria for biological bevacizumab and biosimilar bevacizumab-awwb (significantly higher ROR of PCD for bevacizumab-awwb than originator bevacizumab, p = .001); and 3) rash for biosimilar trastuzumab-anns.
Conclusions: Findings call for large, longitudinal studies to examine causality of certain AEs with rituximab-pvvr and bevacizumab biosimilars.
Keywords: Biological monoclonal antibody; adverse events; bevacizumab; biosimilars; disproportionality analysis; pharmacovigilance; rituximab; trastuzumab.