A comparison between the adverse event profiles of patients receiving palbociclib and abemaciclib: analysis of two real-world databases

Abstract

Background: Palbociclib and abemaciclib are cyclin-dependent kinase (CDK) 4/6 inhibitors currently used to treat breast cancer. Although their therapeutic e cacies are considered comparable, differences of adverse event (AE) pro les between the two drugs remain unclear.Aim: We analysed two real-world databases, the World Health Organization's VigiBase and the Food and Drug Administration Adverse Event Reporting System (FAERS), to identify the differences in AE pro les between palbociclib and abemaciclib.Method: Data of patients with breast cancer receiving palbociclib or abemaciclib recorded until December 2022 were extracted from the VigiBase and FAERS databases. In total, 200 types of AEs were analysed. The reporting odds ratios were calculated using a disproportionality analysis.Results: Cytopenia was frequently reported in patients receiving palbociclib, while interstitial lung disease and diarrhoea were frequently reported in those receiving abemaciclib. Moreover, psychiatric and nervous system disorders were more common in the palbociclib group, whereas renal and urinary disorders were more common in the abemaciclib group. Conclusion:This study was the rst to show comprehensive disparities in the AE pro les between palbociclib and abemaciclib and highlighted the importance of considering these when selecting a suitable CDK4/6 inhibitor to ensure safe and favourable outcomes for patients with breast cancer. Impact statementsIn addition to cytopenia, many adverse events, including psychiatric and nervous system disorders, are potentially more frequent in patients receiving palbociclib compared to abemaciclib. Interstitial lung disease, diarrhoea, and renal and urinary disorders are potentially more frequent in patients receiving abemaciclib compared to palbociclib.The identi cation of adverse event pro les for palbociclib and abemaciclib contributes to drug selection that minimizes the risk of adverse events for individual patients.