Association between cyclin-dependent kinase 4/6 inhibitors and venous thromboembolism: analysis of F.A.E.R.S. data

Real world studies have started to emerged on occurrence of venous thromboembolism (VTE) with cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, but still deserve constant surveillance and evaluation. This study was to analyze this association.Adverse event cases were acquired from the US Food and Drug Administration Adverse Event Reporting System (FAERS) database betweenJanuary 1st 2015 and December 31st 2020.Signals indicating association between CDK 4/6 inhibitors and VTE were identified by reporting odds ratio (ROR). CDK 4/6 inhibitors had a total of 631 reports of VTE (ROR 1.44, 95% CI 1.33-1.55) compared with non-CDK 4/6 inhibitors. Palbociclib (ROR 1.42, 95% CI 1.09-1.88) demonstratedthe highest number of VTE reports, followed by ribociclib (ROR 1.41, 95% CI 1.29-1.54) and abemaciclib (ROR 0.92, 95% CI 0.72-1.17).Although it is not able to confirm the casual relationship between VTE and CDK4/6 inhibitors, this study suggested signal of VTE reporting in patients receiving CDK4/6 inhibitors, which is likely to reflect a potential association. The results may enhance physicians' awareness of the potential side effect of VTE associated with CDK 4/6 inhibitors. An early recognition of VTE signs/symptoms could decrease the morbidity and severity of such adverse events.