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

Objectives: 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.

Methods: 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).

Results:  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).

Conclusions: 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.