Signal for Thrombosis with Eltrombopag and Romiplostim: A Disproportionality Analysis of Spontaneous Reports Within VigiBase registered

Eltrombopag and romiplostim are thrombopoietin receptor agonists (TPO-RA) marketed for immune thrombocytopenia. This study was aimed at assessing whether there is a signal for differential risks of thrombosis between these two TPO-RAs. The authors carried out a disproportionality analysis in the World Health Organization global individual case safety report (ICSR) database (VigiBase). They selected all ICSRs with exposure to a TPO-RA between January 2011 and December 2014. They identified 5,850 ICSRs, including 764 cases of thrombosis. In multivariate analyses, there was a signal for an increased risk of thrombosis, venous thrombosis, arterial thrombosis, ischaemic stroke and myocardial infarction with eltrombopag as compared with romiplostim. Restriction to ICSRs reported by physicians led to similar results. This study suggests the presence of a signal for an increased risk of thrombosis with eltrombopag compared with romiplostim. These results must be confirmed and quantified by large aetiological pharmacoepidemiological studies.