Comparative thrombotic event incidence after infusion of recombinant factor VIIa versus factor VIII inhibitor bypass activity.

Thromboembolic (TE) events are recognized but rare complications associated with the use of factor VIII inhibitor bypass activity (FEIBA) and rFVIIa. This study looks at the reported TE events of both products through thepharmacovigilance program of the FDA and published case reports between June 1999 and April 2002. Incidence of TE events were rare with both products, but more frequent with rFVIIa, especially cerebrovascular events, while cardiac events were more frequent with FEIBA. Information on associated risk factors is not available, and contrasting adverse events reporting patterns between rFVIIa and FEIBA as well as the larger number of patients receiving rFVIIa may have contributed to the observed difference in thrombotic event incidence, but superiority of safety of rFVIIa cannot be supported by these data.

– Maadh Aldouri