Safety of Recombinant Activated Factor VII in Randomized Clinical Trials

Background The use of recombinant activated factor VII (rFVIIa) on an off-label basis to treat life-threatening bleeding has been associated with a perceived increased risk of thromboembolic complications. However, data from placebo-controlled trials are needed to properly assess the thromboembolic risk. To address this issue, we evaluated the rate of thromboembolic events in all published randomized, placebo-controlled trials of rFVIIa used on an off-label basis. Methods We analyzed data from 35 randomized clinical trials (26 studies involving patients and 9 studies involving healthy volunteers) to determine the frequency of thromboembolic events. The data were pooled with the use of random-effects models to calculate the odds ratios and 95% confidence intervals. Results Among 4468 subjects (4119 patients and 349 healthy volunteers), 401 had thromboembolic events (9.0%). Rates of arterial thromboembolic events among all 4468 subjects were higher among those who received rFVIIa than among those who receiv...