The use of recombinant factor VIIa in the treatment of bleeding disorders

Recombinant factor Vila was initially developed for the treatment of hemorrhagic episodes in hemophilic patients with inhibitors to factors VIII and IX. After its introduction, it has also been used "off-label" to enhance hemostasis in nonhemophilic patients who experience bleeding episodes not responsive to conventional therapy. Evidence so far indicates that the use of factor Vila in hemophilic patients with inhibitors is both safe and effective. Anecdotal reports also suggest that the product is safe and effective in controlling bleeding in nonhemophilic patients. However, its use in these conditions has not been approved by the FDA, and conclusive evidence of its effectiveness from controlled clinical trials is not yet available. Several questions pertaining to the use of factor Vila require further investigation, including the mechanism of action; the optimal dose; definitive indications; ultimate safety; and laboratory tests for monitoring therapy. (C) 2004 by The American Society of Hematology.