Long-term Follow-up with Regard to Potential Immunogenicity: Clinical Experience with NovoSeven(recombinant Factor VIIa)

Twenty-eight patients were followed up for potential specific antibody formation after repeated use of recombinant factor VIIa (rFVIIa). The population included 27 patients with congenital bleeding disorders and 1 nonhemophiliac with an FVIII inhibitor. From 5 to 77 bleeding episodes were treated during a follow-up period of at least 5 months. None of these repeatedly treated patients showed signs of antibody formation against FVII or foreign protein that could be related to the treatment.