Antigenicity of activated recombinant factor VII followed through nine years of clinical experience.
Patients treated with activated recombinant factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) were followed for potential antibody formation. The recombinant product was used to control serious and mild-to-moderate bleeds in a hospital environment and mild-to-moderate bleeds at home. The 267 patients included 222 haemophilia A patients, 16 haemophilia B patients, 16 non-haemophilia patients with inhibitors, and 13 factor VII (FVII)-deficient patients. The individual exposure ranged from one to 121 episodes treated over a period of up to 6 years. Analysis for FVII antibodies in an immunoassay revealed that pre-treatment samples from 5% of the haemophilia A patients had values above the normal range. None of these reactions were specific. Increased post-treatment values were observed in two FVII-deficient patients; both patients had been previously treated with plasma-derived FVII. The FVII-specific antibodies reacted equally well with plasma FVII and rFVIIa. The overall result from antibody determination shows no indication of antibody formation against rFVIIa in haemophilia A or B patients or in non-haemophilia patients with acquired inhibitors; however, FVII-deficient patients represent a risk group for development of antibodies against FVII.
Nicolaisen
E M
EM
Vessel Wall Biology, Health Care Discovery, Novo Nordisk, Gentofte, Denmark. emn@novo.dk
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000941:Antigens / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005168:Factor VII Deficiency / Q000188:drug therapy*; D015942:Factor VIIa / Q000276:immunology / Q000627:therapeutic use*; D006467:Hemophilia A / Q000188:drug therapy*; D002836:Hemophilia B / Q000188:drug therapy*; D006470:Hemorrhage / Q000139:chemically induced / Q000276:immunology; D006801:Humans; D007223:Infant; D008875:Middle Aged; D011994:Recombinant Proteins / Q000276:immunology / Q000627:therapeutic use; D012189:Retrospective Studies; D012307:Risk Factors
D000941:Antigens; D011994:Recombinant Proteins; D015942:Factor VIIa