M. Johannessen et al., Decline of factor VIII and factor IX inhibitors during long-term treatmentwith NovoSeven (R), BL COAG FIB, 11(3), 2000, pp. 239-242
Recombinant factor VIIa (rFVIIa) (NovoSeven(R)) is used to treat bleeding e
pisodes in hemophilia A and B patients with inhibitor antibodies against fa
ctor VIII (FVIII) and factor IX. rFVIIa has been studied in home treatment
of mild-to-moderate joint, muscle, and mucocutaneous bleeds to assess safet
y and efficacy. Treatment with other factor concentrates was allowed accord
ing to treating physician's judgment. Blood samples were drawn before study
start and after 6 and 12 months. It has thus been possible to follow the i
nhibitor titres during this period. Analyses of 53 patients (49 hemophilia
A, four hemophilia B) showed inhibitor levels up to 1208 BU/ml before study
start. Based on the first analysis, hemophilia A patients were divided int
o high responders (> 5 BU/ml; 28 patients), low responders (> 1 and < 5 BU/
ml; 15 patients) and very low responders (less than or equal to 1 BU/ml; si
x patients). In high responders receiving rFVIIa as only treatment, FVIII i
nhibitor titre decreased to one-third of the initial level. For high respon
ders receiving other factor treatments such as FVIII or prothrombin complex
concentrates, inhibitor titre remained unchanged. Titres for low responder
s and very low responders remained unchanged independent of treatment. Thus
, when rFVIIa is used as the only coagulation factor to treat hemophilia A/
B high-responder inhibitor patients, inhibitor level declines significantly
. Blood Coagul Fibrinolysis 11:239-242 (C) 2000 Lippincott Williams & Wilki
ns.