Effects of low-dose 'factor VIII inhibitor bypassing activity (FEIBA)' in resistant haemophilia.

Possible effects and side-effects of 'factor VIII inhibitor bypassing activity (FEIBA)' were tested on 7 haemophiliacs with high-titre antibody to factor VIII (resistant haemophilia). FEIBA was administered both to hospitalised patients and as part of a home therapy programme. Serious side-effects, attributable to FEIBA, were one episode of hypersensitivity and, possibly, hepatitis. Our preliminary data suggest that early injection of FEIBA, using considerably lower doses than suggested by the manufacturer, may shorten the duration of immobilisation of haemophiliacs with inhibitor against factor VIII in comparison with infusion of factor VIII and/or supportive care alone, at least following musculoskeletal bleeding. A decrease or complete disappearance of the inhibitor was observed in all patients receiving FEIBA alone.