[Production of factor VIII by genetic techniques].

The human factor VIII gene and the human von Willebrand factor gene have been isolated, and were transfected into a mammalian cell line (Chinese Hamster Ovary Cells = CHO Cells). The resulting factor VIII producing cell line was thoroughly characterized. No differences were found in the recombinant factor VIII compared to plasma-derived factor VIII. For factor VIII production the cells are grown in serum-free defined medium, the recombinant factor VIII is purified by immunoaffinity chromatography plus two subsequent ion exchange steps. The absence of human raw materials for production, and a proven titer reduction of > 10(7) in the purification process significantly minimize the risk of virus transmission by the recombinant factor VIII product. Clinical studies both with previously treated and untreated patients have proven the good hemostatic efficacy and virus safety of the recombinant factor VIII. The inhibitor incidence in previously untreated patients is within the expected range for this patient group.