The FVIII/FIX by-passing agent, rFVIIa, offers an alternative approach to the treatment of hemophilia patients as well as nonhemophiliacs with antibodies against FVIII/FIX. Such treatment can be administered regardless of the inhibitor titer in these patients, and rFVIIa is active hemostatically in hemophilia B patients also. It is easy to administer but seems to need repeated dosing at 2 to 3-hour intervals, at least initially, in patients with severe bleeding, with a dose of 70 to 100 micrograms/kg body weight required to induce hemostasis. Depending on the severity of the bleeding the dose intervals may be prolonged to every 3 hours for 1 to 2 days or until clinical improvement is observed. Thereafter, the dosage interval can be increased to every 4 hours if continued therapy is required.