Number of infusions required for resolution of 1796 hemorrhages.

A total of 2641 infusions were administered for on-demand treatment in 55 patients. The total number of infusions used to treat the site of any bleeding episode ranged from 1 to 123. The data exclude those from one patient after evidence of factor IX antibody was detected at month 9. Of the 2641 total infusions administered, 4% (101 of 2641) were at a dose of less than or equal to 20 IU/kg, 25% (663 of 2641) ranged from above 20 to 30 IU/kg, 18% (470 of 2641) ranged from above 30 to 40 IU/kg, 20% (537 of 2641) ranged from above 40 to 50 IU/kg, 15% (405 of 2641) ranged from above 50 to 60 IU/kg, and only 17% (461 of 2641) were used at doses above 60 IU/kg; the dose was not reported for 4 infusions. Thirty-three of the 56 PTPs used average doses for bleeding episodes and prophylaxis that were less than or equal to 50 IU/kg, whereas 23 used average doses of above 50 IU/kg. Twelve of these 23 patients used average doses between 50 and 60 IU/kg, 8 patients used average doses between 60 and 70 IU/kg, and 3 patients used higher average doses. The patient who used the far outlying average dose of 100.2 IU/kg is the patient who showed the lowest recovery in the PTP population at baseline (0.34 IU/dL per IU/kg rFIX given). The other 2 outlier patients used average doses between 70 to 80 IU/kg. One patient used self-determined doses (outside physician guidelines) and engaged in strenuous activity despite very severe hemophilic arthropathy. The other is the single PTP who developed a transient, low-titer inhibitor.