Recombinant factor IX (BeneFix®) by adjusted continuous infusion:: a study of stability, sterility and clinical experience

The safety and efficacy of adjusted continuous infusion (CI) of recombinant factor IX (FIX; BeneFix(R)) was assessed in vitro and in a clinical study. BeneFix(R) was reconstituted at 100 IU mL(-1) with or without unfractionated heparin (4 U mL(-1)) and stored at either 4 degreesC or room temperature. Reconstituted BeneFix(R) retained at least 90% activity over 14 days if stored at 4 degreesC but stability was reduced at room temperature. BeneFix(R) reconstituted in a sterile pharmacy was free of bacterial contamination. Six patients with haemophilia B received seven CIs of BeneFix(R) to cover routine surgery and severe bleeding episodes. The CIs lasted between 3 and 10 days. In all cases, haemostasis was excellent and the desired therapeutic FIX level was easily maintained. No thrombotic episodes or inhibitor development occurred but two patients developed thrombophlebitis at the infusion site when heparin was not added to the infusion. BeneFix(R) is not currently licensed for CT and we suggest that studies to enable licensing should be established as soon as possible.