U.S. Factor XI Patients: Is There a Safer Treatment? Yes - Hemoleven.

Despite donor screening and newer PCR testing, human-derived fresh frozen plasma (FFP) is not without the potential for viral transmission. Factor XI-deficient patients are plentiful in the U.S. (estimate ~1500–2000). Although there is discordance between phenotype and genotype, with substantially fewer “bleeders” than those with deficiency, and spontaneous bleeding is rare, surgical intervention frequently demands replacement therapy. The English F XI concentrate, virally inactivated, had thrombosis as a complication, and heparin was added, but is no longer available in the U.S. An LFB factor XI concentrate (Hemoleven), doubly viral-inactivated, with heparin and ATIII is available internationally, but not in the U.S. A review of 56 cases treated in France, Spain, Switzerland, Canada, and Israel reveal that for minor and major surgery it is both safe and effective. Between 1992 and 2004, data for the use of Hemoleven for either prophylaxis, minor and major surgery was collected. In all, hemostasis was excellent. In three, concentrate was used because of anaphylaxis with FFP. Three had laboratory evidence of DIC and, of these, one had a PE. In addition, these three cases received excessive dosage. Twelve patients had recovery and half-life studies for this concentrate. T1/2 was 45.5 ± 7.9h and recovery was 1.85 ± 0.38%/u/kg. These data are evidence that a safer and effective therapy for F XI patients exist outside of the U.S. We should not have to wait for a new infectious agent transmitted by FFP before we make it available in the U.S.. We should have learned something from HIV, when DDAVP was used everywhere, but not licensed here.