Safety of factor VIII inhibitor bypass activity (FEIBA^®): 10‐year compilation of thrombotic adverse events

Published and unpublished spontaneously reported thrombotic adverse events (AEs) in factor VIII inhibitor bypass activity (FEIBA(R)) recipients were compiled for the most recent 10-year period during which FEIBA(R) units equivalent to 3.95 x 105 typical infusions were distributed worldwide. A total of 16 thrombotic AEs were documented over the 10-year period, corresponding to an incidence of 4.05 per 105 infusions (95% CI, 2.32-6.58 per 105 infusions). Disseminated intravascular coagulation (n=7) and myocardial infarction (n=5) were the most frequent thrombotic AEs. One fatality occurred in an 87-year-old metastatic cancer patient. In 13/16 (81%) patients known risk factors were present, most commonly FEIBA(R) overdose in 8/16 (50%), obesity in 3/16 (19%) and serum lipid abnormalities in 2/16 (12%). These findings indicate that thrombotic AEs in FEIBA(R) recipients are very rare. Recognition of risk factors and avoidance of FEIBA(R) overdosage may avert thrombotic AEs.