F8 and hemophilia B: The EHL FVIII concentrates have only marginal prolongation of FVIII half-life in the plasma, while EHL FIX concentrates demonstrate more substantial prolongations, allowing for weekly and even less frequent dosing intervals for those with hemophilia B. In 2023, a truly EHL product (antihemophilic factor [recombinant], Fc-VWF-XTEN [Sanofi Pharmaceuticals] fusion protein-ehtl) for use by people with hemophilia A received regulatory authorization allowing for weekly or less frequent dosing [33].