Weight-based Dosing in Hemophilia A

The investigators propose a single center, randomized, controlled, open-label, crossover trial to determine if recombinant factor VIII (rFVIII) dosed according to lean body mass (LBM) and ideal body weight (IBW) achieves a targeted FVIII recovery with better precision than based on total body weight (TBW). The investigators hypothesize the use of LBM and IBW to determine the dose of rFVIII necessary to attain a desired FVIII recovery of 2 +/- 0.2 IU/dl per IU/kg (100 +/- 10%) in overweight and obese (body mass index greater than or equal to 25 mg/m2), adult males (age 18 or older) with hemophilia A (FVIII activity 40% or less) will result in a 50% greater proportion of subjects within this range when compared to TBW. Eligible patients receiving care at the Hemophilia Center of Western Pennsylvania (HCWP) will be enrolled during clinic visits. Following enrollment and completion of screening assessment, subjects will present to HCWP for three study visits with each study visit occurring on successive weeks. Subjects will not have received any rFVIII for a period of at least 72 hours prior to each study visit. Recombinant FVIII infusion based on TBW, LBM, or IBW will take place during each study visit, and the order will be determined by randomization. During each study visit, FVIII levels will be assessed by obtaining blood samples before and at 10 and 30 minutes and 1 hour after infusion. Outcomes include the proportion of subjects achieving a desired peak FVIII recovery value of 2 +/- 0.2 IU/dl per IU/kg (100 +/- 10%) at 10 minutes following infusion of rFVIII dosed according to LBM and TBW, IBW and TBW, and LBM and IBW. The investigators will use mixed effects logistic regression to investigate the effect of using different weight-based dosing methods on attaining target FVIII levels. We aim to have 24 subjects successfully complete the study.