VPB1190 - Efmoroctocog alfa and invasive procedures in patients with hemophilia A

Background: Efmoroctocog alfa (rFVIIIFc) is an extended half-life FVIII.

Aims: We report herein our experience in managing 70 surgeries in patients with hemophilia A (HA), using rFVIIIFc.

Methods: Patients with HA followed at the Lyon Comprehensive Hemophilia Care Center who underwent a surgery with rFVIIIFc were included in this retrospective analysis. Considering the large variability in pharmacokinetics (PK), patients underwent a preoperative PK evaluation. Plasma factor VIII clotting activity (FVIII:C) was evaluated using both one-stage (FVIII:Cos) and chromogenic (FVIII:Cch) assays for preoperative-PK and daily monitoring of FVIII:C during the post-operative period. The results were compared using Mann Whitney U test and p< 0.05 was considered statistically significant.

Results: 39 major surgeries and 31 minor surgeries were performed in 49 patients (33 severe, 2 moderate and 14 mild HA). The preoperative dose of rFVIIIFc was 66.1±16.5 IU/kg (mean±SD) and 45.5±7.4 IU/kg, for major and minor surgeries respectively. An additional infusion of rFVIIIFc 28.04±1.62 IU/kg was administered 12 hours after the first infusion in 8 major surgeries.
During the first postoperative week, the rFVIIIFc consumption was 38.95±10.29 IU/kg/day with a total of 6.51±1.68 rFVIIIFc infusions per major surgery, whilst it was 3.06±1.86 infusions per minor surgery with a rFVIIIFc consumption of 36.01±11.20 IU/kg/day (p=0.03). When available, the peroperative blood loss was estimated at 310.34±350.76 mL for major surgeries. No red blood cell transfusions were required in none of the surgeries.
During the postoperative period, rFVIIIFc doses were adjusted according to FVIII:Cch results. According to our local guideline, we compared rFVIIIFc consumption when dosages are calculated based on the chromogenic and one-stage-FVIII:C assays. Using FVIII:Cch, rFVIIIFc consumption is decreased compared to FVIII:Cos. Considering the high cost of the molecule, the use of FVIII:Cch in our patients was associated with cost saving.

Conclusion(s): rFVIIIFc is effective, safe and well tolerated in patients with HA undergoing invasive procedures.