Prophylaxis with recombinant von Willebrand factor in patients with type 3 von Willebrand disease: Results of a post hoc analysis from a phase 3 trial
Frank W.G. Leebeek, Flora Peyvandi, Andreas Tiede, Giancarlo Castaman, Miguel A. Escobar, Michael Wang, Bülent Zülfikar, Sophie Susen, Wolfgang Miesbach, Scarlett Wang, Yi Wang, Jingmei Zhang, Gülden Özen
Abstract
OBJECTIVES: To describe efficacy/safety of recombinant von Willebrand factor (rVWF) prophylaxis in patients with type 3 von Willebrand disease (VWD). METHODS: This post hoc analysis of a phase 3 open-label trial provides a more detailed analysis of adults with type 3 VWD, categorized based on prior treatment at screening: "Prior On-Demand (OD)" (OD VWF; ≥3 documented spontaneous bleeding events [BEs] requiring VWF in previous 12 months) or "Switch" (plasma-derived [pd] VWF prophylaxis for ≥12 months). Annualized bleeding rates (ABRs) were evaluated during 12 months of rVWF prophylaxis versus historical data from medical records. RESULTS: In the Prior OD group (n = 10), mean spontaneous ABR (sABR) for treated BEs was reduced by 91.6% (ratio, 0.08; 95% CI, 0.02-0.45) versus mean historical sABR. In the Switch group (n = 8), mean sABR for treated BEs was reduced by 47% (ratio, 0.53; 95% CI, 0.08-3.62). One non-serious adverse event (AE) was considered possibly related to rVWF. No treatment-related, fatal, or life-threatening serious AEs were reported, and no patient developed VWF inhibitors. CONCLUSIONS: rVWF prophylaxis reduced sABR in type 3 VWD patients previously treated with OD VWF therapy, and maintained a similar level of hemostatic control in those switching from pdVWF prophylaxis to rVWF prophylaxis.