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

International audience ; 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.