Long-term prophylaxis is recommended by international recommendations in patients with von Willebrand disease (VWD) with severe and regular bleeding. Researchers evaluated the effectiveness and safety of recombinant von Willebrand factor (rVWF; vonicog alfa) prophylaxis in patients with severe VWD since rVWF may lower the incidence of treated spontaneous bleeding events (BEs).
Patients with BEs who required the VWF therapy in the previous year (on-demand VWF therapy [prior on-demand group] or plasma-derived VWF prophylaxis [pdVWF; switch group]) were included in phase 3 prospective, open-label, nonrandomized research. The planned duration of rVWF prophylaxis was 12 months; the beginning rVWF dosage was 50±10 ristocetin cofactor (VWF:RCo) IU/kg twice weekly (prior on-demand group) or based on prior pdVWF weekly dose/dosing frequency (switch group).
The main motive of the study was the annualized bleeding rate (ABR) of treated spontaneous BEs (sABR) with rVWF prophylaxis. Over the course of the 12-month research, treatment sABR dropped by 91.5% on-study compared to historical sABR in 13 patients in the previous on-demand group and by 45.0% in 10 patients in the switch group (model-based analysis ratio, 0.085; 95% CI, 0.021-0.346 and 0.550; 95% CI, 0.086-3.523, respectively). There were no treated spontaneous BEs in 84.6% (11/13) and 70.0% (7/10) of patients, respectively. rVWF’s safety profile was similar to the previously reported profile, with no further adverse medication responses found.
The study’s findings suggested that rVWF prophylaxis could minimize treated spontaneous BEs in patients who earlier had on-demand VWF treatment and maintains at least the same degree of hemostatic control in patients who move from pdVWF to rVWF prophylaxis with a positive safety profile.