Abstract
BACKGROUND: Prophylaxis with a von Willebrand factor (VWF) concentrate is recommended in von Willebrand disease (VWD) patients with a history of frequent and severe bleeds. Despite nosebleeds being a frequent manifestation of VWD, few studies have investigated the efficacy of factor prophylaxis in preventing nosebleeds in patients with severe VWD. METHODS: This post-hoc analysis of a prospective, 12-month, phase 3 study assessed the efficacy of wilate in the prevention of nosebleeds in 33 patients aged ≥6 years with severe type 1, type 2 or type 3 VWD. All patients previously participated in a 6-month prospective study of on-demand treatment with any VWF concentrate. Prophylactic efficacy was assessed by comparing total and spontaneous annualized bleeding rates for nosebleeds (TABR and SABR, respectively) during prophylaxis with rates during on-demand treatment. RESULTS: The mean TABR and SABR for nosebleeds were reduced by 76% and 81% respectively during prophylaxis versus on-demand treatment (2.7 vs 11.0 and 2.1 vs 10.9). During the second 6 months of prophylaxis, mean TABR was 49% lower and mean SABR 57% lower versus the first 6 months. The percentage of patients with zero nosebleeds was 19% during 6 months of on-demand treatment, 55% during the first 6 months of prophylaxis, and 68% during the second 6 months of prophylaxis. The efficacy of wilate in the treatment of breakthrough nosebleeds was rated excellent in 99% of cases. CONCLUSION: This post-hoc analysis demonstrated the efficacy of wilate prophylaxis in the prevention and treatment of nosebleeds in children and adults with severe VWD.