Individualizing dosing frequency may improve the efficacy of prophylaxis in patients with von Willebrand disease-a...

The efficacy and safety of prophylaxis with wilate, a plasma-derived von Willebrand factor/factor VIII concentrate, was demonstrated in patients with von Willebrand disease of all types in the WIL-31 study.

To investigate the reasons for and the impact of changing the dosing frequency during WIL-31.

Patients received 20 to 40 IU/kg wilate 2 or 3 times weekly for 12 months. Bleeding rates were analyzed in patients who changed dosing regimen during the study.

Of 33 patients in WIL-31, 30 (91%) initiated prophylaxis 2 times weekly. Of these, 7 (21%) patients increased to 3 times weekly dosing during the study. Four (57%) had underlying circumstances leading to the regimen change: undiagnosed gingivitis, multiple comorbidities, severe menarche, and ongoing left/right ankle arthropathy. The median total annualized bleeding rate in these 7 patients improved from 60.6 during on-demand treatment to 24.0 on 2 times weekly (60.4% reduction) and 3.8 on 3 times weekly prophylaxis (overall reduction, 93.7%). The median spontaneous annualized bleeding rate improved from 32.2 during on-demand treatment to 5.8 on 2 times weekly (82.0% reduction) and 2.4 on 3 times weekly prophylaxis (overall reduction, 92.5%). Despite increased dosing, no von Willebrand factor or FVIII accumulation or thrombotic events were observed.

In the WIL-31 study, a small proportion of patients increased the frequency of prophylaxis, which resulted in effective prevention of bleeding. In most cases, there were underlying medical conditions that necessitated the increased dosing frequency, indicating that personalization of prophylaxis may be beneficial in patients with von Willebrand disease.

NCT04052698; https://clinicaltrials.gov/study/NCT04052698.