Outcomes of long-term von Willebrand factor prophylaxis use in von Willebrand disease: A systematic literature review

Background: Von Willebrand Disease (VWD) is a common inherited bleeding disorder. Patients with VWD suffering from severe bleeding may benefit from the use of secondary long-term prophylaxis. Aim: Systematically summarize the evidence on the clinical outcomes of secondary long-term prophylaxis in patients with VWD and severe recurrent bleedings. Methods: We searched Medline and EMBASE through October 2019 for relevant randomized clinical trials (RCTs) and comparative observational studies (OS) assessing the effects of secondary long-term prophylaxis in patients with VWD. We used Cochrane Risk of Bias (RoB) tool and the RoB for Non-Randomized Studies of interventions (ROBINS-I) tool to assess the quality of the included studies. We conducted random-effects meta-analyses and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Results: We included 12 studies. Evidence from one placebo controlled RCT suggested that VWD prophylaxis as compared to no prophylaxis reduced the rate of bleeding episodes (Rate ratio [RR],.24; 95% confidence interval [CI],.17–.35; low certainty evidence), and of epistaxis (RR,.38; 95%CI,.21–.67; moderate certainty evidence), and may increase serious adverse events RR 2.73 (95%CI.12–59.57; low certainty). Evidence from four before-and-after studies in which researchers reported comparative data suggested that VWD prophylaxis reduced the rate of bleeding (RR.34; 95%CI,.25–.46; very low certainty evidence). Conclusion: VWD prophylaxis treatment seems to reduce the risk of spontaneous bleeding, epistaxis, and hospitalizations. More RCTs should be conducted to increase the certainty in these benefits.