Efficacy and safety of a recombinant von Willebrand factor treatment in acquired von Willebrand syndrome in case of bleeding and surgical procedures.

Introduction: Acquired von Willebrand syndrome (AVWS) is a rare haemorrhagic disorder. The prophylaxis and treatment of bleeding before surgery are complex. Since 2018, a new recombinant VWF (rVWF) concentrate that contains no factor VIII (FVIII) but a high amount of high molecular weight VWF multimers has been available in France.

Aim: To describe the real-world experience of using rVWF in non-surgical bleeding and surgical procedures in patients with AVWS.

Methods: Fifteen bleeding episodes in seven patients and 16 surgeries in 10 patients were retrospectively analysed in t French haemostasis centres.

Results: During bleeding, the median number of infusions was only 1 (range 1-27) with a median loading dose of 58 IU/kg (range 17-116) rVWF and a total median dose of 65 IU/kg (range 35-1488) rVWF. Bleeding control was rated markedly effective in 73% (11/15) of the cases and ineffective in 27% (4/15). During surgeries, the median number of infusions was 3 (range 1-8) with a preoperative loading dose of 60 IU/kg (range 23-118) rVWF and a total median dose of 123 IU/kg (range 31-542). The overall clinical efficacy was qualified as excellent, good and poor (ISTH criteria) in respectively 7 (43%), 6 (38%) and 3 (19%) procedures. There was no accumulation of VWF or FVIII during postoperative monitoring. No thromboembolic events nor adverse events were reported.

Conclusion: This French 'real-world' experience shows that rVWF could be of interest in the treatment and prophylaxis of bleeding in patients with AVWS, with no clinically significant safety concern.