Shayla Bergmann, MD, Pediatric Hematologist/Oncologist at the Medical University of South Carolina, discusses phase 3 data of Vonvendi for the treatment of Von Willebrand disease (VWD).
VWD is a genetic condition caused by a missing or defective clotting protein [von Willebrand factor (VWF)] that binds to factor VIII. Symptoms and severity vary greatly. Common symptoms include nosebleeds, bruising, and excessive bleeding. In females, heavy menstrual bleeding is often what leads to a diagnosis. Acquired VWD may result from lymphoproliferative disorders, autoimmune disorders, heart conditions, increased blood platelet count, and certain drugs.
Vonvendi
Vonvendi [von Willebrand factor (Recombinant);rVWF] was approved by the U.S. Food and Drug Administration (FDA) in 2018 for the treatment of patients with VWD. In September 2025, the indication was expanded to include routine prophylaxis to reduce the frequency of bleeding episodes in adult patients, including those with Type 1 and 2 disease, and on-demand and perioperative management of bleeding in pediatric patients.
Phase 3 Data
New data from Phase 3 (NCT02932618) and phase 3b continuation (NCT03879135) studies evaluating the perioperative use of Vonvendi in pediatric patients with von Willebrand disease (VWD) was recently presented at the 2025 American Society of Hematology (ASH) Annual Meeting.
In this open-label, prospective, multicenter study, patients ages 17 years and younger with severe VWD were enrolled into one of three arms: on-demand treatment, elective surgery, or emergency surgery. After completing the Phase 3 study, participants could enter the Phase 3b continuation study, which also enrolled new non-rollover pediatric patients.
The interim analysis presented includes 8 pediatric patients who received rVWF for 9 minor surgical procedures. Overall perioperative hemostatic efficacy and intraoperative efficacy were rated “Excellent” for all 8 surgeries. Overall efficacy was missing for one minor surgery, for which the intraoperative efficacy rating was “Excellent”. The blood loss rating was also “Excellent” for 8 surgeries.
A total of 62 perioperative rVWF infusions were administered, with a median of 2.0 preoperative and 2.0 postoperative infusions of rVWF per surgery. The median preoperative rVWF dose was 79.4 IU/kg per surgery; the postoperative dose was 106.5 IU/kg per surgery. 75% of patients did not receive rFVIII for perioperative management. A total of 6 infusions of rFVIII were administered for two surgeries.
Four treatment-emergent adverse events were reported in three patients during the perioperative assessment period and included otitis media, viral upper respiratory tract infection, road traffic accident, and presyncope. None of these events were severe, serious, or fatal, or considered to be related to rVWF. No thromboembolic events or severe hypersensitivity reactions were reported, and no VWF or FVIII inhibitors were reported in either study.
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To learn more about VWD and other rare hematologic conditions, visit https://checkrare.com/diseases/hematologic-disorders/