GLASGOW—Recombinant von Willebrand factor (rVWF) alone can be sufficient as perioperative management for some patients with severe von Willebrand disease (VWD), according to researchers.
In a phase 3 study, 10 of 15 patients were able to achieve hemostatic efficacy ratings of “good” or “excellent” when receiving only rVWF before, during, and/or after surgery.
The remaining 5 patients also achieved favorable hemostatic efficacy ratings, but they received recombinant factor VIII (FVIII) as well.
These results were presented at the World Federation of Hemophilia (WFH) 2018 World Congress (abstract W-MP-63 ). The research was sponsored by Shire, the company marketing rVWF as Vonvendi.
“There is an unmet clinical need for those living with von Willebrand disease, as they face a heightened risk of bleeding during surgery,” said study investigator Flora Peyvandi, MD, PhD, of the University of Milan in Italy.
“People with von Willebrand disease lack proper function or quantity of von Willebrand factor, and some also have a secondary factor VIII deficiency. In this study, recombinant von Willebrand factor was administered to replace the insufficient or dysfunctional von Willebrand factor, allowing the body to naturally replenish FVIII in most patients. These study results demonstrate clinical promise as physicians were able to tailor treatment based on each patient’s individual need for one or both factor therapies.”
The study included 15 adults with severe VWD who were undergoing elective surgical procedures. Ten patients were undergoing major surgery, 4 minor, and 1 oral surgery.
The patients’ median age was 40 (range, 20-70), and 8 were female. Most (n=8) had type 3 VWD, 3 had type 1, 2 had type 2A, 1 had 2B, and 1 had 2M.
At baseline, the mean endogenous FVIII level (FVIII:C) was 16.4 IU/dL, and the mean VWF ristocetin cofactor (VWF:Rco) was 10.6 IU/dL.
The patients received rVWF at 40 to 60 IU/kg VWF:RCo intravenously 12 to 24 hours before surgery to allow FVIII:C levels to increase to at least 30 IU/dL for minor or oral surgery or to at least 60 IU/dL for major surgery, within 3 hours before surgery.
If the desired levels were achieved, rVWF could be given alone. If the levels were not achieved, patients would receive rFVIII as well, within 1 to 2 hours before surgery. Patients were monitored for 14 days after surgery.
All 15 patients had overall/intraoperative hemostatic efficacy ratings of “excellent” (as good as or better than expected) or “good” (probably as good as expected).
The patients received a median of 6 (range, 2 to 15) rVWF infusions at a median dose of 55 IU/kg (range, 36.1 to 59.9). Most patients (n=11) did not receive rVWF every day. For some, infusions were separated by 2 to 9 days.
Ten patients received rVWF alone, 12 did not receive any preoperative FVIII, and 2 did not receive rVWF postoperatively.
Most rVWF infusions (89.4%, 93/104) were given alone, and 70% (7/10) of the major surgeries were performed with rVWF alone.
The researchers said that, with rVWF alone, patients had hemostatically effective levels of FVIII:C as early as 6 hours after surgery, and this was sustained for 72 to 96 hours.
There were 5 patients who received rVWF with rFVIII. Of the 11 infusions these patients received, 9 were given when FVIII:C levels were above 60 IU/dL.
Three patients received rVWF with rFVIII 1 hour before major surgery—total hip replacement, molar extraction, and left ankle prosthesis. However, 2 of these patients had FVIII:C levels above 60 IU/dL.
The patient undergoing a molar extraction received rVWF with rFVIII 6 times after surgery. In 5 cases, the patient’s FVIII:C levels were 110 to 152 IU/dL. In the remaining case, the FVIII:C level was 23 IU/dL.
Two patients received rVWF with rFVIII for minor surgery. One patient undergoing a tooth extraction received rVWF with rFVIII intraoperatively when the FVIII:C level was 72 IU/dL.
The other patient received rVWF with rFVIII after radioisotope synovectomy when the FVIII:C level was 73 IU/dL. This patient received a postoperative dose of rVWF alone as well.
One patient tested positive for binding antibodies to VWF, and 1 patient developed deep vein thrombosis 3 days after total hip replacement while receiving rVWF.