von Willebrand patients see major drop in bleeds with Wilate use in trial
Preventive treatment cuts bleeding rates by over 80% for those with type 3
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Preventive (prophylactic) treatment with Wilate reduced annual bleeding rates by more than 80% in people with von Willebrand disease (VWD) type 3, the most severe form of the bleeding disorder, according to new data from a small but global clinical trial.
Data also showed that spontaneous bleeds — those occurring without injury — were reduced by nearly 90%, with episodes requiring treatment dropping by more than 90%.
Benefits were consistent across age groups and seen for children, adolescents, and adults. The therapy was generally safe and well tolerated, the data also showed.
These findings come from a subgroup analysis of the Phase 3 WIL-31 study (NCT04052698), which evaluated the effectiveness and safety of Wilate as a prophylaxis, or preventive therapy, in people with the three main types of VWD. The trial involved individuals with VWD types 1, 2, and 3 who had previously received on-demand treatment with other replacement therapies.
“Prophylaxis with wilate was effective and well tolerated in patients with type 3 VWD, in all age groups,” the researchers wrote, adding that “this analysis provides much needed evidence for the efficacy and safety of prophylaxis in this [patient] population.”
The study, “Efficacy and Safety of Prophylaxis With a Plasma-Derived von Willebrand Factor/Factor VIII Concentrate (Wilate) in Patients With Type 3 von Willebrand Disease — A WIL-31 Study Sub-Analysis,” was published in the European Journal of Haematology. The study was supported by Octapharma, the company marketing Wilate.
Type 3 VWD is the rarest and usually the most severe form of VWD, a bleeding disorder marked by a deficiency of a clotting protein called von Willebrand factor (VWF). Without enough working VWF, patients can experience frequent and excessive bleeding episodes.
Treatment for VWD often involves replacement therapies that supply the body with a working version of the VWF protein. These can be given on demand to treat bleeds or regularly as prophylactic therapy to reduce bleeding frequency. Wilate is one such therapy, providing VWF together with another clotting protein called factor VIII (FVIII).
The therapy is given intravenously, or into the vein.
Little data on effects of preventive treatment in VWD type 3
Despite people with type 3 VWD often having the greatest need for effective long-term treatment to manage bleeding symptoms, “there is limited evidence showing the safety and efficacy of prophylaxis with VWF in [these] patients,” the researchers wrote.
To address this gap, an international team of scientists analyzed data from 22 people with type 3 VWD enrolled in the WIL-31 study. In that trial, completed in 2022, participants received prophylactic treatment with Wilate 2-3 times per week for one year after a prior period of on-demand treatment with VWF-containing products. Outcomes during prophylaxis were compared with those from the earlier on-demand treatment period.
Nearly two-thirds of the participants were male. Five patients (23%) were children, four (18%) were adolescents, and 13 (59%) were adults.
Over the year on Wilate, 19 participants (86%) experienced a total of 115 bleeds, the data showed. The most common sites were the nose (40%) and mouth (30%). Spontaneous bleeds accounted for 55% of events, while 41% were linked to injury and 4% had no clear cause.
Slightly more than half of the bleeds (55%) required treatment, and most of those — about 90% — were controlled with one or two additional infusions of Wilate, according to the researchers. One patient required a red blood cell transfusion.
Wilate use reduced spontaneous bleeds by nearly 90%
The analysis found that bleeding rates were significantly lower while the participants were on prophylaxis compared with the prior on-demand period. Before starting preventive treatment, patients had a mean of 37.1 bleeds per year, which fell to 5.2 bleeds per year on prophylactic Wilate — an 86% reduction, the data showed.
Spontaneous bleeds dropped from 26.5 to 2.8 per year, an 89% reduction, while spontaneous bleeds that required treatment fell by 93%. More than one-third of patients (36%) had no spontaneous bleeds at all during the year on Wilate.
Similar reductions in both total and spontaneous bleeding were seen across all patient groups, meaning children, adolescents, and adults all saw benefits.
Prophylaxis [preventive treatment] with wilate was efficacious [produced the desired effect] and well-tolerated in patients with type 3 VWD, with substantial reductions observed in bleeding rates compared with prior on-demand treatment.
Joint bleeds, a major cause of long-term complications, also were reduced with Wilate use. Mean joint bleeds dropped from 10 per year during on-demand treatment to 0.8 per year on prophylaxis. That was a drop of 92%. Further, all previously identified target joints, meaning joints with repeated bleeds, resolved by the end of the study.
Treatment was generally safe and well tolerated. A total of 52 adverse events were reported in 18 patients, including two that were classified as serious, but none were considered related to Wilate. No clot-related complications nor allergic reactions were observed. No participants developed inhibitors, or antibodies, against VWF or FVIII. No adverse events led to treatment discontinuation.
“Prophylaxis with wilate was efficacious and well-tolerated in patients with type 3 VWD, with substantial reductions observed in bleeding rates compared with prior on-demand treatment,” the researchers concluded, noting also that the “results were consistent across age groups.”
