Pharmacokinetics, Efficacy and Safety of a Plasma-Derived VWF/FVIII Concentrate (Formulation V) in Pediatric Patients with von Willebrand Disease (SWIFTLY-VWD Study)

A Systematic Review of Efficacy and Safety of Plasma-Derived von Willebrand Factor/Factor VIII Concentrate (Voncento) in von Willebrand Disease

BACKGROUND

 For the treatment of von Willebrand disease (VWD), von Willebrand factor (VWF) concentrates can be used in on-demand, long-term prophylaxis, and surgical prophylaxis regimens.

METHODS

 This systematic literature review was conducted to evaluate the efficacy, consumption, and safety of plasma-derived human coagulation FVIII/human VWF (pdVWF/FVIII; Voncento/Biostate) for the treatment of patients with any inherited VWD type. An electronic search was conducted in MEDLINE and Cochrane Library databases on VWD therapies. All retrieved publications were assessed against predefined inclusion/exclusion criteria following the Cochrane group recommendations. Associated pharmacovigilance data were collected across the same time period.

RESULTS

 Eleven publications from eight study cohorts were identified for data retrieval. All were from multicenter studies and included both pediatric and adult patients. Eight publications included evaluations of the efficacy of pdVWF/FVIII for on-demand treatment, eight included long-term prophylactic treatment, and eight included surgical prophylaxis. Treatment protocols and VWF administration methods differed between studies, as did safety evaluations. The clinical response was rated as excellent/good for on-demand treatment in 66 to 100% of nonsurgical bleeds, 89 to 100% in the treatment of breakthrough bleeds during long-term prophylaxis treatment, and hemostatic efficacy in surgical procedures was 75 to 100%. Pharmacovigilance data confirmed a low incidence of adverse events in treated patients.

CONCLUSION

 This review provides a comprehensive summary of studies that evaluated the use of pdVWF/FVIII in VWD demonstrating the long-term effectiveness and safety of this pdVWF/FVIII across all ages, types of VWD, and treatment settings.

Efficacy and safety of von Willebrand factor concentrate almost devoid of factor VIII (Wilfactin®) in paediatric patients under 6 years of age with severe von Willebrand disease

BACKGROUND

Plasma-derived von Willebrand factor (VWF) (Wilfactin^®, LFB, France) was developed for prophylaxis and treatment of haemorrhages in both adults and adolescents with von Willebrand disease (VWD). Replacement therapy in paediatric patients is a key element of the clinical trial programme.

MATERIAL AND METHODS

Patients aged <6 years with severe VWD were enrolled in a multinational, open-label study to evaluate the in vivo recovery for Wilfactin^®, and its efficacy in preventing and treating bleeding episodes and during surgery. Overall haemostatic efficacy based on a 4-point scale was assessed by investigators. The treatment period ≥18 months investigated the long-term safety.

RESULTS

Nine patients, including 7 with type 3 VWD were exposed to treatment with Wilfactin^® for up to 4.2 years. Recovery of VWF in 7 patients (n=5 type 3, n=1 type 2, n=1 type 1) was 1.8±0.4 IU/dL per IU/kg. Of the 62 bleeds, 89% were controlled with one (73%) or two (16%) infusions of Wilfactin^®. The median dose per infusion was 54 IU/kg. A factor VIII dose was co-administered in 1.6% of bleeds. "Excellent"/"Good" haemostatic efficacy was achieved in 90.3% of episodes. Six patients underwent 11 minor surgical interventions. Treatment duration was 1 day (range: 1-6 days) with a dose administered 30-60 minutes before procedure of 56 IU/kg (range: 41-106 IU/kg). Haemostasis was rated as "Excellent" in all surgeries. During 4-year prophylactic treatment in one patient, breakthrough bleeds were reported in 2.2% of infusions. No VWF inhibitors, thromboembolic events or allergic/anaphylactic-type reactions were observed following a total exposure of 770 days.

DISCUSSION

The results show that Wilfactin^® provides a safe and effective treatment in patients <6 years of age with severe VWD.

Effectiveness of long-term prophylaxis using pdFVIII/VWF concentrate in patients with inherited von Willebrand disease

Background

Patients with symptomatic von Willebrand disease (VWD) should be offered long‐term prophylaxis (LTP) to prevent recurrent bleedings. Our objective was to evaluate the effectiveness and safety of Voncento®, a plasma‐derived FVIII/VWF concentrate (ratio 1:2.4), administrated in LTP.

Methods

We included patients from the OPALE study (May 2016 to April 2021), a French multicenter observational study following patients with inherited VWD, who received a Voncento® LTP during the study period.

Results

Among the 130 OPALE‐study patients, 23 patients (12 women) received a LTP and were therefore included. The median (range) age was 16 (1–85) years; 16 patients were type 3, 1 was type 2A, 6 were type 2B. Before inclusion, 19 (83%) were under LTP and 4 (17%) received on‐demand (OD) treatment. The indications for initiating prophylaxis in the overall population were joint bleeding (43%), ear, nose, and throat (ENT) bleeding including epistaxis or oral bleeding (39%), and recurrent muscle hematoma (22%). The medians (ranges) dose of Voncento® per infusion, frequency, and weekly dose were 45 (33–109) IU/kg, 2 infusions per week, and 96 (44–222) IU/kg/week, respectively. The median (range) annualized bleeding rate (ABR) was 0.8, 0.7 (0–3.5), and 0 (0–2.3) for type 2A, 2B, 3 patients, respectively. There was no difference regarding to the dose, frequency of infusion, or in terms of ABR in 9/19 patients who replaced previous concentrates with Voncento®. During the study period, no adverse event was reported.

Conclusion

These results suggest that Voncento® is effective to prevent recurrent bleedings in patients symptomatic VWD.

Prophylactic management of patients with von Willebrand disease

Von Willebrand disease, the most common inherited bleeding disorder that affects both males and females, is due to quantitative or qualitative defects of the multimeric glycoprotein von Willebrand factor, which cause mucous membrane bleeding but also soft tissue bleeding owing to the secondary deficiency of factor VIII. The aim of treatment is to correct this dual defect of hemostasis. In addition to the episodic management of bleeding episodes, therapy includes their short- or long-term prevention. Short-term prophylaxis is mainly warranted in order to provide effective hemostatic coverage to patients undergoing surgery or invasive procedures and to affected women at the time of delivery or during menstruations associated with excessive bleeding. The aim of long-term prophylaxis is to prevent bleeding in particular categories of patients at increased risk of frequent and spontaneous bleeding in the joints, nose, and gastrointestinal tract.

Translating the success of prophylaxis in haemophilia to von Willebrand disease

INTRODUCTION

There is limited awareness of von Willebrand disease (VWD), leading to challenges in both diagnosis and defining the optimal treatment approach for these patients. Patients with VWD are typically treated on-demand, with short-term prophylaxis used during surgery. In contrast, early initiation, and long-term use of prophylaxis is the standard of care in patients with severe haemophilia and can be successfully used to prevent joint bleeding and reduce chronic arthropathy.

AIM

To provide an understanding of the current evidence for the prophylactic treatment of patients with VWD and compare this to the management of patients with haemophilia.

METHODS

Review of published literature using a non-systematic search of PubMed and reference lists of sourced articles.

RESULTS

The successes seen with prophylaxis in haemophilia provide the rationale for long-term prophylaxis in patients with severe forms of VWD; preventing spontaneous, excessive and sometimes life-threatening bleeding, and reducing chronic joint disease. Currently, there are a few clinical trials assessing the long-term benefits of prophylaxis in VWD, and guidelines for the optimal prophylaxis treatment approach are lacking. Greater attempts to provide comprehensive, long-term care for patients with VWD are needed but still lacking within the community. This review highlights the success of prophylaxis in haemophilia and how this knowledge might be applied and translated to patients with VWD.

CONCLUSIONS

Lessons can be learned from the use of prophylaxis in haemophilia and prophylaxis should be considered the standard of care for a subgroup of patients with severe VWD.

An Open-Label Extension Study to Assess the Long-Term Efficacy and Safety of a Plasma-Derived von Willebrand Factor (VWF)/Factor VIII (FVIII) Concentrate in Patients with von Willebrand Disease (SWIFT-VWDext Study)

Objective

Plasma-derived von Willebrand factor/factor VIII (pdVWF/FVIII; VONCENTO^®, CSL Behring) is a high-concentration, low-volume, high-purity concentrate, which contains a high level of high-molecular-weight multimers and a VWF/FVIII ratio of ~2.4:1. The SWIFT ("Studies with von Willebrand factor/Factor VIII") program is evaluating pdVWF/FVIII in patients with von Willebrand disease (VWD). The long-term efficacy and safety profile of pdVWF/FVIII was investigated in this multicenter, open-label, extension study.

Methods

Pediatric, adolescent, and adult patients with VWD who required treatment of non-surgical bleeds (NSBs), treatment during surgical events or who were receiving prophylaxis and who had completed one of two previous clinical trials of pdVWF/FVIII were included. Efficacy and safety analyses were performed for on-demand (n=10), prophylaxis (n=8), or on-demand and prophylaxis (n=2) treatment in patients pre-treated with pdVWF/FVIII for ≥12 months.

Results

Seven patients experienced a total of 402 NSBs in the on-demand arm, of which 77 required treatment and nine NSB events in three patients were considered major. Nine patients reported 118 NSBs in the prophylaxis arm, with 96 events requiring treatment and seven patients experiencing 12 major NSB events. Excellent or good hemostatic efficacy was reported by the investigator for 98.7% (on-demand) and 97.9% (prophylaxis) of NSB events treated with pdVWF/FVIII, without relevant differences between subgroups by age. pdVWF/FVIII was well tolerated, and the adverse events seen were mild-moderate and consistent with the safety profile for this product seen in other studies. There were no cases of anaphylactic reactions and angioedema, development of VWF/FVIII inhibitors, thromboembolic events, or viral infections.

Conclusion

This contemporary comprehensive development program evaluating pdVWF/FVIII across all ages demonstrates long-term safety and efficacy for treatment and prevention of bleeds in patients with severe VWD, supporting the benefit-risk profile of pdVWF/FVIII.