birch bark extract (Filsuvez)

Indication under review: treatment of partial thickness wounds associated with dystrophic and junctional epidermolysis bullosa (EB) in patients 6 months and older.

Key points:

• Epidermolysis bullosa (EB) is a heterogenous group of rare inherited skin disorders that is complex to manage and causes a substantial reduction in quality of life. It is characterised by very fragile skin that is prone to blistering and erosions due to minor trauma or friction, with the resulting wounds usually extending through multiple layers of the skin surface. As well as the high wound burden, there is impaired wound healing and debilitating symptoms such as pain, pruritis, scarring, deformity, and immobility. There are also several systemic complications (for example anaemia, increased risk of infections, osteoporosis, and squamous cell carcinoma). These all can carry considerable morbidity and increased mortality risk.
  
  
• In a double-blind, randomised, phase III study, birch bark extract gel led to quicker wound healing than a control gel. Results may also suggest potential improvements in the frequency of dressing changes, and the amount of affected skin.
  
  
• The effect of birch bark extract on other relevant outcomes (for example pain and itching) in patients with EB is unclear. There is uncertainty about whether the beneficial effects of birch bark extract gel that were observed in the recessive dystrophic EB (DEB) subgroup, which represented the majority of patients in the EASE study, will be translated to the other subtypes of EB (junctional EB [JEB] and dominant DEB).
  
  
• A model-based health economic evaluation indicates that birch extract is associated with improved quality of life. Modelling suggested that birch bark would generate a discounted incremental Quality Adjusted Life Year (QALY) gain of 1.02. However, there were uncertainties associated with the economic results as a result of the data and inputs employed as well as the assumptions used. Additionally, the treatment’s cost in relation to its health benefits is high.

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From 30 October, 2024, birch bark extract (Filsuvez) can be prescribed within the ultra-orphan pathway while further evidence on its effectiveness is generated. After 3 years the company will provide an updated submission for reassessment to allow a decision on its routine use in NHSScotland.