Birch Bark Extract: A Review in Epidermolysis Bullosa

Abstract

Birch bark extract (Filsuvez^®; also known as the developmental name Oleogel-S10), a topical gel consisting of 10% dry birch bark extract and 90% sunflower oil, is the first therapy approved in the EU and UK for the treatment of partial thickness wounds associated with dystrophic and junctional epidermolysis bullosa (EB) in patients aged ≥ 6 months old. In the pivotal double-blind, randomized, vehicle-controlled, phase III EASE trial in patients with EB, the primary endpoint was met, in which birch bark extract relative to control gel significantly increased the proportion of patients with first complete target wound closure within 45 days. Moreover, patients treated with birch bark extract demonstrated several other positive findings in improving wound burden and wound-associated symptoms. The clinical benefits of birch bark extract were maintained in the 24-month open-label extension period of the EASE trial. Birch bark extract was generally well tolerated in patients with EB, with the tolerability profile being similar to that of control gel. Current evidence indicates that birch bark extract is an effective, emerging treatment option for patients with dystrophic and junctional EB.

Plain Language Summary

Epidermolysis bullosa (EB) is a rare, heterogenous genetic disorder characterized by extreme skin fragility and trauma-induced blister formation of the skin, mucosa or internal epithelial linings of organs. Due to lack of disease-modifying therapies, the mainstay treatment options for EB remain supportive in nature, such as wound care, skin protection, itch and pain management, infection control and trauma prevention. With various therapies being investigated as a potential treatment option for EB, birch bark extract (Filsuvez^®; also known as the developmental name Oleogel-S10) topical gel has been approved in the EU and UK for the treatment of partial thickness wounds associated with dystrophic and junctional EB in patients aged ≥ 6 months old. Birch bark extract has demonstrated anti-inflammatory, antibacterial, antiviral, antimycotic and wound-healing properties. In patients with EB, birch bark extract relative to control gel significantly accelerated wound healing within 45 days, together with other positive findings in improving wound burden and wound-associated symptoms. The clinical benefits of birch bark extract in improving wound burden were maintained for up to 24 months of continued treatment. Birch bark extract was generally well tolerated in patients with EB, with most adverse events being mild to moderate in severity. Current evidence indicates that birch bark extract is an effective, emerging treatment option for patients with dystrophic and junctional EB.