FDA Approves Topical for Rare Skin Disorder

The FDA has approved Filsuvez (birch triterpenes) for the treatment of partial thickness wounds in patients 6 months and older with junctional epidermolysis bullosa (JEB) and dystrophic epidermolysis bullosa (DEB).

Epidermolysis bullosa is a group of rare hereditary disorders of the skin, mucous membranes, and internal epithelial linings. It causes fragile and blistered skin. JEB causes blisters in the mouth and airway. DEB causes blisters in the middle layer of the skin. It affects about 1 out of every 20,000 births in the United States.

Filsuvez is a topical gel that was developed by Amryt Pharma, which was acquired by Chiesi Farmaceutici in April 2023. Filsuvez contains a dry extract from two species of birch bark consisting of naturally occurring substances known as triterpenes, which is thought to help the outer layer of the skin heal and close. It is the first approved treatment for wounds associated with JEB.

Filsuvez will be marketed by Chiesi Global Rare Diseases, a business unit of the Chiesi Group.

This approval was based on the positive phase 3 EASE trial results, which were published in the British Association of Dermatologists. This study enrolled 223 patients, with treated 109 treated with Filsuvez and 114 with a control gel. The study met the primary enpoint, with 41.3% of patients with first complete target wound closure within 45 days, compared with 28.9% in the control gel arm

Adverse events were predominantly of mild-to-moderate intensity. The most common reported adverse events were would complications. Serious adverse events were reported in 6.4% of patients treated with Filsuvez.

Filzuvez was approved by the European Medicines Agency (EMA) in June 202, for the treatment of partial-thickness wounds associated with DEB and JEB in patients six months and older.