In early June 2021, Epidermolysis Bullosa News reported that Filsuvez (Oleogel-S10), a topical gel for epidermolysis bullosa (EB), received Priority Review designation from the FDA.

Filsuvez

Developed by Amryt Pharma, Filsuvez is a potential treatment for the subcutaneous manifestations of EB. According to a separate article published by Epidermolysis Bullosa News:

Filsuvez is a birch bark extract rich in betulin, which is thought to promote wound healing by controlling the inflammatory response and enhance the migration of keratinocytes — the main cell type of the outer layer of skin (epidermis).

Thus far, Filsuvez has been evaluated in clinical trials, such as the Phase 3 EASE trial. During the trial, 223 patients enrolled (156 pediatric patients and 67 adult patients). Patients had received a diagnosis of either Kindler syndrome, or junctional or dystrophic EB. Researchers determined that Filsuvez improved wound closure time and improved healing times.

Now, the FDA granted a Priority Review designation. This means that the FDA will take action on Amryt’s application within a 6 month period. According to the FDA:

A Priority Review designation will direct overall attention and resources to the evaluation of applications for drugs that, if approved, would be significant improvements in the safety or effectiveness of the treatment, diagnosis, or prevention of serious conditions when compared to standard applications.

Altogether, the company should have a final decision by November 30, 2021. Beyond Priority Review status, Filsuvez has also been granted Fast Track and Rare Pediatric Disease designations.

Epidermolysis Bullosa (EB)

Caused by KRT5 or KRT14 gene mutations, epidermolysis bullosa (EB) consists of a group of rare connective tissue diseases which cause fragile and blistering skin. Because the skin becomes so fragile, any form of rubbing or friction can cause moderate-to-severe blistering. In many cases, the blisters are only subcutaneous (external). However, in severe EB, blisters may also form internally in the respiratory system, stomach, esophagus, and more.

Altogether, there are three main forms of EB: junctional, dystrophic, and epidermolysis bullosa simplex. In the junctional form, the blisters are large, ulcerative, and can be life-threatening without medical assistance. Alternately, in the dystrophic form, patients have an increased risk of skin cancer.

Symptoms associated with EB include:

• Thick or abnormally formed nails
• Skin itching and/or pain
• Blisters in the mouth or throat
  • Note: This could also cause difficulty swallowing or breathing. If you or someone you know has EB and is having difficulty swallowing or breathing, please see your medical provider immediately.
• Fragile, easily blistered skin (especially on the hands and feet)
• Corneal abrasions
• Skin thickening, especially on the palms and soles
• Dental enamel defects
• Hair loss
• Scalp blistering and scarring
• Tiny white skin bumps or pimples (milia)
• Thin-appearing skin