The US Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to Fasenra (benralizumab) for the treatment of eosinophilic oesophagitis (EoE), AstraZeneca has announced.

The treatment is AstraZeneca's first respiratory biologic medicine and is currently approved as an add-on maintenance treatment for severe, eosinophilic asthma in the US, EU, Japan and other countries.

Currently there are no FDA-approved treatments for EoE, but because Fasenra depletes eosinophils in blood and tissue, it could become a potential new medicine to treat patients with the rare disease.

Earlier this year a positive opinion was given by the European Medicines Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP) to add a self-administration option for the drug, and a new delivery method as a pre-filled, single-use auto-injector (the Fasenra pen).

It is also in development for severe nasal polyposis, eosinophilic oesophagitis, eosinophilic granulomatosis with polyangiitis, hypereosinophilic syndrome and chronic obstructive pulmonary disease.

Mene Pangalos, executive vice president, BioPharmaceuticals R&D, explained: “Eosinophilic oesophagitis is an allergic inflammatory disease that can affect children and adults, and typically patients experience a range of debilitating symptoms including severe pain and difficulty swallowing food.”

EoE is a rare, chronic, inflammatory disease of the oesophagus characterised by the accumulation of eosinophils, a type of white blood cell that are a normal part of the immune system, in the oesophageal lining tissue. The disease results in injury, fibrosis and dysfunction that if not effectively treated can make eating difficult or uncomfortable, potentially leading to chronic pain, difficulty swallowing, poor growth, malnutrition and weight loss.