AstraZeneca Plc (LON:AZN), a global, science-led biopharmaceutical company, announced on Wednesday the grant by the US Food and Drug Administration (FDA) of Orphan Drug Designation (ODD) to Fasenra (benralizumab) for the treatment of hypereosinophilic syndrome (HES).

HES is a group of rare, potentially fatal disorders characterised by high numbers of eosinophils in blood and tissues, which can cause progressive damage to any organ in the body.

Reportedly, the FDA grants ODD status to medicines intended for the treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the US.

According to the company, a phase II clinical trial of Fasenra for the treatment of HES has been conducted by the US National Institutes of Health in collaboration with AstraZeneca, with results expected to be published later in 2019. In the trial, Fasenra depleted blood eosinophils at week 12 compared with placebo, the primary endpoint of the trial, with evidence of eosinophil clearance in affected tissue at week 24.3

Fasenra is AstraZeneca's first respiratory biologic and is currently approved as an add-on maintenance treatment for severe, eosinophilic asthma in the US, EU, Japan and several other countries. In November 2018, the FDA granted ODD for Fasenra for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA).

Fasenra was developed by AstraZeneca with MedImmune, the company's global biologics research and development arm, and is in-licensed from BioWa Inc, a wholly-owned subsidiary of Kyowa Hakko Kirin Co Ltd, Japan.

AstraZeneca is focused on the discovery, development and commercialisation of prescription medicines, primarily for the treatment of diseases in the three therapy areas of Oncology, Cardiovascular, Renal & Metabolism and Respiratory.