FDA grants Orphan Drug Designation to AZ’s hypereosinophilic syndrome drug

The FDA has granted Orphan Drug Designation to AstraZeneca’s Fasenra, a monoclonal antibody that binds directly to IL-5 receptor α on eosinophils and attracts natural killer cells to induce rapid and near-complete depletion of eosinophils via apoptosis. The drug has been developed for the treatment of hypereosinophilic syndrome, a group of rare disorders in which high numbers of eosinophils are found in the blood and tissue which can cause progressive organ damage over time, and can be fatal if not treated. A Phase II clinical trial of Fasenra was undertaken by AZ in partnership with the US National Institutes of Health, in which the drug was shown to deplete blood eosinophils at week 12 versus placebo, with evidence of eosinophil clearance in affected tissue at week 24.
EVP, R&D BioPharmaceuticals, Mene Pangalos, said: “In patients with hypereosinophilic syndrome, high levels of eosinophils contribute to a range of debilitating symptoms and can even lead to life-threatening organ damage. Based on results from the Phase II trial, we believe Fasenra has the potential to address critical unmet medical needs in patients living with hypereosinophilic syndrome.”