New respiratory biologic demonstrates significant improvement over prior steroid treatments.

AstraZeneca’s focus on biologics has led the company and its’ R&D arm, MedImmune, to another potential first-in-class treatment—this time for asthma. AstraZeneca announced the FDA had approved FASENRA™ (benralizumab) for the add-on maintenance treatment of patients aged 12 years and older, with severe asthma accompanied by the eosinophilic phenotype.

Severe, uncontrolled asthma, said AstraZeneca, is potentially fatal, debilitating patients through frequent exacerbations as well as limiting lung function and quality of life. Although AstraZeneca noted that FASENRA is not approved for the treatment of other eosinophilic conditions or relief of acute bronchospasm or status asthmaticus, it does represent a development in the treatment of the disease.

According to AstraZeneca, FASENRA binds directly to the IL-5α receptor on an eosinophil and attracts natural killer cells to induce apoptosis (programmed cell death). The treatment will be available to prescribing physicians as an injection, via a prefilled syringe. The biologic is intended to be administered once every four weeks for the first three doses, and then once every eight weeks after that.

FASENRA provides the near-complete depletion of eosinophils within 24 hours, as observed in the company’s Phase II study. Eosinophils are a type of white blood cell present as a normal element of the body's immune system. “Elevated levels of eosinophils, seen in about half of severe asthma patients, impact airway inflammation and airway hyper-responsiveness, resulting in increased asthma severity and symptoms, decreased lung function and increased risk of exacerbations,” said the company.

Trials revealed significant improvement including up to 51% reduction in the annual asthma exacerbation rate (AAER) versus placebo and improvement in lung function, as measured by forced expiratory volume in one second versus placebo. Differences, said the company, were seen as early as four weeks after the first dose, providing an early indication of effectiveness. Lastly, the trials observed a 75% median reduction in daily oral steroid use and its discontinuation in 52% of eligible patients.