How does fasenra help with severe asthma?

Fasenra contains benralizumab, a monoclonal antibody that targets interleukin-5 receptors on eosinophils. By binding these receptors it triggers natural killer cells to destroy the eosinophils, sharply reducing their numbers in blood and airway tissue.

How does the drop in eosinophils affect asthma symptoms?

Eosinophils release inflammatory proteins that damage airway walls and trigger bronchospasm. Lowering their count lessens this damage, cuts the frequency of asthma attacks, and improves lung function in patients whose disease is driven by eosinophilic inflammation.

Who is most likely to benefit from Fasenra?

The drug is approved for people aged 12 and older with severe eosinophilic asthma that remains uncontrolled despite high-dose inhaled corticosteroids plus long-acting beta agonists. Blood eosinophil counts above 150–300 cells/µL usually predict a stronger response.

How long does it take to see results?

Eosinophil counts fall within 24 hours after the first dose. Clinically meaningful reductions in exacerbations appear within the first four to eight weeks; lung-function gains can continue to build over the next several months.

What is the dosing schedule?

After three initial doses spaced four weeks apart, maintenance injections are given every eight weeks. The medication is delivered as a 30 mg subcutaneous injection, usually in the upper arm, thigh, or abdomen.

What side effects are patients asking about?

Common reactions include headache and sore throat. Injection-site reactions occur in a minority of users. Serious allergic reactions are rare but require immediate medical attention.

How does Fasenra compare with other biologics for severe asthma?

Unlike anti-IgE (Xolair) or anti-IL-4R (Dupixent) agents, Fasenra specifically depletes eosinophils rather than blocking IgE or broader cytokine signaling. Head-to-head data are limited, but real-world studies show broadly similar reductions in exacerbations across the three drug classes when patients are matched for their dominant inflammatory pathway.

When does the patent for Fasenra expire?

The composition-of-matter patent in the United States is scheduled to expire in 2028, with possible pediatric extensions into 2029. [1]