Fasenra

Fasenra. It is a monoclonal antibody medication used as an add-on maintenance treatment for severe eosinophilic asthma in patients aged 12 years and older. Developed by AstraZeneca, it works by directly targeting the interleukin-5 receptor alpha subunit (IL-5Rα) on eosinophils, leading to a rapid and near-complete depletion of these inflammatory cells from both the blood and tissue. Its approval and use represent a significant advancement in the precision treatment of severe asthma phenotypes.

Medical uses

Fasenra is indicated as an add-on maintenance treatment for patients with severe eosinophilic asthma, a phenotype characterized by elevated levels of eosinophils in the blood or sputum. Its use is supported by clinical trials such as the SIROCCO and CALIMA studies, which demonstrated its efficacy in reducing asthma exacerbations and improving lung function as measured by forced expiratory volume (FEV1). Treatment is typically initiated with a loading dose administered at the clinic, followed by regular subcutaneous injections that can be self-administered at home every eight weeks, offering a convenient dosing schedule compared to some other biologics.

Adverse effects

The most common adverse reactions associated with Fasenra include headache, pyrexia, and reactions at the injection site such as pain or erythema. As it causes rapid depletion of eosinophils, there is a theoretical increased risk of helminth infections, and patients with pre-existing parasitic infections should be treated prior to initiation. Clinical trials, including the ZONDA study, showed a generally favorable safety profile, with incidence of adverse events comparable to placebo. However, as with all monoclonal antibody therapies, there is a potential for hypersensitivity reactions, including anaphylaxis, though these events are reported infrequently.

Pharmacology

Fasenra is a humanized, afucosylated monoclonal antibody of the immunoglobulin G (IgG) class, specifically an IgG1 kappa isotype. Its mechanism of action involves high-affinity binding to the interleukin-5 receptor alpha subunit (IL-5Rα) expressed on the surface of eosinophils and basophils. This binding recruits natural killer cells via the antibody's Fc region, inducing antibody-dependent cell-mediated cytotoxicity (ADCC) and apoptosis. The afucosylation of the antibody enhances its affinity for the FcγRIIIa receptor on effector cells, potentiating this cytotoxic effect and leading to a rapid, near-total depletion of eosinophils from both peripheral circulation and tissue reservoirs like the airway.

History

The development of Fasenra, with the International Nonproprietary Name benralizumab, was spearheaded by AstraZeneca following its acquisition of the biotechnology company MedImmune. Its clinical development program included pivotal Phase III trials known as SIROCCO, CALIMA, and ZONDA, which investigated its efficacy in severe, uncontrolled asthma. Based on the positive results from these studies, the U.S. Food and Drug Administration (FDA) granted approval in November 2017, followed by the European Medicines Agency (EMA) in January 2018. Its approval marked it as the first respiratory biologic to demonstrate direct eosinophil depletion via ADCC.

Society and culture

Fasenra has been incorporated into major international treatment guidelines, including those from the Global Initiative for Asthma (GINA) and the European Respiratory Society (ERS)/American Thoracic Society (ATS). Its introduction has influenced the economic landscape of asthma care, prompting discussions on cost-effectiveness within health technology assessment bodies like the National Institute for Health and Care Excellence (NICE) in the United Kingdom. The drug has also been the subject of direct-to-consumer advertising campaigns by AstraZeneca in markets like the United States, raising its profile among patients and advocating for phenotype-driven treatment approaches in severe asthma.

Category:Monoclonal antibodies Category:Asthma medications Category:AstraZeneca