GSK has received U.S. Food and Drug Administration approval for Exdensur (depemokimab-ulaa), a new add-on maintenance treatment for patients aged 12 years and older with severe asthma characterised by an eosinophilic phenotype. The approval introduces a biologic therapy that requires just two doses per year, a dosing schedule that could significantly change how severe asthma is managed in the United States.
The FDA decision is based on results from the Phase III SWIFT-1 and SWIFT-2 clinical trials, which evaluated depemokimab in patients whose asthma remained uncontrolled despite standard of care. Across both studies, Exdensur demonstrated a sustained and clinically meaningful reduction in asthma exacerbations over a 52-week period compared with placebo. Patients treated with depemokimab experienced a 58% reduction in annualised asthma exacerbations in SWIFT-1 and a 48% reduction in SWIFT-2, with both results achieving strong statistical significance.
In absolute terms, patients receiving depemokimab had fewer than one exacerbation per year on average, compared with just over one exacerbation per year in the placebo groups. These findings highlight the therapy’s ability to provide long-lasting protection against asthma attacks, a key goal in the management of severe disease.
Additional analyses from the trials suggested further benefits. In secondary endpoints, patients treated with depemokimab experienced fewer exacerbations requiring hospitalisation or emergency department visits compared with placebo. A pooled analysis of SWIFT-1 and SWIFT-2 showed a 72% reduction in the annualised rate of clinically significant exacerbations requiring hospital or emergency care. Such outcomes point to the potential for Exdensur not only to improve patient health but also to reduce pressure on healthcare systems.
Safety results were also encouraging. Across both Phase III trials, depemokimab was generally well tolerated, with rates and severity of side effects similar to those observed in patients receiving placebo. No new safety concerns were identified, supporting its suitability as a long-term maintenance therapy.
Depemokimab is designed with an extended half-life, enabling sustained suppression of type 2 inflammation, a key driver of eosinophilic asthma. GSK believes this pharmacological profile allows for effective disease control with twice-yearly dosing, potentially improving adherence compared with biologics that require more frequent injections.
Severe asthma remains a major unmet medical need in the United States. An estimated two million Americans live with severe asthma, and around half continue to experience frequent exacerbations that can lead to hospitalisation and emergency department visits. Although biologic therapies have proven effective, uptake remains limited, with only about one in five eligible patients currently receiving such treatments. Experts note that less frequent dosing could encourage broader adoption among both patients and physicians.
Clinicians and patient advocates have welcomed the approval. Respiratory specialists point out that frequent injections can be inconvenient and contribute to inconsistent use of existing biologics. A therapy like Exdensur, which offers prolonged protection with fewer injections, may help patients achieve better disease control while simplifying long-term management.
The FDA approval follows recent regulatory momentum for depemokimab globally. The therapy has already received marketing authorisation from the UK’s Medicines and Healthcare products Regulatory Agency and a positive opinion from the European Medicines Agency’s CHMP, with a final European decision expected in early 2026. Regulatory reviews are also ongoing in markets including China and Japan.
With Exdensur, GSK aims to redefine biologic treatment for severe eosinophilic asthma by combining strong efficacy with a patient-friendly dosing schedule, addressing both clinical outcomes and real-world treatment challenges.