GSK secures FDA approval for Exdensur in severe eosinophilic asthma

GSK plc (LON:GSK, NYSE: GSK) has announced that the US Food and Drug Administration (FDA) has approved Exdensur (depemokimab-ulaa) as an add-on maintenance treatment of severe asthma characterised by an eosinophilic phenotype in adult and paediatric patients aged 12 years and older.

The FDA approval of Exdensur is based on data from the SWIFT-1 and SWIFT-2 phase III trials. In these studies, depemokimab demonstrated sustained exacerbation reduction with two doses per year versus placebo, both plus standard of care. Treatment with depemokimab resulted in a significant 58% and 48% reduction in the rate of annualised asthma exacerbations (asthma attacks) over 52 weeks from SWIFT-1 and SWIFT-2, respectively [rate ratio (95% confidence interval) p-value: SWIFT-1 0.42 (0.30, 0.59) p<0.001 and SWIFT-2 0.52 (0.36, 0.73) p<0.001] (AER depemokimab versus placebo: SWIFT-1 0.46 vs. 1.11 and SWIFT-2 0.56 vs. 1.08 exacerbations per year).¹

In a secondary endpoint from SWIFT-1 and SWIFT-2, patients treated with depemokimab experienced numerically fewer exacerbations requiring hospitalisation and/or emergency department visits (1% and 4%) compared with placebo (8% and 10%), respectively. A pre-specified pooled analysis of the two trials showed there was a 72% reduction in the annualised rate of clinically significant exacerbations requiring hospitalisation and/or ED visits over 52 weeks for depemokimab compared with placebo [rate ratio 0.28, 95% CI (0.13, 0.61), nominal p=0.002] (AER depemokimab 0.02 versus placebo 0.09). Across these trials, depemokimab was well-tolerated, with patients experiencing a similar rate and severity of side effects as those receiving placebo.¹

Kaivan Khavandi, SVP & Global Head, Respiratory, Immunology & Inflammation R&D, GSK said: “Physicians in the US now have the option to provide sustained protection from exacerbations for patients living with severe asthma with an eosinophilic phenotype in just two doses a year. Exdensur could redefine patient care and further establish the use of biologics for those who continue to experience exacerbations despite treatment.”

Depemokimab is a novel therapy that has been developed with an extended half-life, enabling the sustained suppression of disease-driving type 2 inflammation with twice-yearly dosing.¹ These distinct properties could potentially improve patient outcomes while reducing health system burden.

An estimated 2 million Americans live with severe asthma and half continue to experience frequent exacerbations that may lead to hospitalisations, emergency department visits and corresponding increased health system costs.^2,3,4 While biologics have demonstrated benefit in controlling severe asthma, only 20% of eligible patients in the US currently receive one, increasing their risk of exacerbations and worsening disease.⁵ Longer dosing intervals have been associated with an increased likelihood that patients would consider a biologic and 73% of physicians believe it would be beneficial.^6,7

Geoffrey Chupp, MD, Professor of Medicine, Pulmonary, Critical Care and Sleep Medicine, Yale University said: “Current biologic treatments for asthma are often underutilised and frequent injections can be inconvenient for many patients and lead to inconsistent use. There is clearly an opportunity to provide a longer duration of protection from exacerbations between injections for severe asthma patients that reduces the frequency of doses and may improve overall health care utilisation. Exdensur could empower physicians and patients to potentially achieve their treatment goals with fewer injections.”

Tonya Winders, President and CEO, Global Allergy & Airways Patient Platform said: “The struggle for people living with severe asthma is immense, with many silently enduring continued symptom recurrence and exacerbations. An innovative treatment option like Exdensur that offers the long-acting protection from exacerbations that severe asthma patients with an eosinophilic phenotype deserve, with the benefit of fewer doses, is truly welcome.”

Depemokimab recently received marketing authorisation from the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) and a positive CHMP opinion in Europe, with an approval decision expected in Q1 2026. Regulatory submissions are also under review across the globe, including in China and Japan.

References

1. Jackson, David J., et al. “Twice-yearly Depemokimab in severe asthma with an eosinophilic phenotype.” New England Journal of Medicine, vol. 391, no. 24, 19 Dec. 2024, pp. 2337-2349, https://doi.org/10.1056/nejmoa2406673.
2. Wang, Eileen, et al. “Characterization of severe asthma worldwide.” CHEST, vol. 157, no. 4, Apr. 2020, pp. 790-804, https://doi.org/10.1016/j.chest.2019.10.053.
3. Menzies-Gow, Andrew, et al. “A renewed charter: Key principles to improve patient care in severe asthma.” Advances in Therapy, vol. 39, no. 12, 17 Oct. 2022, pp. 5307-5326, https://doi.org/10.1007/s12325-022-02340-w.
4. “Cost of Asthma on Society.” Cost of Asthma on Society, Asthma & Allergy Foundation of America, 31 Jan. 2025, https://www.aafa.org/advocacy/key-issues/access-to-health-care/cost-of-asthma-on-society.
5. Park, Jihye, et al. “Unmet treatment needs in asthma patients with eosinophilic phenotype: A US claims-based study on asthma exacerbations and Healthcare Resource Utilization.” CHEST, vol. 166, no. 4, Oct. 2024, https://doi.org/10.1016/j.chest.2024.06.2816.
6. Tal-Singer, Ruth, et al. “Disease impact and perception of biologics in adults with type 2 inflammation respiratory disease: International survey results.” Patient Preference and Adherence, Volume 19, Apr. 2025, pp. 1159-1170, https://doi.org/10.2147/ppa.s517466.
7. Research Partnership Quant uptake Market Research, 200 HCPs Top two box on a seven-point scale where seven equaled “highly beneficial”.