Topline findings from the SWIFT trials
- Exdensur reduced annualized asthma exacerbations by 58% in SWIFT-1 and 48% in SWIFT-2 versus placebo at 52 weeks.
- A pooled analysis showed a 72% reduction in exacerbations requiring hospitalization or emergency care.
- Safety profiles were comparable between depemokimab and placebo, with no treatment-related serious adverse events or deaths.
- No significant differences were observed in SGRQ score changes between treatment groups.
- The therapy was administered twice yearly, supporting sustained IL-5 inhibition with fewer injections.
The FDA has approved GSK’s Exdensur (depemokimab-ulaa) for the treatment of severe asthma as an add-on maintenance therapy in adult and pediatric patients 12 years and older.1
Approval based on positive Phase III data in SWIFT trials
Exdensur’s approval is backed by findings from the SWIFT-1 (NCT04719832) and SWIFT-2 (NCT04718103) clinical trials, which both demonstrated significant reductions in annual asthma exacerbations.
In a company press release, 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.”
SWIFT trial outcomes
Results from the SWIFT trials are headlined by a 58% and 48% reduction in the rate of annualized asthma exacerbations over 52 weeks from SWIFT-1 and SWIFT-2, respectively. Additional findings include:2
- No significant between-group differences observed in St. George’s Respiratory Questionnaire (SGRQ) score changes.
- Adverse event (AE) rates were similar between depemokimab and placebo across both studies, with no treatment-related serious AEs or deaths.
- Depemokimab led to fewer exacerbations requiring hospitalization or emergency care compared with placebo in both trials.
- A pooled analysis showed a 72% reduction in clinically significant exacerbations requiring hospital or ED visits over 52 weeks versus placebo.
In a statement from when the SWIFT results were announced in May 2024, Khavandi said: “These results add to the established body of evidence that targeted inhibition of IL-5 plays a key role in reducing type 2 inflammation that drives severe asthma exacerbations. Depemokimab could offer the possibility of sustained inhibition of this pathway, with a dosing schedule of just two injections per year. This is important as research shows that 73% of physicians believe longer dosing intervals would be beneficial to patients who are often juggling multiple therapies.”3
According to GSK, depemokimab, an anti–interleukin (IL)-5 therapy, is the first ultra-long-acting biologic to be evaluated in Phase III trials to demonstrate a binding affinity and high potency for IL-5.
Trial design
SWIFT-1 and SWIFT-2 are replicate Phase IIIa, randomized, placebo-controlled trials in patients with severe eosinophilic asthma inadequately controlled on medium- or high-dose inhaled corticosteroids.
- A total of 792 patients were randomized 2:1 to receive depemokimab or placebo in addition to standard care.
- Depemokimab was administered subcutaneously at 100 mg at baseline and Week 26.
- The full analysis population included 762 patients (502 depemokimab; 260 placebo).
- The primary endpoint was annualized exacerbation rate at 52 weeks, with secondary endpoints including SGRQ score, lung function, and asthma symptoms.
Geoffrey Chupp, MD, Professor of Medicine, Pulmonary, Critical Care and Sleep Medicine, Yale University added: “Current biologic treatments for asthma are often underutilized 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 utilization. Exdensur could empower physicians and patients to potentially achieve their treatment goals with fewer injections.”
Additional depemokimab research
In addition to the SWIFT trials, GSK’s Phase III depemokimab program includes AGILE, an open-label extension study, as well as the ANCHOR-1 and ANCHOR-2 trials in chronic rhinosinusitis with nasal polyps.
Depemokimab is also being evaluated in eosinophilic granulomatosis with polyangiitis, hypereosinophilic syndrome, and chronic obstructive pulmonary disease.
References
1. Exdensur (depemokimab) approved by US FDA for the treatment of severe asthma. News release. GSK. December 16, 2025. Accessed December 17, 2025. https://www.gsk.com/en-gb/media/press-releases/exdensur-depemokimab-approved-by-us-fda-for-the-treatment-of-severe-asthma/
2. Phase III SWIFT Trials Show Ultra-Long-Acting Biologic Depemokimab Reduces Severe Asthma Exacerbations. Applied Clinical Trials. December 19, 2024. Accessed December 17, 2025. https://www.appliedclinicaltrialsonline.com/view/swift-trials-depemokimab-reduces-severe-asthma-exacerbations
3. GSK announces positive results from phase III severe asthma trials of depemokimab. News release. GSK. May 21, 2024. Accessed December 17, 2025. https://www.gsk.com/en-gb/media/press-releases/gsk-announces-positive-results-from-phase-iii-severe-asthma-trials-of-depemokimab/
