FDA Approves Depemokimab as Add-On Maintenance Treatment in Severe Asthma

The FDA approved depemokimab-ulaa (Exdensur; GSK) as an add-on maintenance treatment for asthma in adult and pediatric patients aged 12 years and older with an eosinophilic phenotype.¹

Depemokimab is a monoclonal antibody that targets IL-5 and is the first ultra–long-acting biologic to be evaluated in phase 3 trials and be accepted for regulatory review for use in these conditions.² The agent’s extended half-life, high-binding affinity, and potency support 3-month (26-week) dosing regimens based on results from the SWIFT-1 (NCT04719832)³ and SWIFT-2 (NCT04718103)⁴ trials.^1,2

“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 utilization. [Depemokimab] could empower physicians and patients to potentially achieve their treatment goals with fewer injections,” Geoffrey Chupp, MD, professor of medicine, pulmonary, critical care and sleep medicine at Yale University, said in a news release.¹

Depemokimab’s Efficacy in Asthma: SWIFT-1 and SWIFT-2 Trials

SWIFT-1 and SWIFT-2 are randomized, placebo-controlled replicate phase 3a trials that were designed to evaluate the safety and efficacy of depemokimab in patients 12 years and older with severe asthma and an eosinophilic phenotype characterized by a high eosinophil count (≥300 cells/μL in the previous 12 months or ≥150 cells/μL at the time of screening) with a history of exacerbations despite receiving medium- or high-dose inhaled glucocorticoids. Across both trials, 762 patients (SWIFT-1: N = 382; SWIFT-2: N = 380) were randomly assigned to receive either depemokimab (n = 502) or a placebo (n = 260).^3-6

Overall, patients who were treated with depemokimab experienced a lower annualized rate of exacerbations at the 52-week point, with patients in both SWIFT-1 and SWIFT-2 having rates of about 0.46 (95% CI, 0.36, 0.58) and 0.56 (95% CI, 0.44, 0.70), respectively. The rates for placebo were about 1.11 (95% CI, 0.86, 1.43) and 1.08 (95% CI, 0.83, 1.41). In SWIFT-1, patients demonstrated a mean change from baseline in St. George Respiratory Questionnaire (SGRQ) score of –13.03 (95% CI, –15.22 to –10.84) and –9.67 (95% CI, –12.71 to –6.64) in the depemokimab and placebo groups, respectively. Mean changes in SWIFT-2 were about –14.80 (95% CI, –16.85 to –12.75) and –12.49 (95% CI, –15.36 to –9.63), respectively. Overall, there were no significant between-group differences in the change from baseline in SGRQ scores in either SWIFT trial; therefore, there was no statistical inference drawn on subsequent secondary end points.⁵

Recent data presented at the 2025 American College of Allergy, Asthma & Immunology Annual Scientific Meeting indicated that depemokimab was associated with greater improvements in least squares mean change from baseline in morning peak expiratory flow (PEF) compared with placebo from week 1 to 2 (18.08 [95% CI, 14.16, 22.01] vs 9.07 [95% CI, 3.65, 14.48] L/min, respectively), with an overall treatment difference of about 9.02 (95% CI, 2.31, 15.72). Improvement was sustained until weeks 51 to 52 (23.66 [95% CI, 17.64, 29.67] vs 7.81 [95% CI, 0.54, 16.16], respectively), with a treatment difference of about 15.84 (95% CI, 5.54, 26.15). Notably, change from baseline in nighttime awakenings and daily rescue medication use was numerically reduced from weeks 1 to 2 and maintained until weeks 51 to 52, according to the data.⁶

“The struggle for people living with severe asthma is immense, with many silently enduring continued symptom recurrence and exacerbations. An innovative treatment option like [depemokimab] 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,” Tonya Winders, president and CEO of the Global Allergy & Airways Patient Platform, said in the news release.¹

REFERENCES

1. GSK. Exdensur (depemokimab) approved by US FDA for the treatment of severe asthma. News release. 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. GSK. Depemokimab applications accepted for review by the US FDA for asthma with type 2 inflammation and for chronic rhinosinusitis with nasal polyps (CRSwNP). News release. March 3, 2025. Accessed December 16, 2025. https://www.gsk.com/en-gb/media/press-releases/depemokimab-applications-accepted-for-review-by-the-us-fda/

3. Placebo-controlled Efficacy and Safety Study of GSK3511294 (Depemokimab) in Participants With Severe Asthma With an Eosinophilic Phenotype (SWIFT-1). ClinicalTrials.gov identifier: NCT04719832. Updated December 17, 2024. Accessed December 16, 2025. https://clinicaltrials.gov/study/NCT04719832

4. A Study of GSK3511294 (Depemokimab) in Participants With Severe Asthma With an Eosinophilic Phenotype (SWIFT-2). ClinicalTrials.gov identifier: NCT04718103. Updated November 29, 2024. Accessed December 16, 2025. https://clinicaltrials.gov/study/NCT04718103

5. McGovern G. Depemokimab Every 6 Months Reduces Rate of Severe Asthma Exacerbations. Pharmacy Times. January 3, 2025. Accessed December 16, 2025. https://www.pharmacytimes.com/view/depemokimab-every-6-months-reduces-rate-of-severe-asthma-exacerbations

6. McGovern G. Twice-Yearly Depemokimab Improves Peak Expiratory Flow and Asthma Symptoms. Pharmacy Times. November 19, 2025. Accessed December 16, 2025. https://www.pharmacytimes.com/view/twice-yearly-depemokimab-improves-peak-expiratory-flow-and-asthma-symptoms