RCT: Twice-Yearly Depemokimab Reduced Exacerbations in Severe Eosinophilic Asthma
17 Sep, 2024 | 22:39h | UTCBackground: Severe asthma with an eosinophilic phenotype often leads to frequent exacerbations despite treatment with medium- or high-dose inhaled glucocorticoids and additional controllers. Interleukin-5 is pivotal in eosinophil growth and survival, contributing to airway inflammation. Existing biologic therapies targeting interleukin-5 require frequent dosing intervals. Depemokimab is an ultra-long-acting anti–interleukin-5 biologic with enhanced binding affinity, potentially allowing effective dosing every six months.
Objective: To evaluate the efficacy and safety of twice-yearly depemokimab in reducing exacerbations in patients with severe eosinophilic asthma.
Methods: Two multicenter, randomized, double-blind, placebo-controlled phase 3A trials (SWIFT-1 and SWIFT-2) were conducted. Patients aged ≥12 years with severe asthma and an eosinophilic phenotype (blood eosinophil count ≥300 cells/μL in the previous 12 months or ≥150 cells/μL at screening) and at least two exacerbations in the prior year despite medium- or high-dose inhaled glucocorticoids plus another controller were enrolled. Participants were randomized 2:1 to receive depemokimab 100 mg or placebo subcutaneously at weeks 0 and 26, alongside standard care. The primary endpoint was the annualized rate of exacerbations over 52 weeks. Secondary endpoints included changes from baseline in the St. George’s Respiratory Questionnaire (SGRQ) score, prebronchodilator FEV₁, and asthma symptom scores at 52 weeks.
Results: A total of 792 patients were randomized, with 762 included in the full analysis set (502 depemokimab, 260 placebo). In SWIFT-1, depemokimab significantly reduced the annualized exacerbation rate compared to placebo (0.46 vs 1.11; rate ratio 0.42; 95% CI, 0.30–0.59; P < .001). Similar results were observed in SWIFT-2 (0.56 vs 1.08; rate ratio 0.52; 95% CI, 0.36–0.73; P < .001). No significant between-group differences were found in change from baseline in SGRQ scores. The incidence of adverse events was similar between groups in both trials.
Conclusions: Twice-yearly administration of depemokimab significantly reduced the annualized rate of exacerbations in patients with severe eosinophilic asthma.
Implications for Practice: Depemokimab administered every six months may offer an effective treatment option for reducing exacerbations in severe eosinophilic asthma, potentially enhancing patient adherence and reducing treatment burden associated with more frequent dosing schedules.
Study Strengths and Limitations: Strengths include large, multicenter, randomized, placebo-controlled design and replicate trials confirming efficacy. Limitations involve the lack of significant improvement in quality-of-life measures, low exacerbation rates in the placebo group, potential impact of the COVID-19 pandemic on trial conduct and outcomes, and limited data on certain subpopulations.
Future Research: Further studies are needed to assess long-term safety and efficacy, effects on quality-of-life measures, and the role of depemokimab in broader asthma populations, including those with varying eosinophil counts and biomarker profiles.