Twice-Yearly Depemokimab in Severe Asthma with an Eosinophilic Phenotype

Depemokimab is an ultra-long-acting biologic therapy with enhanced binding affinity for interleukin-5 that may enable effective 6-month dosing intervals. In these phase 3A, randomized, placebo-controlled replicate trials, we evaluated the efficacy and safety of depemokimab in patients with severe asthma and an eosinophilic phenotype characterized by a high eosinophil count (≥300 cells per microliter in the previous 12 months or ≥150 cells per microliter at screening) and a history of exacerbations despite the receipt of medium- or high-dose inhaled glucocorticoids. Patients were randomly assigned in a 2:1 ratio to receive either depemokimab (at a dose of 100 mg subcutaneously) or placebo at weeks 0 and 26, plus standard care. The primary end point was the annualized rate of exacerbations at 52 weeks. Secondary end points, which were analyzed in a hierarchical manner to adjust for multiplicity, included the change from baseline in the score on the St. George's Respiratory Questionnaire (SGRQ), the forced expiratory volume in 1 second, and asthma symptom reports at 52 weeks. Across the two trials, 792 patients underwent randomization and 762 were included in the full analysis; 502 were assigned to receive depemokimab and 260 to receive placebo. The annualized rate of exacerbations was 0.46 (95% confidence interval [CI]), 0.36 to 0.58) with depemokimab and 1.11 (95% CI, 0.86 to 1.43) with placebo (rate ratio, 0.42; 95% CI, 0.30 to 0.59; P