Efficacy and safety of benralizumab for korean patients with severe, uncontrolled eosinophilic asthma

Purpose: In the Phase III SIROCCO trial (NCT01928771), benralizumab significantly reduced asthma exacerbations and improved lung function and symptoms for patients with severe, uncontrolled eosinophilic asthma. The aim of this subgroup analysis was to evaluate efficacy and safety of benralizumab for Korean patients in SIROCCO. Methods: SIROCCO was a randomized, double-blind, parallel-group, placebo-controlled trial of 1,204 patients aged 12-75 years with severe asthma uncontrolled by high-dosage inhaled corticosteroids/long-acting β2-agonists (ICS/LABA). Patients received benralizumab 30 mg every 4 weeks (Q4W) or every 8 weeks (Q8W; first 3 doses Q4W) or placebo Q4W for 48 weeks. The primary analysis population comprised patients with blood eosinophil counts ≥ 300 cells/μL. This subgroup analysis evaluated Korean patients from this group. Results: Of 122 Korean patients randomized, 86 had blood eosinophil counts ≥ 300 cells/μL. Benralizumab reduced the annual asthma exacerbation rate by 70% (Q4W: Rate estimate 0.79, rate ratio 0.30 [95% confidence interval {CI}, 0.13-0.65], nominal P = 0.003; n = 28) and 85% (Q8W: Rate estimate 0.40, rate ratio 0.15 [95% CI, 0.06-0.36], nominal P < 0.001; n = 30) vs. placebo (rate estimate 2.67, n = 28). Prebronchodilator forced expiratory volume in 1 second was increased with benralizumab treatment by 0.270 L (Q4W: 95% CI, 0.039-0.500, nominal P = 0.023; n = 28) and 0.362 L (Q8W: 95% CI, 0.143-0.582, nominal P = 0.002; n = 30) vs. placebo (n = 27). Total asthma symptom score was similar for patients receiving either benralizumab Q4W (-0.27 [95% CI, -0.83 to 0.30], nominal P = 0.356; n = 27) or benralizumab Q8W (0.10 [95% CI, -0.44 to 0.65], nominal P = 0.708; n = 30) vs. placebo (n = 28). Drug-related adverse events were experienced by 2%, 8%, and 5% of patients in the placebo, benralizumab Q4W, and benralizumab Q8W arms. Conclusions: Benralizumab reduced annual asthma exacerbation rates, increased lung function, and was well-tolerated by Korean patients with severe, uncontrolled eosinophilic asthma.