Efficacy and safety of benralizumab in Japanese patients with severe, uncontrolled eosinophilic asthma

Background In the Phase III CALIMA trial, benralizumab significantly reduced asthma exacerbations, increased lung function, and alleviated symptoms for patients with severe, uncontrolled eosinophilic asthma. The aim of this subgroup analysis was to evaluate the efficacy and safety of benralizumab for Japanese patients in the CALIMA trial. Methods CALIMA was a randomised, controlled trial of 1306 patients (aged 12–75 years; registered at ClinicalTrials.gov: NCT01914757 ) with severe asthma uncontrolled by medium- to high-dosage inhaled corticosteroids and long-acting β 2 -agonists (ICS/LABA). Patients received 56 weeks' benralizumab 30 mg either every 4 weeks (Q4W) or every 8 weeks (Q8W; first three doses Q4W), or placebo Q4W. The primary analysis population was patients receiving high-dosage ICS/LABA with blood eosinophils ≥300 cells/μL. This subgroup analysis covered Japanese patients from this group. Results Of 83 patients randomised in Japan, 46 were receiving high-dosage ICS/LABA and had blood eosinophils ≥300 cells/μL. Compared with placebo, benralizumab reduced the annual rate of asthma exacerbations by 66% (Q4W; rate ratio 0.34, 95% CI, 0.11–0.99) and 83% (Q8W; rate ratio 0.17, 95% CI, 0.05–0.60); increased prebronchodilator FEV 1 by 0.334 L (Q4W; 95% CI, 0.020–0.647) and 0.198 L (Q8W; 95% CI, −0.118 to 0.514); and decreased total asthma symptom score by 0.17 (Q4W; 95% CI, −0.82 to 0.48) and 0.24 (Q8W; 95% CI, −0.87 to 0.40). Percentages of adverse events were consistent with the overall CALIMA group. Conclusions Benralizumab reduced annual asthma exacerbations and symptoms, increased lung function, and was well-tolerated by Japanese patients with severe, uncontrolled eosinophilic asthma.