Benralizumab Reduces Exacerbations and Improves Lung Function in Patients From Republic of Korea With Severe, Uncontrolled Asthma: Subgroup Analysis of the SIROCCO Trial

RATIONALE: In the Phase III SIROCCO RCT (Lancet. 2016;388:2115–270), benralizumab significantly improved asthma exacerbations, lung function, and symptoms for patients with severe, uncontrolled eosinophilic asthma. This subanalysis evaluated benralizumab for patients from the Republic of Korea in SIROCCO.

METHODS: SIROCCO (N=1,204) included patients aged 12–75 years with severe asthma uncontrolled by high-dosage ICS/LABA. Patients received 48 weeks’ benralizumab 30 mg SC Q4W or Q8W (first three doses Q4W), or placebo. This analysis covered the patient subset from the Republic of Korea with baseline blood eosinophils ≥300 cells/µL.

RESULTS: Of 122 patients randomized, 86 had baseline blood eosinophils ≥300 cells/µL. Benralizumab reduced the annual asthma exacerbation rate by 70% (Q4W; marginal rate 0.90, rate ratio 0.30 [95% CI, 0.13–0.65], p=0.003; n=28) and 85% (Q8W; marginal rate 0.45, rate ratio 0.15 [95% CI, 0.06–0.36], p<0.001; n=30) vs. placebo (marginal rate 3.03; n=28); and increased prebronchodilator FEV₁ by 0.270 L (Q4W; 95% CI, 0.039–0.500, p=0.023; n=28) and 0.362 L (Q8W; 95% CI, 0.143–0.582, p=0.002; n=30) vs. placebo (n=27). There was no difference from placebo in total asthma symptom score for either regimen (Q4W: −0.28 [95% CI, −0.84 to 0.28, p=0.319; n=27]; Q8W: +0.07 [95% CI, −0.46 to 0.61, p=0.790; n=30] vs. placebo [n=28]). Adverse event rates approximated those of the overall SIROCCO population.

CONCLUSIONS: Benralizumab meaningfully reduced asthma exacerbations, improved lung function, and was generally well tolerated in patients with severe, eosinophilic asthma from the Republic of Korea. Symptom scores were more variable, which is likely related to small sample size.