Abstract
Background: In Canada nearly 8% of patients with asthma have severe disease. Benralizumab is an anti-IL-5Ra antagonist for add-on maintenance therapy of severe eosinophilic asthma.
Objective: To describe the change in asthma control and quality of life (QoL) in the first 8 weeks of benralizumab treatment.
Methods: POWER is a prospective observational study (NCT03833141) in 23 clinics across Canada from 2019 to current. Patients had blood eosinophils =300c/µL, Asthma Control Questionnaire (ACQ-6) score =1.5, and were benralizumab naïve. Early treatment response was assessed via patient-reported ACQ-6 at baseline and 1, 2, 4, and 8 weeks following first treatment. QoL was measured using Asthma Quality of Life Questionnaire (AQLQ) at baseline and week 8. Minimum clinically important difference in ACQ-6 and AQLQ is a change of 0.5 units.
Results: 80 patients had sufficient follow-up to for this interim analysis. The mean difference (MD; 95%CI) from baseline ACQ-6 score was -0.83 (-1.03, -0.63) at week 1, -0.99 (-1.19, -0.79) at week 2, -1.04 (-1.25,-0.83) at week 4, and -1.19 (-1.41,-0.96) at week 8 after initiation of treatment. At week 8, 31 (39%) and 9 (11%) patients achieved an ACQ-6 score of <1.5 (mean; 95%CI=0.87; 0.74,1.00) and <0.75 (0.44; 0.21,0.68), respectively. MD from baseline of AQLQ at 8 weeks was 1.23 (1.01,1.46).
Conclusions: Patients reported a significant and clinically meaningful difference in asthma control one week after first dose and 39% were partially or fully controlled before their third dose (ACQ-6 <1.5 at week 8). QoL improved similarly over the first 8 weeks of follow-up. These results show a rapid onset of benefit in patients initiating therapy with benralizumab.