Background: Omalizumab is efficacious in the treatment of moderate-to-severe and severe persistent allergic (immunoglobulin E-mediated) asthma, reducing exacerbations, emergency visits and improving quality of life (QoL). However, as exacerbations are relatively infrequent, assessment of efficacy on day-to-day symptoms is warranted.
Aims: To investigate the effect of add-on omalizumab on day-to-day symptoms, and how they correlate with QoL in severe persistent asthma.
Methods: The correlation between asthma symptom scores and QoL [Asthma Quality of Life Questionnaire (AQLQ)] was assessed. Symptom-free days (total symptom score = 0) and symptom-controlled days (definition 1: total symptom score ≤1; and definition 2: morning peak expiratory flow ≥90% of baseline, daytime asthma score ≤1 and night-time asthma score = 0) were compared between the omalizumab-treated group, omalizumab responders and placebo.
Results: Four hundred and nineteen patients (omalizumab, n = 209; placebo, n = 210) were included in the efficacy analyses, and 61% (118/195) of patients with response data were classified as responders. Total symptom score strongly correlated with AQLQ overall and symptom scores and individual domains. AQLQ overall score correlated well with symptom scores. Responders had significantly more symptom-free days than the omalizumab-treated and placebo groups (45.8%, 37.2% and 22.6% respectively), and more symptom-controlled days (definition 1: 56.1%, 47.9% and 35.3%, respectively, and definition 2: 50.8%, 43.9% and 28.0%, respectively).
Conclusions: In patients with inadequately controlled severe persistent asthma, day-to-day symptoms correlate well with QoL. Add-on omalizumab significantly improves day-to-day symptoms compared with placebo. Further improvement in responders confirms the physician’s assessment as a response measure.