Prospective, Single-Arm, Longitudinal Study of Biomarkers in Real-World Patients with Severe Asthma

BACKGROUND: ARIETTA was a prospective, single-arm, noninterventional, multicenter study in patients with severe asthma. OBJECTIVE: To examine the predictive and prognostic abilities of type 2 biomarkers for severe asthma outcomes. METHODS: Adult patients with severe asthma receiving daily inhaled corticosteroids (fluticasone propionate ≥500 μg or equivalent) and ≥1 second controller medication were enrolled. Biomarker, clinical, and safety data were collected over 52 weeks. The primary endpoint was the asthma exacerbation rate over 52 weeks in serum periostin-high (≥50 ng/mL at baseline) versus periostin-low subgroups (<50 ng/mL). Correlations between biomarker levels (periostin, blood eosinophils, IgE, and fractional exhaled nitric oxide [FeNO]) and between central and local laboratory measurements (blood eosinophils and IgE) were assessed. The study was terminated before planned enrollment was completed. RESULTS: Of 465 patients, 66.5% were female, 13.3% were receiving oral corticosteroids, 42.4% had ≥1 exacerbation in the previous year, 52.0% were periostin-high, and 87.5% had type 2 inflammation (blood eosinophils ≥150 cells/μL and/or FeNO ≥25 ppb and/or positive skin allergen test). Biomarker levels correlated poorly with each other. Central and local laboratory blood eosinophil and IgE measurements generally agreed. No difference was observed in exacerbation rates over 52 weeks between periostin-high and periostin-low patients (rate ratio, 0.93; 95% confidence interval, 0.67-1.28; P = .642). Results suggested higher exacerbation rates in patients with blood eosinophils ≥300 cells/μL and FeNO ≥25 ppb. CONCLUSIONS: No prognostic value for serum periostin related to exacerbations was detected. Higher blood eosinophils combined with increased FeNO were potentially associated with increased exacerbation rates.