Characterization of Severe Uncontrolled Asthma in Japan: Analysis of Baseline Data from the PROSPECT Study

PURPOSE: Treatment patterns and patient characteristics are not well elucidated among Japanese patients with severe uncontrolled asthma who currently have various treatment options, including biologics. We analyzed baseline characteristics of patients who did/did not initiate biologic treatment in PROSPECT, a 24-month observational study. PATIENTS AND METHODS: Patients with severe uncontrolled asthma were prospectively enrolled at 34 sites in Japan from December 2019 to September 2021. The enrolled population was divided based on initiation/non-initiation of biologic treatment within 12 weeks after enrollment. Patient demographics, clinical characteristics, biomarker levels, and asthma-related treatment were assessed at enrollment. RESULTS: Of 289 patients meeting the enrollment criteria, 127 patients initiated biologic treatment (BIO group: omalizumab, n = 16; mepolizumab, n = 10; benralizumab, n = 41; and dupilumab, n = 60) and 162 patients did not (non-BIO group). The proportion of patients with ≥2 asthma exacerbations was higher in the BIO group than the non-BIO group (65.0% vs 47.5%). Patients receiving omalizumab had the highest frequency of allergic rhinitis (87.5% vs other BIOs: 40.0%–53.3%). Patients receiving benralizumab and dupilumab had the highest incidence of nasal polyps (benralizumab: 19.5%, dupilumab: 23.3%, other BIOs: 0.0%). The proportion of patients with blood eosinophils ≥300 cells/μL was higher with benralizumab (75.6%) than other BIOs (26.7%–42.9%). CONCLUSION: This analysis of baseline data from the PROSPECT study is the first to clarify the characteristics of Japanese patients with severe uncontrolled asthma. BIOs were not necessarily prescribed to patients in whom they were indicated; however, for patients who received them, selection appeared to be made appropriately based on asthma phenotypes.