Effectiveness of benralizumab in the Tokyo Asthma Study (TOAST): A real-world prospective interventional trial.

Background: Biologics are integral in the management of severe asthma. As the effectiveness of the anti-IL-5 receptor antibody benralizumab in Japan remains elusive, this study aimed to assess its real-world effectiveness in Japanese patients with severe asthma.
Methods: This prospective, interventional, single-arm clinical trial was conducted across ten facilities in Japan between September 2020 and July 2022. Adult patients with severe eosinophilic asthma (peripheral blood eosinophil count ≥150 cells/μl) were enrolled and treated with benralizumab. The primary endpoint was the change in ACQ-5 score from baseline to week 24.
Results: Of 103 patients, 98 (mean age: 62.1 years, women: 55.1 %, regular oral corticosteroids [OCS] treatment: 20.4 %) were included in the analysis. From baseline to week 24, benralizumab significantly improved ACQ-5 (-0.67, 95 % CI: -0.94 to -0.39) and AQLQ (0.71, 95 % CI: 0.46 to 0.96) scores with an increase in FEV1 (87 ml, 95 % CI: 15-159 ml). The maintenance OCS dose and the percentage of OCS users decreased from 13.9 mg/day to 6.0 mg/day and from 20.4 % to 9.2 %, respectively. Multivariable analysis identified baseline blood eosinophil count (≥400 cells/μl) and fractional exhaled nitric oxide (≥22 ppb) as independent predictors of therapeutic response to benralizumab. Benralizumab treatment was discontinued due to nonserious adverse events and patient choice in four and three patients, respectively.
Conclusions: In a real-world setting in Japan, patients with severe eosinophilic asthma treated with benralizumab demonstrated substantial improvements in asthma control, quality of life, and respiratory function with reduced OCS usage.
Trial Registration: Japan Registry of Clinical Trials (jRCTs031190237).
Competing Interests: Conflict of interest KM, MS, NH, YM, ET, MH, HN, HKab, JM, KF received honoraria for lectures from AstraZeneca. HN has received fee for advisory board from AstraZeneca. The rest of the authors have no conflict of interest.
(Copyright © 2024 Japanese Society of Allergology. Published by Elsevier B.V. All rights reserved.)