BACKGROUND
Biologics are an important treatment option for patients with severe asthma. Four biologics are available in Japan, and an overlapping eligibility has been observed. The eligibility and availability of drugs depend on the local regulations of different countries. However, there is no precise information about the eligibility for biologics, including dupilumab, in Japan. The aim of the study was to investigate the overlapping eligibility and to analyze the phenotypes of patients with multiple eligibility.
METHODS
In this observational study, a retrospective chart review of patients was performed. The eligibility criteria for omalizumab were IgE 30-1500IU/mL and positive IgE for perennial aeroallergen. The eligibility criteria for IL-5-targeted biologics (mepolizumab and benralizumab) were eosinophil counts (Eos) > 150μL, while those for dupilumab were Eos > 150μL or fraction of exhaled nitric oxide (FeNO) > 150ppb or IgE > 167IU/mL. Severe asthma was defined by the severity criteria under treatment based on Japanese guidelines for adult asthma.
RESULTS
One hundred patients with severe asthma were identified. The eligibility for omalizumab, IL-5-targeted therapies, and dupilumab was 43%, 69%, and 82%, respectively. Thirty percent of the patients were eligible for all the four biologics and showed the lowest FEV1, frequent exacerbation history, and the highest levels of Eos, FeNO, and serum periostin. Only 11% of the patients were not indicated for any biologics.
CONCLUSION
A considerable portion of patients was eligible for all the biologics. Asthma control was poor, and type 2 inflammation was prominent in such patients.