Successful Tezepelumab Response and the Usefulness of Serum TARC Level as a Biomarker in a Severe Type 2 Bronchial Asthma Patient After Dupilumab, Mepolizumab, and Benralizumab Failure

Background: Treatment for severe type 2 bronchial asthma (BA) has advanced rapidly with the development of biologics. However, research on the responders and biomarkers for each biologic remains limited. Case Presentation: A 64-year-old female non-smoker with eosinophilic chronic rhinosinusitis and severe type 2 BA was administered dupilumab due to worsening nasal obstruction and olfactory impairment. Following this, the patient experienced secondary eosinophilia and worsening asthma control, necessitating frequent administration of systemic corticosteroids. Additionally, widespread maculopapular exanthema developed. Consequently, the treatment was switched to mepolizumab, which reduced blood eosinophil count; however, asthma control did not improve, and the maculopapular exanthema worsened, prompting another change to benralizumab. Due to persistent inadequate asthma control, the treatment was subsequently switched to tezepelumab, which resolved the maculopapular exanthema and decreased asthma exacerbations. Additionally, improvements in forced expiratory volume in one second and the asthma control test score were observed, along with a reduction in the serum thymus and activation-regulated chemokine (TARC) level. Conclusions: In some patients with severe type 2 BA who experience secondary eosinophilia and worsening asthma control after dupilumab administration, tezepelumab can be effective, and serum TARC levels could serve as a biomarker.