Tiotropium Is Efficacious in 6- to 17-Year-Olds with Asthma, Independent of T2 Phenotype

Abstract

Background: Tiotropium add-on therapy has demonstrated efficacy and safety in 6- to 17-year-olds with symptomatic asthma despite treatment with inhaled corticosteroids (ICSs), with or without additional controllers. Pediatric patients often have a significant allergic component to their asthma.

Objective: To explore whether responses to tiotropium add-on were influenced by patients' type 2 status, assessed by serum IgE levels and blood eosinophil counts.

Methods: Data from 2 phase III trials in symptomatic moderate asthma (CanoTinA-asthma; RubaTinA-asthma) and 2 phase III trials in symptomatic severe asthma (VivaTinA-asthma; PensieTinA-asthma) were pooled by severity. Patients were treated with tiotropium 5 μg, tiotropium 2.5 μg, or placebo (2 puffs once daily via Respimat inhaler), as add-on to ICSs, with or without additional controllers. Modeling of efficacy outcomes was performed over the whole range of baseline IgE levels and blood eosinophil counts, and the treatment effect of the tiotropium doses was presented graphically.

Results: Improvements with tiotropium in peak FEV₁ within 3 hours postdose, trough FEV₁, forced expiratory flow at 25% to 75% of the pulmonary volume, and FEV₁/forced vital capacity responses were generally consistent across the range of baseline IgE levels and blood eosinophil counts. Risk of exacerbations and improvement in Asthma Control Questionnaire responder rates with tiotropium were also largely independent of IgE levels or eosinophil counts.

Conclusions: This exploratory analysis suggests that improvements with tiotropium as add-on to ICSs, with or without additional controllers, in 6- to 17-year-olds with symptomatic asthma do not vary according to systemic markers of T2 inflammation, namely, total IgE and blood eosinophil counts.

Keywords: Adolescents; Allergy; Asthma; Children; Eosinophil; IgE; T2 phenotype; Tiotropium Respimat.