Once-daily tiotropium Respimat® (tioR) add-on to at least ICS maintenance therapy has demonstrated asthma symptom control improvements in adults with moderate or severe symptomatic asthma, independent of serum IgE ≤ or >430μg/L (equivalent to 179.2 IU/L) and blood eosinophils ≤ or >0.6×109/L (equivalent to 600/μL), in conventional subgroup analyses. We assessed whether improvements in asthma control were observed in modeling estimates across a continuous range of IgE and eosinophil values following tioR add-on therapy.
Four Phase III double-blind, placebo-controlled, parallel-group trials: PrimoTinA-asthma® (2× 48-week trials; NCT00776984/NCT00772538; n=912) tioR 5µg or placebo Respimat® add-on to ICS (≥800μg budesonide or equivalent) + LABA; MezzoTinA-asthma® (2× 24-week trials; NCT01172808/NCT01172821; n=2100) tioR 5µg or 2.5µg or placebo add-on to ICS (400-800μg budesonide or equivalent). Patients had symptomatic asthma requiring at least ICS therapy for ≥4 weeks before screening; COPD was excluded. Seven-question Asthma Control Questionnaire (ACQ-7) score is the mean of questions scored using a Likert scale. Post hoc logistic regression modeling analyses of ACQ-7 responder rate (percentage of patients with minimally important reduction of ≥0.5) were performed across continuous ranges of IgE 2-2000μg/L and eosinophils 0.05-2.00×109/L following tioR therapy.
TioR consistently improved ACQ-7 responder rate, compared with placebo, across all IgE and eosinophil ranges (odds ratio >1), except tioR 2.5µg at the very lowest IgE and eosinophil values (MezzoTinA-asthma®).
Once-daily tiotropium Respimat® add-on to at least ICS improved asthma symptom control in patients with moderate or severe symptomatic asthma, across the range of IgE and eosinophil values, supporting findings from conventional subgroup analyses.