Efficacy predictors of omalizumab in Chinese patients with moderate-to-severe allergic asthma: Findings from a post-hoc analysis of a randomised phase III study()

BACKGROUND: Omalizumab has demonstrated efficacy as an add-on therapy in Chinese patients with moderate-to-severe allergic asthma. This post-hoc analysis assessed the potential predictors for the efficacy of omalizumab in these patients. METHODS: A post-hoc analysis was performed on a Phase III, randomised, controlled study conducted in Chinese patients with moderate-to-severe persistent allergic asthma (NCT01202903). We evaluated if levels of pre-treatment serum total immunoglobulin-E (IgE) and blood eosinophil (EOS), asthma severity, allergen profile, history of perennial allergic rhinitis (PAR), and free IgE level during omalizumab treatment were predictive of omalizumab's efficacy. RESULTS: This analysis included 608 patients (omalizumab, N = 306; placebo, N = 302). Improvements in forced expiratory volume in 1 s (FEV(1)), standardized Asthma Quality of Life Questionnaire (AQLQ), Asthma Control Questionnaire (ACQ), and Global Evaluation of Treatment Effectiveness (GETE) scores with omalizumab treatment compared with placebo were observed in patients with baseline IgE levels ≥76 IU/mL (irrespective of the EOS count). Relatively greater improvements with omalizumab treatment was also noted in patients with both moderate or severe allergic asthma (regardless of asthma severity), and patients sensitised to >3 allergens and with a history of PAR. All patients who were treated with omalizumab achieved free IgE levels below 50 ng/mL by Week 1. Similar clinical outcomes were observed in the subset of patients who achieved free IgE levels of <25 and ≥ 25 ng/mL. CONCLUSIONS: In Chinese patients with moderate-to-severe allergic asthma, baseline IgE and allergen profile (number/PAR history) are potential predictors of treatment response to omalizumab. TRIAL REGISTRATION: NCT01202903 (www.clinicaltrials.gov).