Background: The Epidemiologic Study of Xolair (omalizumab): Evaluating Clinical Effectiveness and Long-term Safety in Patients with Moderate-to-Severe Asthma (EXCELS) is a unique opportunity to evaluate the prospective, long-term clinical safety and effectiveness of the anti-IgE antibody omalizumab (Xolair) in real-world clinical practice.
Objectives: To describe the study design and study cohorts of EXCELS at baseline and to compare the characteristics of this population with other large asthma cohorts.
Methods: Patients with moderate-to-severe persistent asthma and a positive skin test result or in vitro reactivity to a perennial aeroallergen were eligible for EXCELS. Two cohorts of patients with asthma were enrolled: those treated with omalizumab and those not treated with omalizumab. We analyzed baseline demographic and clinical characteristics, including asthma history and control and allergy history.
Results: Large proportions of patients enrolled in EXCELS had historically severe and poorly or not well-controlled asthma at the time of enrollment, objective evidence of airway obstruction, a history of long-term oral corticosteroid use, and/or other allergic disorders. Minor differences were observed between the omalizumab and nonomalizumab cohorts. Our total patient cohort was generally similar to other large cohorts. In a subgroup analysis, patients who had received omalizumab within 7 days before enrollment had more severe asthma and greater degrees of impairment at baseline than nonomalizumab patients.
Conclusions: This study of baseline characteristics in EXCELS offers a unique opportunity to better understand the history of allergic patients with moderate-to-severe asthma in a real-world treatment setting. This analysis of EXCELS baseline data sets the foundation for long-term assessment of the safety and effectiveness of omalizumab.
Trial registration: ClinicalTrials.gov NCT00252135.