Impact of omalizumab on treatment of severe allergic asthma in UK clinical practice: A UK multicentre observational study (the APEX II study)

Objective: To describe the impact of omalizumab on asthma management in patients treated as part of normal clinical practice in the UK National Health Service (NHS). Design: A non-interventional, mixed methodology study, combining retrospective and prospective data collection for 12 months pre-omalizumab and postomalizumab initiation, respectively. Setting: Data were collected in 22 UK NHS centres, including specialist centres and district general hospitals in the UK. Participants: 258 adult patients (aged .16 years; 65% women) with severe persistent allergic asthma treated with omalizumab were recruited, of whom 218 (84.5%) completed the study. Primary and secondary outcome measures: The primary outcome measure was change in mean daily dose of oral corticosteroids (OCS) between the 12-month pre-omalizumab and post-omalizumab initiation periods. A priori secondary outcome measures included response to treatment, changes in OCS dosing, asthma exacerbations, lung function, employment/education, patient-reported outcomes and hospital resource utilisation. Results: The response rate to omalizumab at 16 weeks was 82.4%. Comparing pre-omalizumab and postomalizumab periods, the mean (95% CIs) daily dose of OCS decreased by 1.61 (.2.41 to .0.80) mg/patient/day (p