Efficacy of omalizumab, an anti-immunoglobulin E antibody, in patients with allergic asthma at high risk of serious asthma-related morbidity and mortality
Aim: Add-on therapy with omalizumab, an anti-immunoglobulin E antibody, is effective in improving disease control in patients with allergic asthma of varying severity. The aim of the present study was to determine the efficacy of omalizumab in a subgroup of patients at high risk of serious asthma-related morbidity and mortality.
Methods: A meta-analysis was performed of three randomised, double-blind, placebo-controlled studies (studies 1, 2 and 3) that enrolled 1412 patients with moderate or severe allergic asthma, all requiring daily treatment with inhaled corticosteroids (ICS). Omalizumab was administered subcutaneously every 2 or 4 weeks at a total 4-weekly dose of at least 0.016mg/kg/IgE [IU/ml]. Each study consisted of a 16-week steroid-stable phase and a 12-16-week steroid-reduction phase, followed by a 24-week extension phase (studies 1 and 2 only). The primary outcome measure was the annualised rate of significant asthma exacerbation episodes (sAEEs) during the steroid-stable phase for the pooled subgroup of 254 high-risk patients (omalizumab, n=135; placebo, n=119). sAEEs were those requiring a doubling of baseline ICS dose (studies 1 and 2 only) or use of systemic steroids (all three studies).
Results: Overall, the number of patients with at least one sAEE during the steroid-stable phase was reduced from 35% (42/119) with placebo to 18% (24/135) with omalizumab. Mean sAEE rates were 1.56 and 0.69 per patient-year, respectively, a reduction of 56% with omalizumab (p=0.007). Similar reductions in exacerbations in favour of omalizumab were observed for the whole study period and for all AEEs. In those with a history of hospitalisation in the last year, 6/49 (12%) on placebo vs. 2/44 (4.5%) on omalizumab were re-hospitalised during the study period. Patients treated with omalizumab also showed significantly greater improvements from baseline in PEFR (p=0.026), overall AQoL (p=0.042) and mean nocturnal (p=0.007) and mean total (p=0.011) asthma symptom scores compared with placebo.
Conclusions: In patients at high risk of serious asthma-related morbidity and mortality, treatment with omalizumab offers the potential to halve the rate of asthma exacerbations and improve disease control.
Holgate, S., Bousquet, J., Wenzel, S., Fox, H., Liu, J., & Castellsague, J. (2001). Efficacy of omalizumab, an anti-immunoglobulin E antibody, in patients with allergic asthma at high risk of serious asthma-related morbidity and mortality. Current Medical Research and Opinion, 17(4), 233-240.