Background and importance New biological antiasthmatic therapies have been recently developed. In the absence of comparative studies of these therapies, there is a need to provide a better understanding of their behaviour in the real world. Omalizumab is the first monoclonal antibody for the add-on treatment of severe allergic asthma (SAA).

Aim and objectives To evaluate the effectiveness and safety of omalizumab in SAA.

Material and methods A retrospective observational study was conducted in all patients with SAA who were started on omalizumab treatment since 2009. Through pharmacy recordings and electronic clinical records, we collected demographic variables, treatment data (mean dose at baseline and changes during treatment, treatment duration until the last medical review (LMR), need for oral corticosteroids (CO)), forced expiratory volume in 1 s (FEV₁), scores in the asthma control test (ACT), adverse drug reactions (ADR) and reasons for treatment discontinuation.

Results Forty-six patients were included, 63% women, median age 45 years (range 10–74). The mean values for FEV₁ at baseline, week 16 and LMR were 65±17%, 77±18% and 80±20%, respectively. FEV₁ >80% was reached in 58.7% (27/46) of patients; in 26% (12/46) it increased by an average of 13% although FEV₁ >80% was not reached. In the remaining patients (15.3% (7/46)), FEV₁ decreased by an average of 11% compared with baseline. Data from the ACT questionnaire were recorded in only 37% (17/46) of patients with the following results: total control (ACT >25) in 23.5% (4/17), good control (ACT 20–24) in 29.4% (5/17) and poor control (ACT <20) in 47.1% (8/17). At the beginning of treatment, 67.3% (31/46) of patients required daily administration of CO compared with only 10.8% after omalizumab treatment. Regarding ADR, 28% (13/46) of patients suffered any ADR. Treatment was stopped in 15 patients (inefficacy (n=5), ADR (n=5), non-compliance (n=1), clinical improvement (n=4)) after an average treatment duration of 24 months.

Conclusion and relevance Omalizumab improved lung function in patients with SAA, eliminating the use of CO and with an acceptable safety profile. We noticed that there is a need to improve the registration of some clinical parameters in order to ensure adequate therapy monitoring that will help to provide knowledge of the role of each of these therapies.

References and/or acknowledgements No conflict of interest.