Long-term evaluation of omalizumab therapy in patients with severe allergic asthma

Aim: Evaluation of real-world data regarding the use of omalizumab on lung function, asthma control, exacerbations, and oral corticosteroid (OCS). Methods: The single-centre, retrospective study included data from adult patients with severe allergic asthma treated with omalizumab for at least five years to ten years to evaluate its long-term efficacy. The primary outcome parameters were lung function (FEV1), the asthma control test (ACT) score, the number of exacerbations, and OCS use. Results: Data from 74 adults (mean age 51 years, 61% females, median IgE 276 kU/L), with severe allergic asthma, due to perennial allergens, who were treated for at least 5 years with omalizumab in one centre could be evaluated up to 10 years. The mean improvement in FEV1 from baseline was 13.4% in the first year and constantly remained high throughout the duration of the treatment. The ACT improved from baseline (12.4 points) to 16.4 in the first year and reached 18.8 after 5 years, followed by values nearly reaching 20 (19.2 in year 8). The rate of exacerbations decreased from 3.3 events in the last 12 months before omalizumab initiation to 0.4 in the first year and remained low (e.g., 0.2 after 5 years). The mean OCS use was 20.9 mg/day in 44/74 patients before the first injection of omalizumab and decreased to 5 mg/day in the same patients within the first year. Following 6 years of omalizumab treatment, OCSs were used by 22 patients, and by 12 patients after 8 years. Conclusions: The consistent improvement in lung function, asthma control, reduction in exacerbations, and OCS use throughout a minimum of five up to ten years confirms that omalizumab remains effective for many years. There were no signs of tolerance or tachyphylaxis against the biologic.