Achieving clinical remission by using different treatment options in patients with severe asthma

Severe asthma (SA) is treated by conventional therapy and biologics. The percentage of patients with SA who achieve clinical remission (CR) in a real clinical practice needs further investigation. The aim of this study was to assess the rate of CR in SA patients treated with conventional therapy only or conventional therapy + biologics during 5 years in a single secondary care center. Methods. We examined 138 adult outpatients (32% male, aged 18 – 81 years) with SA every 3 – 6 months for 5 years. Eighty-six patients were treated by conventional therapy only and 52 patients additionally received biologics [omalizumab ( n = 10), mepolizumab/benralizumab ( n = 22), dupilumab ( n = 20). Lung function was assessed by spirometry with bronchodilator reversibility test using Spirograph 2120 (Vitalograph, Great Britain). Blood eosinophils (EOS) were measured by impedance methods using an automatic haemoanalyser. Atopic status was determined by positive skin prick-test (> 3 mm) and/or serum specific IgE to common inhalant allergens. Exhaled nitric oxide (FeNO) was measured by a chemiluminescence analyzer (Logan-4100; Logan Research, Rochester, UK). Asthma control and quality of life were assessed by using the Russian versions of ACQ-5 and St. George’s Respiratory Questionnaire (SGRQ). Clinical remission was defined as absence of exacerbations and systemic corticosteroid (SCS) use during previous year, controlled/partly controlled symptoms (mean ACQ-5 < 1,5), and optimal/best lung function (FEV1 ≥ 80% predicted/FEV1 increase ≥ 100 ml). These criteria were assessed every year. Statistical analyses were performed using parametric and non-parametric methods with Statistica 0.0 (StatSoft, Inc., USA). Results. During this 5-year study, CR was reached in about 20% of SA patients additionally treated with biologics and in about 7% of patients who received conventional therapy only. CR was more frequent in patients with preserved baseline lung function, absence of maintenance SCS use, rare exacerbations, better asthma control and quality of life. The number of SA patients who fulfilled CR criteria was higher after 3 years of biologics treatment. Conclusion. During 5 years of follow-up, the rate of CR in patients with SA treated with biologics was approximately three times higher compared to those treated with conventional therapy only. It confirms that biologics treatment needs to be started earlier and continued if effective.