Effectiveness of anti-IgE and anti-IL-5 treatment in step 5 asthma patients.

Introduction: According to the global strategy for asthma management and prevention 2017, patients with persistent symptoms and exacerbations should be referred to a specialist, despite correct inhaler techniques and adherence with step 4 treatment,. It is important to define which add-on treatments are best for each patient. In Japan, anti-IgE monoclonal antibody omalizumab and anti-IL-5 antibody mepolizumab have approved for treatment. Purpose: To evaluate the clinical effectiveness of anti-IL5 treatment in step 5 asthma patients. Methods: We investigated patient characteristics: gender, age, and the number of patients for each treatment step in bronchial asthma patients during a four-month period from October 2017 to January 2018. Patients defined as in treatment for step 5 were analyzed. Results: Of 184 bronchial asthma patients, 34 (18.5%) required step 5 treatment. Of these, 25 patients required additional treatment. Based on clinical data, 18 patients presented with blood IgE concentration ＞30 or＜1500 IU/ml and a positive reaction to a perennial aeroallergen. Among the 18 patients, 9 had eosinophil counts of at least 150 cells/μl. We administered omalizumab for 12 patients and mepolizumab for 4 patients. For 3 of the patients mepolizumab was administrated after omalizumab 16-week trial. There was no exacerbation observed in patients administered mepolizumab over the 24-week period. Conclusions: In this study, 18.5% of bronchial asthma patients required step 5 treatment. Nine patients had indications for both omalizumab and mepolizumab. It is important to select the best treatment to ensure optimal asthma control for each patient.