Clinical Outcomes Following Transition from ICS/LABA to Single-Inhaler Triple Therapy in Patients with Uncontrolled Asthma: A Real-World Cohort Study

Background and Objectives: A considerable proportion of patients with asthma remain inadequately controlled despite treatment with inhaled corticosteroid/long-acting β2-agonist (ICS/LABA) therapy. Single-inhaler triple therapy comprising an inhaled corticosteroid, a long-acting β2-agonist, and a long-acting muscarinic antagonist (ICS/LABA/LAMA) has emerged as an effective step-up treatment; however, real-world evidence remains limited. This study aimed to evaluate the effects of transitioning from high-dose ICS/LABA therapy to single-inhaler triple therapy on asthma control, lung function, and exacerbation-related outcomes in routine clinical practice. Materials and Methods: This retrospective observational study included adult patients with uncontrolled asthma who were switched from high-dose ICS/LABA therapy to single-inhaler triple therapy at a tertiary referral center. Demographic characteristics, Asthma Control Test (ACT) scores, pulmonary function tests, blood eosinophil counts, exacerbation frequency, oral corticosteroid (OCS)-requiring exacerbations, short-acting β2-agonist (SABA) use, emergency department visits, and hospitalizations were compared before and after treatment escalation using paired statistical analyses. Results: Nineteen patients (mean age 58.9 ± 10.4 years; 63.2% female) were included. Following transition to single-inhaler triple therapy, asthma control improved significantly, with mean ACT scores increasing from 14.8 ± 3.2 to 23.4 ± 3.6 (p < 0.001). Mean forced expiratory volume in one second (FEV1) increased from 1692.6 ± 722.7 mL to 2020.5 ± 871.5 mL, while predicted FEV1 improved from 64.2 ± 21.2% to 75.6 ± 21.6% (both p < 0.001). Total annual exacerbation frequency decreased from a median of 2 (interquartile range [IQR], 1–3) to 0 (IQR, 0–1; p = 0.0005), and 78.9% of patients experienced at least one fewer exacerbation. Significant reductions were also observed in OCS-requiring exacerbations, SABA use, emergency department visits, hospitalizations, and blood eosinophil counts. Conclusions: In this real-world cohort, transitioning from ICS/LABA therapy to single-inhaler triple therapy was associated with statistically significant improvements in asthma control and lung function, together with substantial reductions in exacerbation burden and healthcare utilization. These findings support the effectiveness of single-inhaler triple therapy as a step-up treatment strategy for patients with uncontrolled asthma in routine clinical practice.