Introduction: GINA guidelines recommend increasing the dose of inhaled corticosteroids (ICS) as a step-up option for patients with inadequately controlled asthma at GINA step 4 [inadequately controlled asthma on medium-dose ICS/long-acting beta-2 agonist (LABA)]. The aim of this study was to compare the efficacy and safety of long-acting muscarinic antagonists (LAMA) add-on to medium-dose ICS/LABA in patients at GINA 2022 step 4.
Methods: This post hoc analysis of the IRIDIUM study evaluated the change from baseline in trough forced expiratory volume (FEV1 ) in patients receiving medium-dose MF/IND/GLY versus high-dose MF/IND and high-dose FLU/SAL at Week 26. Other outcomes included improvement in lung functions [peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory flow between 25% and 75% of the FVC (FEF)25-75%)], asthma control [Asthma Control Questionnaire (ACQ-7)], responder analysis (≥ 0.5 unit improvement in ACQ-7), and reduction in asthma exacerbations at Weeks 26 and 52.
Results: A total of 1930 patients were included in this analysis. Medium-dose MF/IND/GLY improved trough FEV1 versus high-dose MF/IND (Δ 41 mL; 95% CI - 7-90) and high-dose FLU/SAL (Δ 88 mL; 95% CI 39-137) at Week 26 which were sustained until Week 52. Exacerbation rates were 16% lower with medium-dose MF/IND/GLY versus high-dose MF/IND for all (mild, moderate, and severe) exacerbations and 21-30% lower versus high-dose FLU/SAL for all (mild, moderate, and severe), moderate or severe, and severe exacerbations over 52 weeks. Further improvements in other lung functions were observed with medium-dose MF/IND/GLY. No new safety signals were identified.
Conclusion: Medium-dose MF/IND/GLY improved lung function and reduced asthma exacerbations compared to high-dose ICS/LABA and may be an undervalued option in patients at GINA 2022 step 4.
Trial registration: ClinicalTrials.gov Identifier: NCT02571777.