Pragmatic Randomized Controlled Trial for Stepping Down Asthma Controller Treatment in Patients Controlled with Low-Dose Inhaled Corticosteroid and Long-Acting β₂-Agonist: Step-Down of Intervention and Grade in Moderate Asthma Study

Background: Current asthma guidelines recommend stepping down controller treatment when the condition is well-controlled for a certain time. However, the optimal step-down strategy for well-controlled patients receiving a low-dose inhaled corticosteroid (ICS) with a long-acting β₂-agonist (LABA) remains unclear. Objective: This study was a randomized, open-label, three-arm, parallel pragmatic trial comparing two kinds of step-down approaches for maintaining treatment. Methods: Adults with asthma who were aged 18 years or older, and who had been stable with low-dose ICS/LABA for at least 3 months, were enrolled. Subjects (n = 225) were randomly allocated into one of three groups (maintaining low-dose ICS/LABA [G1], discontinuing LABA [G2], and reducing ICS/LABA to once daily [G3]), and were observed for 6 months. The primary end point was a change in Asthma Control Test (ACT) scores between randomization and the final 6-month follow-up. Results: The change in ACT was analyzed in the per-protocol population; noninferiority was not demonstrated in either step-down group compared with the maintenance group (95% confidence interval of the difference, G2 vs G1 = –1.40-0.55; G3 vs G1 = –1.19-0.77). Although over 90% of patients were fine, higher rates of treatment failure were observed in step-down groups (G1: 0%; G2: 9.46%; and G3: 9.09%; P = .027). There were no significant differences between step-down approaches in terms of ACT change or treatment failure. Conclusions: Both step-down methods were not noninferior to maintenance of treatment. Step-down therapy can be attempted when patients are stable, but appropriate monitoring and supervision are necessary with precautions regarding loss of disease control.