Reddel HK, Brusselle G, Lamarca R, Gustafson P, Anderson GP, Jorup C. J Allergy Clin Immunol Pract. 2023 Apr 11:S2213-2198(23)00398-7. doi: 10.1016/j.jaip.2023.03.046. Epub ahead of print.
Background
As-needed low-dose inhaled corticosteroid (ICS)-formoterol reliever is recommended in patients with asthma prescribed maintenance ICS-formoterol. Clinicians often ask whether ICS-formoterol reliever can be used with other maintenance ICS-long-acting β2-agonists.
Objective
To evaluate the safety and effectiveness of as-needed formoterol in patients taking maintenance ICS-formoterol or ICS-salmeterol from the RELIEF study.
Methods
RELIEF (SD-037-0699) was a 6-month, open-label study that randomized 18,124 patients with asthma to as-needed formoterol 4.5 μg or salbutamol 200 μg on top of maintenance therapy. This post hoc analysis included patients on maintenance ICS-formoterol or ICS-salmeterol (n = 5436). The primary safety outcome was a composite of serious adverse events (SAEs) and/or adverse events leading to discontinuation (DAEs); the primary effectiveness outcome was time-to-first exacerbation.
Results
For both maintenance groups and both relievers, similar numbers of patients had ≥1 SAE and/or DAE. In patients taking maintenance ICS-salmeterol, but not ICS-formoterol, significantly more non-asthma-related and nonserious DAEs occurred with as-needed formoterol versus as-needed salbutamol (P = .0066 and P = .0034, respectively). In patients taking maintenance ICS-formoterol, there was a significantly lower risk in time-to-first exacerbation with as-needed formoterol versus as-needed salbutamol (hazard ratio [HR]: 0.82, 95% confidence interval [CI]: 0.70, 0.95; P = .007). In patients taking ICS-salmeterol maintenance, time-to-first exacerbation was not significantly different between treatment arms (HR: 0.95, 95% CI: 0.84, 1.06; P = .35).
Conclusions
As-needed formoterol significantly reduced exacerbation risk compared with as-needed salbutamol when added to maintenance ICS-formoterol, but not to maintenance ICS-salmeterol. More DAEs were seen with ICS-salmeterol maintenance therapy plus as-needed formoterol. Further research is needed to assess whether this is relevant to as-needed combination ICS-formoterol.