Serious Asthma Events with Budesonide plus Formoterol vs. Budesonide Alone

Concerns remain about the safety of adding long-acting β2-agonists to inhaled glucocorticoids for the treatment of asthma. In a postmarketing safety study mandated by the Food and Drug Administration, we evaluated whether the addition of formoterol to budesonide maintenance therapy increased the risk of serious asthma-related events in patients with asthma.

In this multicenter, double-blind, 26-week study, we randomly assigned patients, 12 years of age or older, who had persistent asthma, were receiving daily asthma medication, and had had one to four asthma exacerbations in the previous year to receive budesonide-formoterol or budesonide alone. Patients with a history of life-threatening asthma were excluded. The primary end point was the first serious asthma-related event (a composite of adjudicated death, intubation, and hospitalization), as assessed in a time-to-event analysis. The noninferiority of budesonide-formoterol to budesonide was defined as an upper limit of the 95% confidence interval for the risk of the primary safety end point of less than 2.0. The primary efficacy end point was the first asthma exacerbation, as assessed in a time-to-event analysis.

A total of 11,693 patients underwent randomization, of whom 5846 were assigned to receive budesonide-formoterol and 5847 to receive budesonide. A serious asthma-related event occurred in 43 patients who were receiving budesonide-formoterol and in 40 patients who were receiving budesonide (hazard ratio, 1.07; 95% confidence interval [CI], 0.70 to 1.65]); budesonide-formoterol was shown to be noninferior to budesonide alone. There were two asthma-related deaths, both in the budesonide-formoterol group; one of these patients had undergone an asthma-related intubation. The risk of an asthma exacerbation was 16.5% lower with budesonide-formoterol than with budesonide (hazard ratio, 0.84; 95% CI, 0.74 to 0.94; P=0.002).

Among adolescents and adults with predominantly moderate-to-severe asthma, treatment with budesonide-formoterol was associated with a lower risk of asthma exacerbations than budesonide and a similar risk of serious asthma-related events. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT01444430 .).