Increased tumour necrosis factor-α levels have been observed in bronchial biopsies and induced sputum from subjects with severe asthma. We investigated etanercept (ETN) as a therapeutic option for treating moderate-to-severe persistent asthma.

In this 12-week, randomised, double-blind, placebo-controlled, phase 2 trial, subjects (n = 132) with moderate-to-severe persistent asthma received subcutaneous injections of 25 mg ETN or placebo twice weekly, and were evaluated at baseline, and at weeks 2, 4, 8 and 12. The primary end-point was the change from baseline to week 12 in pre-bronchodilator forced expiratory volume in 1 s (FEV₁) % predicted. Secondary end-points included morning peak expiratory flow, FEV₁ % pred, Asthma Control Questionnaire (5-item version), asthma exacerbations, provocative concentration of methacholine causing a 20% decrease in FEV₁, and the Asthma Quality of Life Questionnaire.

No significant differences were observed between ETN and placebo for any of the efficacy end-points. ETN treatment was well tolerated, with no unexpected safety findings observed during the study.

Clinical efficacy of ETN was not shown in subjects with moderate-to-severe persistent asthma over 12 weeks. However, ETN treatment was a well-tolerated therapy. Studies in specific subsets of patients with asthma with longer-term follow-up may be needed to fully evaluate the clinical efficacy of ETN in this population.