TNF-alpha has been widely studied in asthma and proposed as a possible target for the treatment of severe asthma. Unfortunately, toxic effects of monoclonal antibodies against TNF-alpha have precluded their use in patients with severe disease. Moreover, the clinical benefits have always been very small.
A new trial assessed the efficacy and safety of ethanercept, a biologic against TNF-apha (fusion protein of TNF-alpha receptor), in moderate-to-severe persistent asthma. In a 12-week, randomized, double-blind, placebo-controlled, phase 2 trial, 132 subjects with asthma received subcutaneous injections of etanercept or placebo twice weekly.
Clinical efficacy of etanercept was not shown in any of the outcomes studied over 12 weeks. However, etanercept treatment was well-tolerated.
The authors propose that studies in specific subsets of patients with asthma with longer-term follow-up may be needed to fully evaluate the clinical efficacy of etanercept in asthma.