The Effect of Inhaled IFN-β on Worsening of Asthma Symptoms Caused by Viral Infections: A Randomized Trial

Ex vivo, bronchial epithelial cells from people with asthma are more susceptible to rhinovirus infection caused by deficient induction of the antiviral protein, IFN-β. Exogenous IFN-β restores antiviral activity. To compare the efficacy and safety of inhaled IFN-β with placebo administered to people with asthma after onset of cold symptoms to prevent or attenuate asthma symptoms caused by respiratory viruses. A total of 147 people with asthma on inhaled corticosteroids (British Thoracic Society Steps 2-5), with a history of virus-associated exacerbations, were randomized to 14-day treatment with inhaled IFN-β (n = 72) or placebo (n = 75) within 24 hours of developing cold symptoms and were assessed clinically, with relevant samples collected to assess virus infection and antiviral responses. A total of 91% of randomized patients developed a defined cold. In this modified intention-to-treat population, asthma symptoms did not get clinically significantly worse (mean change in six-item Asthma Control Questionnaire