IFNB1 and asthma: The INEXAS (A Study in Asthma Patients to Evaluate Efficacy, Safety, and Tolerability of 14 Days Once Daily Inhaled Interferon Beta-1a after the Onset of Symptoms of an Upper Respiratory Tract Infection for the Prevention of Severe Exacerbations) trial also found small improvements in morning peak flow following use of inhaled IFN-β, but again, the primary endpoint was not met and the impact of inhaled IFN-β on the rate of severe asthma exacerbations was unable to be assessed (236).