Inhaled JAK inhibitor GDC-0214 reduces exhaled nitric oxide in patients with mild asthma: A randomized, controlled, proof-of-activity trial.

Background: The Janus kinase (JAK) pathway mediates the activity of many asthma-relevant cytokines, including IL-4 and IL-13. GDC-0214 is a potent, inhaled, small-molecule JAK inhibitor being developed for the treatment of asthma.

Objective: We sought to determine whether GDC-0214 reduces fractional exhaled nitric oxide (Feno), a JAK1-dependent biomarker of airway inflammation, in patients with mild asthma.