A novel inhaled phosphodiesterase 4 inhibitor (CHF6001) reduces the allergen challenge response in asthmatic patients

Abstract CHF6001 is an inhaled phosphodiesterase 4 (PDE4) inhibitor in development for the treatment of obstructive lung diseases. We investigated the efficacy and safety of CHF6001 using the allergen challenge model in a double blind, placebo controlled, 3-way cross-over study. Thirty six atopic asthmatics who were not taking inhaled corticosteroids and who demonstrated a late asthmatic response (LAR) to inhaled allergen at screening were randomised to receive CHF6001 400 μg or 1200 μg or placebo administered once a day using a dry powder inhaler. The three treatment periods were 9 days; allergen challenges were performed on day 9 and induced sputum was obtained after 10 h from challenge. Washout periods between treatments were up to 5 weeks. Both CHF6001 doses significantly attenuated the LAR; the primary endpoint analysis showed that CHF6001 400 μg and 1200 μg caused reductions of 19.7% (p = 0.015) and 28.2% (p