This study will investigate the safety, tolerability, pharmacokinetic, and pharmacodynamic response of patients with cystic fibrosis to administration of QAU145 via intranasal spray.

Inclusion Criteria:

• Male and female (women must be post-menopausal or surgically sterile) subjects with cystic fibrosis ages 18 to 50.

Exclusion Criteria:

• Any presence of seasonal or non-seasonal allergies affecting the nose, nasal passages, throat or sinuses within 2 weeks prior to dosing.
• Any upper respiratory tract infection or signs or symptoms within 2 weeks prior to dosing.
• Any presence of nasal polyps or structural abnormalities, frequent history of nose bleeding, or any recent nasal surgery (within 12 weeks prior to dosing).