The primary purpose of this study is to evaluate the safety and tolerability of three active doses of nebulized amikacin in a SLIT™ formulation.

Inclusion Criteria:

• Study participants must produce sputum that is positive for Pseudomonas aeruginosa.
• Confirmed diagnosis of CF (positive sweat chloride >60 milliequivalents (mEq)/liter (by pilocarpine iontophoresis) and/or a genotype with two identifiable mutations consistent with CF accompanied by one or more clinical features with the CF phenotype.
• Forced expiratory volume (FEV1) ≥40% predicted at Screening as calculated by the Knudsen reference equations.
• Clinically stable with no evidence of current pulmonary exacerbation.

Exclusion Criteria:

• History of lung transplantation.
• Use of intravenous antibiotics or oral quinolones within 14 days of Screening.
• Use of low dose oral antibiotics (e.g. tetracycline, sulfa) for acne or other conditions within 30 days of Screening.
• Use of systemic corticosteroids (≥20 milligrams [mg] of prednisone per day) within 30 days of Screening.
• Initiation of TOBI® (tobramycin), high dose ibuprofen, recombinant human DNase (rhDNase), or macrolide antibiotics within 60 days of Screening.
• History of sputum or throat swab culture yielding Burkholderia cepacia complex within 2 years of Screening or growth of Burkholderia cepacia complex from the sputum or throat swab culture obtained at Screening.
• History of biliary cirrhosis, portal hypertension, or splenomegaly or splenomegaly on physical exam at Screening or enrollment.
• History of daily continuous oxygen supplementation or requirement for more than 2 liter per minute (L/min) at night.

Note: Other inclusion/exclusion criteria may apply.