Aztreonam for Inhalation Solution vs Tobramycin Inhalation Solution in Patients With Cystic Fibrosis & Pseudomonas Aeruginosa

Number of Subjects Planned: Approximately 240 randomized patients Target Population: CF patients \>= 6 years of age with stable pulmonary disease, who at study entry had a recent positive sputum culture for PA and had been previously treated with aerosolized antibiotics without demonstration of drug intolerance. The randomized phase of this study, used for hypotheses testing, enrolled participants from both the United States (US) and EU. An open-label, single-arm extension was available for participants in the EU who completed at least one course of AZLI or TIS during the randomized portion of the study. These participants were eligible to receive 3 additional cycles of AZLI in a 28-day, intermittent, repeating treatment regimen. Results of the extension phase will be available the first quarter (Q1) of 2012. Randomized Phase Study Design (US and EU): This was an open-label, multicenter, randomized, parallel group study. The study design consisted of 2 treatment arms of 28-day, intermittent, repeating treatment regimens: aztreonam for inhalation solution (AZLI) or tobramycin inhalation solution (TIS). The total study period was 26 weeks. The study schedule included 9 visits - Screening, Baseline, Day 14, Day 28, followed by visits every 28 days through the end of the study.