Relative change in percentage predicted FEV1 in the Intent-to-treat (ITT), modified ITT (mITT) and Observed cases in the ITT populations were calculated from an adjusted analysis ANOVA model. ITT Patients with missing or unacceptable Day 29 spirometry measurements had their primary endpoint data imputed with zero. BSL = Baseline, defined as the latest measurement prior to the first dosing of study medication \- Relative change = 100 \* (value - baseline) / baseline There were 3 patients who had no screening nor baseline values (due to inadequate spirometry) and so were excluded from all change from baseline analyses.

Absolute change in percentage predicted FEV1 in the Intent-to-treat (ITT), modified ITT (mITT) and Observed cases in the ITT populations were calculated from an adjusted analysis ANOVA model. In the adjusted analysis model: response = treatment + screening FEV1 % predicted (\<50 and \>=50) + age (\<13 and \>=13) + error. Significance for the FEV1 % predicted is reached for p-values \<= 0.05. There were 3 patients who had no screening nor baseline values (due to inadequate spirometry) and so were excluded from all change from baseline analyses.

Relative change in percentage predicted FEV1 without outlier (outliers with respect to FEV1 values and PK data), in the Intent-to-treat (ITT), modified ITT (mITT) and Observed cases in the ITT populations were calculated from an adjusted analysis ANOVA model.

An adverse event (AE) is any untoward medical occurrence, including any unfavorable and unintended sign, symptom or disease temporally associated with the use of the study medication that does not necessarily have a causal relationship with study medication. A serious AE (SAE) is an event that results in death, is life-threatening, requires or prolongs inpatient hospitalization, results in persistent or significant disability, is a congenital anomaly or defect, or is a significant medical event that may jeopardize the patient or require intervention to prevent one of the outcomes listed above.

Microbiological samples were obtained from sputum or by deep throat cough swab technique. Time to recurrence was defined as the time between the visit at 1 month after the end of treatment (when eradication was confirmed) and the time of the first positive culture with any genotype of P. aeruginosa. Time zero was Day 56 (Month 2) for the 28-day treatment group and Month 3 for the 56-day treatment group. Kaplan-Meier estimates were used.