Aztreonam for inhalation solution (AZLI) in patients with cystic fibrosis, mild lung impairment, and P. aeruginosa.

BACKGROUND: Previous aztreonam for inhalation solution (AZLI) studies included patients with cystic fibrosis, Pseudomonas aeruginosa (PA) airway infection, and forced expiratory volume in 1s (FEV(1)) 25% to 75% predicted. This double-blind, multicenter, randomized, placebo-controlled trial enrolled patients (≥6 years) with FEV(1)>75% predicted.

METHODS: AZLI 75 mg (n=76) or placebo (n=81) was administered 3-times daily for 28days with a 14-day follow-up.

RESULTS: Day 28 treatment effects were 1.8points for CFQ-R-Respiratory Symptoms Scale (95%CI: -2.8, 6.4; p=0.443; primary endpoint); -1.2 for log(10) sputum PA colony-forming units (p=0.016; favoring AZLI), and 2.7% for relative FEV(1)% predicted (p=0.021; favoring AZLI). Treatment effects favoring AZLI were larger for patients with baseline FEV(1) <90% predicted compared to ≥90% predicted. AZLI was well-tolerated.

CONCLUSIONS: Effects on respiratory symptoms were modest; however, FEV(1) improvements and bacterial density reductions support a possible role for AZLI in these relatively healthy patients.