Effect of multiple aztreonam lysine for inhalation (AZLI) cycles on disease-related endpoints and safety in patients with cystic fibrosis (CF) and Pseudomonas aeruginosa (PA): Interim analysis of 12 month data

Aztreonam lysine: a novel inhalational antibiotic for cystic fibrosis

Acquisition of Pseudomonas aeruginosa, the most prevalent organism isolated from cystic fibrosis (CF) airways, is associated with an accelerated clinical deterioration and reduced survival. Strategies to chronically suppress P. aeruginosa infections in individuals with CF have evolved over the last four decades and now largely focus on regular administration of aerosolized antibiotics. Aztreonam lysine (AZLI; Cayston, Gilead Pharmaceuticals [Foster City, CA, USA]), a novel formulation of the monobactam aztreonam suitable for aerosol delivery has recently been developed. AZLI is administered as 75 mg three-times daily for 28 days in 'on/off' cycles using the Altera/eFlow electronic nebulizer (PARI Innovative Manufacturers [Midlothian, VA, USA]). In individuals with CF chronically infected with P. aeruginosa, AZLI improved healthcare-associated quality-of-life scores, pulmonary function and weight, prolonged time to requirement of antibacterial therapy for symptoms of pulmonary exacerbation and reduced P. aeruginosa sputum burdens. These outcomes were durable over 18 months of cycled use. AZLI has been demonstrated to be safe and effective, and expands available chronic maintenance therapies in CF.

Efficacy and safety of inhaled aztreonam lysine for airway pseudomonas in cystic fibrosis

BACKGROUND

We assessed the short-term efficacy and safety of aztreonam lysine for inhalation (AZLI [an aerosolized monobactam antibiotic]) in patients with cystic fibrosis (CF) and Pseudomonas aeruginosa (PA) airway infection.

METHODS

In this randomized, double-blind, placebo-controlled, international study (AIR-CF1 trial; June 2005 to April 2007), patients (n = 164; >or= 6 years of age) with FEV(1) >or= 25% and <or= 75% predicted values, and no recent use of antipseudomonal antibiotics or azithromycin were treated with 75 mg of AZLI (three times daily for 28 days) or placebo (1:1 randomization), then were monitored for 14 days after study drug completion. The primary efficacy end point was change in patient-reported respiratory symptoms (CF-Questionnaire-Revised [CFQ-R] Respiratory Scale). Secondary end points included changes in pulmonary function (FEV(1)), sputum PA density, and nonrespiratory CFQ-R scales. Adverse events and minimum inhibitory concentrations of aztreonam for PA were monitored.

RESULTS

After 28 days of treatment, AZLI improved the mean CFQ-R respiratory score (9.7 points; p < 0.001), FEV(1) (10.3% predicted; p < 0.001), and sputum PA density (- 1.453 log(10) cfu/g; p < 0.001), compared with placebo. Significant improvements in Eating, Emotional Functioning, Health Perceptions, Physical Functioning, Role Limitation/School Performance, and Vitality CFQ-R scales were observed. Adverse events were consistent with symptoms of CF lung disease and were comparable for AZLI and placebo except the incidence of "productive cough" was reduced by half in AZLI-treated patients. PA aztreonam susceptibility at baseline and end of therapy were similar.

CONCLUSIONS

In patients with CF, PA airway infection, moderate-to-severe lung disease, and no recent use of antipseudomonal antibiotics or azithromycin, 28-day treatment with AZLI significantly improved respiratory symptoms and pulmonary function, and was well tolerated.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00112359.