Testing the effects of combining azithromycin with inhaled tobramycin for P. aeruginosa in cystic fibrosis: a randomised, controlled clinical trial.

RATIONALE: Inhaled tobramycin and oral azithromycin are common chronic therapies in people with cystic fibrosis and Pseudomonas aeruginosa airway infection. Some studies have shown that azithromycin can reduce the ability of tobramycin to kill P. aeruginosa. This trial was done to test the effects of combining azithromycin with inhaled tobramycin on clinical and microbiological outcomes in people already using inhaled tobramycin. We theorised that those randomised to placebo (no azithromycin) would have greater improvement in forced expiratory volume in one second (FEV1) and greater reduction in P. aeruginosa sputum in response to tobramycin. METHODS: A 6-week prospective, randomised, placebo-controlled, double-blind trial testing oral azithromycin versus placebo combined with clinically prescribed inhaled tobramycin in individuals with cystic fibrosis and P. aeruginosa airway infection. RESULTS: Over a 6-week period, including 4 weeks of inhaled tobramycin, the relative change in FEV1 did not statistically significantly differ between groups (azithromycin (n=56) minus placebo (n=52) difference: 3.44%; 95% CI: -0.48 to 7.35; p=0.085). Differences in secondary clinical outcomes, including patient-reported symptom scores, weight and need for additional antibiotics, did not significantly differ. Among the 29 azithromycin and 35 placebo participants providing paired sputum samples, the 6-week change in P. aeruginosa density differed in favour of the placebo group (difference: 0.75 log10 CFU/mL; 95% CI: 0.03 to 1.47; p=0.043). CONCLUSIONS: Despite having greater reduction in P. aeruginosa density in participants able to provide sputum samples, participants randomised to placebo with inhaled tobramycin did not experience significantly greater improvements in lung function or other clinical outcomes compared with those randomised to azithromycin with tobramycin.

Most Short Children with Cystic Fibrosis Do Not Catch Up by Adulthood.

Poor linear growth is common in children with cystic fibrosis (CF) and predicts pulmonary status and mortality. Growth impairment develops in infancy, prior to pulmonary decline and despite aggressive nutritional measures. We hypothesized that growth restriction during early childhood in CF is associated with reduced adult height. We used the Cystic Fibrosis Foundation (CFF) patient registry to identify CF adults between 2011 and 2015 (ages 18-19 y, n = 3655) and had height for age (HFA) records between ages 2 and 4 y. We found that only 26% CF adults were ≥median HFA and 25% were <10th percentile. Between 2 and 4 years, those with height < 10th percentile had increased odds of being <10th percentile in adulthood compared to children ≥ 10th percentile (OR = 7.7). Of HFA measured between the 10th and 25th percentiles at ages 2-4, 58% were <25th percentile as adults. Only 13% between the 10th and 25th percentile HFA at age 2-4 years were >50th percentile as adults. Maximum height between ages 2 and 4 highly correlated with adult height. These results demonstrate that low early childhood CF height correlates with height in adulthood. Since linear growth correlates with lung growth, identifying both risk factors and interventions for growth failure (nutritional support, confounders of clinical care, and potential endocrine involvement) could lead to improved overall health.

Evaluation of airway and circulating inflammatory biomarkers for cystic fibrosis drug development.

INTRODUCTION: Biomarkers of inflammation in blood and sputum can play a critical role in anti-inflammatory drug development in cystic fibrosis (CF). The objectives of this analysis were to examine relationships between airway and systemic measurements of inflammation, associations between inflammatory biomarkers and FEV1, differences in airway and systemic inflammation by baseline covariates, reproducibility of serum biomarkers, and to assess the effects of freezing and delayed processing on sputum analyte measurements. METHODS: We analyzed baseline and serial concentrations of inflammatory markers in blood and induced sputum collected from individuals with CF ages 10 years and older who participated in a multicenter clinical trial. RESULTS: Among circulating biomarkers, serum high sensitivity C-reactive protein (hsCRP) and serum amyloid A (SAA) correlated most strongly with each other (rs = 0.85). Comparing sputum-based inflammation measurements, sputum neutrophil elastase and myeloperoxidase (MPO) were the most highly correlated (rs = 0.88). Markers most strongly correlated with ppFEV1 were serum hsCRP (rs = -0.55), SAA (rs =-0.58), and sputum neutrophil elastase (rs = -0.53). Within-subject standard deviation was consistently lower than between-subject standard deviation for all serum biomarkers. Serum calprotectin and MPO had the highest ratio of between-to-within subject variability. Freezing and delayed sputum processing were not associated with significant differences in measurements of sputum neutrophil elastase, IL-1ß, or MPO. CONCLUSIONS: Among the biomarkers analyzed, serum hsCRP and sputum neutrophil elastase are promising candidates to include in CF anti-inflammatory clinical trials to avoid redundancy, minimize variation, and serve as correlates of lung disease severity and change.

Oral Glutathione and Growth in Cystic Fibrosis: A Multicenter, Randomized, Placebo-controlled, Double-blind Trial.

OBJECTIVES: The nutritional status of children with cystic fibrosis (CF) is associated with mortality and morbidity. Intestinal inflammation may contribute to impaired digestion, absorption, and nutrient utilization in patients with CF and oral glutathione may reduce inflammation, promoting improved nutritional status in patients with CF. METHODS: The GROW study was a prospective, multicenter, randomized, placebo-controlled, double-blind, phase II clinical trial in pancreatic insufficient patients with CF between the ages of 2 and 10 years. Patients received reduced glutathione or placebo orally daily for 24 weeks. The primary endpoint was the difference in change in weight-for-age z-scores from baseline through week 24 between treatment groups. Secondary endpoints included other anthropometrics, serum, and fecal inflammatory markers in addition to other clinical outcomes. RESULTS: Fifty-eight participants completed the study. No significant differences were seen between glutathione (n = 30) and placebo (n = 28) groups in the 6-month change in weight-for-age z-score (-0.08; 95% CI: -0.22 to 0.06; P = 0.25); absolute change in weight (kg) (-0.18; 95% CI: -0.55 to 0.20; P = 0.35); or absolute change in BMI kg/m (-0.06; 95% CI: -0.37 to 0.25; P = 0.69). There were no significant differences in other secondary endpoints. Overall, glutathione was safe and well tolerated. CONCLUSIONS: Oral glutathione supplementation did not impact growth or change serum or fecal inflammatory markers in pancreatic insufficient children with CF when compared with placebo.

Effectiveness of ivacaftor in cystic fibrosis patients with non-G551D gating mutations.

BACKGROUND: The cystic fibrosis transmembrane conductance regulator (CFTR) potentiator ivacaftor is approved for patients with CF with gating and residual function CFTR mutations. We report the results of an observational study investigating its effects in CF patients with non-G551D gating mutations. METHODS: Patients with non-G551D gating mutations were recruited to an open-label study evaluating ivacaftor. Primary outcomes included: lung function, sweat chloride, weight gain, and quality of life scores. RESULTS: Twenty-one subjects were enrolled and completed 6 months follow-up on ivacaftor; mean age was 25.6 years with 52% <18. Baseline ppFEV1 was 68% and mean sweat chloride 89.6 mEq/L. Participants experienced significant improvements in ppFEV1 (mean absolute increase of 10.9% 95% CI = [2.6,19.3], p = 0.0134), sweat chloride (-48.6 95% CI = [-67.4,-29.9], p < 0.0001), and weight (5.1 kg, 95% CI = [2.8, 7.3], p = 0.0002). CONCLUSIONS: Patients with non-G551D gating mutations experienced improved lung function, nutritional status, and quality of life. This study supports ongoing use of ivacaftor for patients with these mutations.

Microbiological efficacy of early MRSA treatment in cystic fibrosis in a randomised controlled trial.

OBJECTIVE: To evaluate microbiological effectiveness, that is, culture negativity of a non-blinded eradication protocol (Rx) compared with observation (Obs) in clinically stable cystic fibrosis participants with newly positive methicillin resistant Staphylococcusaureus (MRSA) cultures. DESIGN: This non-blinded trial randomised participants ages 4-45 years with first or early (≤2 positive cultures within 3 years) MRSA-positive culture without MRSA-active antibiotics within 4 weeks 1:1 to Rx or Obs. The Rx protocol was: oral trimethoprim-sulfamethoxazole or if sulfa-allergic, minocycline plus oral rifampin; chlorhexidine mouthwash for 2 weeks; nasal mupirocin and chlorhexidine body wipes for 5 days and environmental decontamination for 21 days. The primary end point was MRSA culture status at day 28. RESULTS: Between 1 April 2011 to September 2014, 45 participants (44% female, mean age 11.5 years) were randomised (24 Rx, 21 Obs). At day 28, 82% (n=18/22) of participants in the Rx arm compared with 26% (n=5/19) in the Obs arm were MRSA-negative. Adjusted for interim monitoring, this difference was 52% (95% CI 23% to 80%, p<0.001). Limiting analyses to participants who were MRSA-positive at the screening visit, 67% (8/12) in the Rx arm and 13% (2/15) in the Obs arm were MRSA-negative at day 28, adjusted difference: 49% (95% CI 22% to 71%, p<0.001). Fifty-four per cent in the Rx arm compared with 10% participants in the Obs arm remained MRSA-negative through day 84. Mild gastrointestinal side effects were higher in the Rx arm. CONCLUSIONS: This MRSA eradication protocol for newly acquired MRSA demonstrated microbiological efficacy with a large treatment effect. TRIAL REGISTRATION NUMBER: NCT01349192.

Pseudomonas aeruginosa in cystic fibrosis patients with G551D-CFTR treated with ivacaftor.

BACKGROUND: Ivacaftor improves outcomes in cystic fibrosis (CF) patients with the G551D mutation; however, effects on respiratory microbiology are largely unknown. This study examines changes in CF respiratory pathogens with ivacaftor and correlates them with baseline characteristics and clinical response. METHODS: The G551D Observational Study enrolled a longitudinal observational cohort of US patients with CF aged 6 years and older with at least 1 copy of the G551D mutation. Results were linked with retrospective and prospective culture data in the US Cystic Fibrosis Foundation's National Patient Registry. Pseudomonas aeruginosa infection category in the year before and year after ivacaftor was compared and correlated with clinical findings. RESULTS: Among 151 participants prescribed ivacaftor, 29% (26/89) who were culture positive for P. aeruginosa the year prior to ivacaftor use were culture negative the year following treatment; 88% (52/59) of those P. aeruginosa free remained uninfected. The odds of P. aeruginosa positivity in the year after ivacaftor compared with the year prior were reduced by 35% (odds ratio [OR], 0.65; P < .001). Ivacaftor was also associated with reduced odds of mucoid P. aeruginosa (OR, 0.77; P = .013) and Aspergillus (OR, 0.47; P = .039), but not Staphylococcus aureus or other common CF pathogens. Patients with intermittent culture positivity and higher forced expiratory volume in 1 second (FEV1) were most likely to turn culture negative. Reduction in P. aeruginosa was not associated with change in FEV1, body mass index, or hospitalizations. CONCLUSIONS: Pseudomonas aeruginosa culture positivity was significantly reduced following ivacaftor treatment. Efficacious CFTR modulation may contribute to lower frequency of culture positivity for P. aeruginosa and other respiratory pathogens, particularly in patients with less established disease.

Pulmonary exacerbations and parent-reported outcomes in children <6 years with cystic fibrosis.

Pulmonary exacerbations (PEs) are used as clinical endpoints in infants and preschool children with cystic fibrosis (CF); however, their characteristics and impact in this age range are poorly understood. We used data from the Infant Study of Inhaled Saline, a multicenter trial of inhaled hypertonic versus isotonic saline, to describe PEs in children with CF <6 years and evaluate associations between PEs and parent-reported outcomes assessed by a weekly parent questionnaire (10 items) and three scales of the Cystic Fibrosis Questionnaire-Revised (CFQ-R), and other participant characteristics. There were 659 PEs among 253 of the 321 ISIS participants (mean age 2.3 years) during 287 participant-years follow-up. Of the 659 PEs, 636 (97%) were treated with oral and 45 (7%) with IV antibiotics (not mutually exclusive). Among 222 participants with PEs who had completed parent questionnaires during a PE and at baseline, 9 of the 10 symptoms were each present in a statistically significantly higher proportion of participants during a PE than at baseline. Lower (worse) baseline Respiratory Symptom and Physical Functioning CFQ-R scores were significantly associated with higher PE rate: rate ratio 1.08 (95%CI: 1.02, 1.14) and 1.21 (1.07, 1.36) per 10 point lower score in respective scale. A higher PE rate was also significantly associated with worse CFQ-R Respiratory Symptom and Physical Functioning scores at the end of the study, adjusted for baseline scores. Though most PEs did not require IV antibiotics, PEs appeared to have a negative impact on parent-reported health outcomes in infants and preschoolers with CF. Pediatr Pulmonol. 2015; 50:236-243. © 2014 Wiley Periodicals, Inc.