A CFTR Potentiator in Patients with Cystic Fibrosis and the G551D Mutation

Background:

Increasing the activity of defective cystic fibrosis transmembrane conductance regulator (CFTR) protein is a potential treatment for cystic fibrosis.

Methods:

We conducted a randomized, double-blind, placebo-controlled trial to evaluate ivacaftor (VX-770), a CFTR potentiator, in subjects 12 years of age or older with cystic fibrosis and at least one G551D-CFTR mutation. Subjects were randomly assigned to receive 150 mg of ivacaftor every 12 hours (84 subjects, of whom 83 received at least one dose) or placebo (83, of whom 78 received at least one dose) for 48 weeks. The primary end point was the estimated mean change from baseline through week 24 in the percent of predicted forced expiratory volume in 1 second (FEV1).

Results:

The change from baseline through week 24 in the percent of predicted FEV1 was greater by 10.6 percentage points in the ivacaftor group than in the placebo group (P < 0.001). Effects on pulmonary function were noted by 2 weeks, and a significant treatment effect was maintained through week 48. Subjects receiving ivacaftor were 55% less likely to have a pulmonary exacerbation than were patients receiving placebo, through week 48 (P < 0.001). In addition, through week 48, subjects in the ivacaftor group scored 8.6 points higher than did subjects in the placebo group on the respiratory-symptoms domain of the Cystic Fibrosis Questionnaire-revised instrument (a 100-point scale, with higher numbers indicating a lower effect of symptoms on the patient's quality of life) (P < 0.001). By 48 weeks, patients treated with ivacaftor had gained, on average, 2.7 kg more weight than had patients receiving placebo (P < 0.001). The change from baseline through week 48 in the concentration of sweat chloride, a measure of CFTR activity, with ivacaftor as compared with placebo was -48.1 mmol per liter (P < 0.001). The incidence of adverse events was similar with ivacaftor and placebo, with a lower proportion of serious adverse events with ivacaftor than with placebo (24% vs. 42%).

Conclusions:

Ivacaftor was associated with improvements in lung function at 2 weeks that were sustained through 48 weeks. Substantial improvements were also observed in the risk of pulmonary exacerbations, patient-reported respiratory symptoms, weight, and concentration of sweat chloride.

Akt-Mediated Proinflammatory Response of Mononuclear Phagocytes Infected with Burkholderia cenocepacia Occurs by a Novel GSK3 beta-Dependent, I kappa B Kinase-Independent Mechanism

The environmental bacterium Burkholderia cenocepacia causes opportunistic lung infections in immunocompromised individuals, particularly in patients with cystic fibrosis. Infections in these patients are associated with exacerbated inflammation leading to rapid decay of lung function, and in some cases resulting in cepacia syndrome, which is characterized by a fatal acute necrotizing pneumonia and sepsis. B. cenocepacia can survive intracellularly in macrophages by altering the maturation of the phagosome, but very little is known on macrophage responses to the intracellular infection. In this study, we have examined the role of the PI3K/Akt signaling pathway in B. cenocepacia-infected monocytes and macrophages. We show that PI3K/Akt activity was required for NF-kappa B activity and the secretion of proinflammatory cytokines during infection with B. cenocepacia. In contrast to previous observations in epithelial cells infected with other Gram-negative bacteria, Akt did not enhance I kappa B kinase or NF-kappa B p65 phosphorylation, but rather inhibited GSK3 beta, a negative regulator of NF-kappa B transcriptional activity. This novel mechanism of modulation of NF-kappa B activity may provide a unique therapeutic target for controlling excessive inflammation upon B. cenocepacia infection. The Journal of Immunology, 2011, 187: 635-643.

Interactions of Burkholderia cenocepacia and other Burkholderia cepacia complex bacteria with epithelial and phagocytic cells

Burkholderia cenocepacia is a member of the B. cepacia complex (Bcc), a group of opportunistic bacteria that infect the airways of patients with cystic fibrosis (CF) and are extraordinarily resistant to almost all clinically useful antibiotics. Infections in CF patients with Bcc bacteria generally lead to a more rapid decline in lung function, and in some cases to the 'cepacia syndrome', a virtually deadly exacerbation of the lung infection with systemic manifestations. These characteristics of Bcc bacteria contribute to higher morbidity and mortality in infected CF patients. In the last 10 years considerable progress has been made in understanding the interactions between Bcc bacteria and mammalian host cells. Bcc isolates can survive either intracellularly within eukaryotic cells or extracellularly in host tissues. They survive within phagocytes and respiratory epithelial cells, and they have the ability to breach the respiratory epithelium layer. Survival and persistence of Bcc bacteria within host cells and tissues are believed to play a key role in pulmonary infection and to contribute to the persistent inflammation observed in patients with CF. This review summarizes recent findings concerning the interaction between Bcc bacteria and epithelial and phagocytic cells.

Intracellular survival of Burkholderia cepacia complex isolates in the presence of macrophage cell activation

Strains of the Burkholderia cepacia complex have emerged as a serious threat to patients with cystic fibrosis due to their ability to infect the lung and cause, in some patients, a necrotizing pneumonia that is often lethal. It has recently been shown that several strains of the B. cepacia complex can escape intracellular killing by free-living amoebae following phagocytosis. In this work, the ability of two B. cepacia complex strains to resist killing by macrophages was explored. Using fluorescence microscopy, electron microscopy and a modified version of the gentamicin-protection assay, we demonstrate that B. cepacia CEP021 (genomovar VI), and Burkholderia vietnamiensis (previously B. cepacia genomovar V) CEP040 can survive in PU5-1.8 murine macrophages for a period of at least 5 d without significant bacterial replication. Furthermore, bacterial entry into macrophages stimulated production of tumour necrosis factor and primed them to release toxic oxygen radicals following treatment with phorbol myristoyl acetate. These effects were probably caused by bacterial LPS, as they were blocked by polymyxin B. Infected macrophages primed with interferon gamma produced less nitric oxide than interferon-gamma-primed uninfected cells. We propose that the ability of B. cepacia to resist intracellular killing by phagocytic cells may play a role in the pathogenesis of cystic fibrosis lung infection. Our data are consistent with a model where repeated cycles of phagocytosis and cellular activation without bacterial killing may promote a deleterious inflammatory response causing tissue destruction and decay of lung function.

Tobramycin Inhalation Powder™:a novel drug delivery system for treating chronic Pseudomonas aeruginosa infection in cystic fibrosis

Lung disease in cystic fibrosis (CF) is typified by the development of chronic airways infection culminating in bronchiectasis and progression to end-stage respiratory disease. Pseudomonas aeruginosa, a ubiquitous gram-negative bacteria, is the archetypical CF pathogen and is associated with an accelerated clinical decline. The development and widespread use of chronic suppressive aerosolized antibacterial therapies, in particular Tobramycin Inhalation Solution (TIS), in CF has contributed to reduced lung function decline and improved survival. However, the requirement for the aerosolization of these agents through nebulizers has been associated with increased treatment burden, reduced quality of life and remain a barrier to broader uptake. Tobramycin Inhalation Powder (TIP™) has been developed by Novartis with the express purpose of delivering the same benefits as TIS in a time-effective manner. Administered via the T-326™ (Novartis) Inhaler in four individual 28-mg capsules, TIP can be administered in a quarter of the time of traditional nebulizers and is inherently portable. In clinical studies, TIP has been shown to be safe, result in equivalent or superior reductions in P. aeruginosa sputum density and produce similar improvements in pulmonary function. TIP offers significant advantages in time saving, portability and convenience over traditional nebulized TIS with comparable clinical outcomes for individuals with CF.

Clinical management and outcome of refractory asthma in the UK from the British Thoracic Society Difficult Asthma Registry

Refractory asthma represents a significant unmet clinical need. Data from a national online registry audited clinical outcome in 349 adults with refractory asthma from four UK specialist centres in the British Thoracic Society Difficult Asthma Network. At follow-up, lung function improved, with a reduction in important healthcare outcomes, specifically hospital admission, unscheduled healthcare visits and rescue courses of oral steroids. The most frequent therapeutic intervention was maintenance oral corticosteroids and most steroid sparing agents (apart from omalizumab) demonstrated minimal steroid sparing benefit. A significant unmet clinical need remains in this group, specifically a requirement for therapies which reduce systemic steroid exposure.

The Adult Cystic Fibrosis Airway Microbiota Is Stable over Time and Infection Type, and Highly Resilient to Antibiotic Treatment of Exacerbations

Cystic fibrosis (CF) is characterized by defective mucociliary clearance and chronic airway infection by a complex microbiota. Infection, persistent inflammation and periodic episodes of acute pulmonary exacerbation contribute to an irreversible decline in CF lung function. While the factors leading to acute exacerbations are poorly understood, antibiotic treatment can temporarily resolve pulmonary symptoms and partially restore lung function. Previous studies indicated that exacerbations may be associated with changes in microbial densities and the acquisition of new microbial species. Given the complexity of the CF microbiota, we applied massively parallel pyrosequencing to identify changes in airway microbial community structure in 23 adult CF patients during acute pulmonary exacerbation, after antibiotic treatment and during periods of stable disease. Over 350,000 sequences were generated, representing nearly 170 distinct microbial taxa. Approximately 60% of sequences obtained were from the recognized CF pathogens Pseudomonas and Burkholderia, which were detected in largely non-overlapping patient subsets. In contrast, other taxa including Prevotella, Streptococcus, Rothia and Veillonella were abundant in nearly all patient samples. Although antibiotic treatment was associated with a small decrease in species richness, there was minimal change in overall microbial community structure. Furthermore, microbial community composition was highly similar in patients during an exacerbation and when clinically stable, suggesting that exacerbations may represent intrapulmonary spread of infection rather than a change in microbial community composition. Mouthwash samples, obtained from a subset of patients, showed a nearly identical distribution of taxa as expectorated sputum, indicating that aspiration may contribute to colonization of the lower airways. Finally, we observed a strong correlation between low species richness and poor lung function. Taken together, these results indicate that the adult CF lung microbiome is largely stable through periods of exacerbation and antibiotic treatment and that short-term compositional changes in the airway microbiota do not account for CF pulmonary exacerbations.

Efficacy, safety and effect on biomarkers of AZD9668 in cystic fibrosis

The aim of this study was to evaluate the safety and effect on clinical outcomes and biomarkers of inflammation and tissue damage of the neutrophil elastase inhibitor AZD9668 (60 mg twice daily orally for 4 weeks) in cystic fibrosis. This was a randomised, double-blind, placebo-controlled study. Primary outcome measures were sputum neutrophil count, lung function, 24-h sputum weight, BronkoTest® diary card data and health-related quality-of-life (revised cystic fibrosis quality-of-life questionnaire). Secondary end-points included sputum neutrophil elastase activity, inflammatory biomarkers in sputum and blood, urine and plasma desmosine (an elastin degradation marker), AZD9668 levels and safety parameters (adverse events, routine haematology, biochemistry, electrocardiogram and sputum bacteriology). 56 patients were randomised, of which 27 received AZD9668. There was no effect for AZD9668 on sputum neutrophil counts, neutrophil elastase activity, lung function or clinical outcomes, including quality of life. In the AZD9668 group, there was a trend towards reduction in sputum inflammatory biomarkers with statistically significant changes in interleukin-6, RANTES and urinary desmosine. The pattern of adverse events was similar between groups. Consistent reductions in sputum inflammatory biomarkers were seen in the AZD9668 group, and reduction in urinary desmosine suggests that AZD9668 impacts elastin cleavage by neutrophil elastase.

Impact of cigarette smoke exposure on host-bacterial pathogen interactions

The human respiratory tract of individuals with normal lung function maintains a fine-tuned balance, being asymptomatically colonised by the normal microbiota in the upper airways and sterile in the lower tract. This equilibrium may be disrupted by the exposure to insults such as cigarette smoke. In the respiratory tract, the complex and noxious nature of inhaled cigarette smoke alters host-microorganisminteraction dynamics at all anatomical levels, causing infections in many cases. Moreover, continuous exposure to cigarette smoke itself causes deleterious effects on the host that can trigger the development of chronic respiratory diseases, such as chronic obstructive pulmonary disease (COPD) and lung cancer. COPD is an irreversible airflow obstruction associated with emphysema, fibrosis, mucus hypersecretion and persistent colonisation of the lower airways by opportunistic pathogens. COPD patients keep a stable (without exacerbation) but progressively worsening condition and suffer periodic exacerbations caused, in most cases, by infections. Although smoking and smoking-associated diseases are associated with a high risk of infection, most therapies aim to reduce inflammatory parameters, but do not necessarily take into account the presence of persistent colonisers. The effect of cigarette smoke on host-pathogen interaction dynamics in the respiratory tract, together with current and novel therapies, is discussed. Copyright©ERS 2012.

Inflammatory and immunological biomarkers are not related to survival in adults with Cystic Fibrosis

Background
Chronic Pseudomonas aeruginosa pulmonary infection is associated with a decline in lung function and reduced survival in people with Cystic Fibrosis (CF). Damaging inflammatory and immunological mediators released in the lungs can be used as markers of chronic infection, inflammation and lung tissue damage.

Methods
Clinical samples were collected from CF patients and healthy controls. Serum IgG and IgA anti-Pseudomonas antibodies, sputum IL-8 and TNFα, plasma IL-6 and urine TNFr1 were measured by ELISA. Sputum neutrophil elastase (NE), cathepsin S and cathepsin B were measured by spectrophotometric and fluorogenic assays. The relationship between IgG and IgA, inflammatory mediators and long-term survival was determined.

Results
IgG and IL-6 positively correlated with mortality. However, multivariate analysis demonstrated that after adjusting for FEV1, IgG was not independently related to mortality. A relationship was observed between IgG and IL-6, TNFα, TNFr1 and between IgA and IL8, cathepsin S and cathepsin B.

Conclusions
These data indicate that biomarkers of inflammation are not independent predictors of survival in people with CF.

The TORCH (towards a revolution in COPD health) survival study protocol

Only long-term home oxygen therapy has been shown in randomised controlled trials to increase survival in chronic obstructive pulmonary disease (COPD). There have been no trials assessing the effect of inhaled corticosteroids and long-acting bronchodilators, alone or in combination, on mortality in patients with COPD, despite their known benefit in reducing symptoms and exacerbations. The "TOwards a Revolution in COPD Health" (TORCH) survival study is aiming to determine the impact of salmeterol/fluticasone propionate (SFC) combination and the individual components on the survival of COPD patients. TORCH is a multicentre, randomised, double-blind, parallel-group, placebo-controlled study. Approximately 6,200 patients with moderate-to-severe COPD were randomly assigned to b.i.d. treatment with either SFC (50/500 microg), fluticasone propionate (500 microg), salmeterol (50 microg) or placebo for 3 yrs. The primary end-point is all-cause mortality; secondary end-points are COPD morbidity relating to rate of exacerbations and health status, using the St George's Respiratory Questionnaire. Other end-points include other mortality and exacerbation end-points, requirement for long-term oxygen therapy, and clinic lung function. Safety end-points include adverse events, with additional information on bone fractures. The first patient was recruited in September 2000 and results should be available in 2006. This paper describes the "TOwards a Revolution in COPD Health" study and explains the rationale behind it.

Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis

Background Person-to-person transmission of respiratory pathogens, including Pseudomonas aeruginosa, is a challenge facing many cystic fibrosis (CF) centres. Viable P aeruginosa are contained in aerosols produced during coughing, raising the possibility of airborne transmission.

Methods Using purpose-built equipment, we measured viable P aeruginosa in cough aerosols at 1, 2 and 4 m from the subject (distance) and after allowing aerosols to age for 5, 15 and 45 min in a slowly rotating drum to minimise gravitational settling and inertial impaction (duration). Aerosol particles were captured and sized employing an Anderson Impactor and cultured using conventional microbiology. Sputum was also cultured and lung function and respiratory muscle strength measured.

Results Nineteen patients with CF, mean age 25.8 (SD 9.2) years, chronically infected with P aeruginosa, and 10 healthy controls, 26.5 (8.7) years, participated. Viable P aeruginosa were detected in cough aerosols from all patients with CF, but not from controls; travelling 4 m in 17/18 (94%) and persisting for 45 min in 14/18 (78%) of the CF group. Marked inter-subject heterogeneity of P aeruginosa aerosol colony counts was seen and correlated strongly (r=0.73-0.90) with sputum bacterial loads. Modelling decay of viable P aeruginosa in a clinic room suggested that at the recommended ventilation rate of two air changes per hour almost 50 min were required for 90% to be removed after an infected patient left the room.

Conclusions: Viable P aeruginosa in cough aerosols travel further and last longer than recognised previously, providing additional evidence of airborne transmission between patients with CF.

Rifampicin and sodium fusidate reduces the frequency of methicillin-resistant Staphylococcus aureus (MRSA) isolation in adults with cystic fibrosis and chronic MRSA infection

Nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) to patients with cystic fibrosis (CF) frequently results in chronic respiratory tract carriage. This is an increasing problem, adds to the burden of glycopeptide antibiotic use in hospitals, and represents a relative contraindication to lung transplantation. The aim of this study was to determine whether it is possible to eradicate MRSA with prolonged oral combination antibiotics, and whether this treatment is associated with improved clinical status. Adult CF patients (six male, one female) with chronic MRSA infection were treated for six months with rifampicin and sodium fusidate. Outcome data were examined for six months before treatment, on treatment and after treatment. The patients had a mean age of 29.3 (standard deviation=6.3) years and FEV(1) of 36.1% (standard deviation=12.7) predicted. The mean duration of MRSA isolation was 31 months. MRSA isolates identified in these patients was of the same lineage as the known endemic strain at the hospital when assessed by pulsed-field gel electrophoresis. Five of the seven had no evidence of MRSA during and for at least six months after rifampicin and sodium fusidate. The proportion of sputum samples positive for MRSA was lower during the six months of treatment (0.13) and after treatment (0.19) compared with before treatment (0.85) (P<0.0001). There was a reduction in the number of days of intravenous antibiotics per six months with 20.3+/-17.6 on treatment compared with 50.7 before treatment and 33.0 after treatment (P=0.02). There was no change in lung function. Gastrointestinal side effects occurred in three, but led to therapy cessation in only one patient. Despite the use of antibiotics with anti-staphylococcal activity for treatment of respiratory exacerbation, MRSA infection persists. MRSA can be eradicated from the sputum of patients with CF and chronic MRSA carriage by using rifampicin and sodium fusidate for six months. This finding was associated with a significant reduction in the duration of intravenous antibiotic treatment during therapy.

Characterisation of the frequent exacerbator phenotype in COPD patients in a large UK primary care population

BACKGROUND: The 'frequent exacerbator' is recognised as an important phenotype in COPD. Current understanding about this phenotype comes from prospective longitudinal clinical trials in secondary/tertiary care with little information reported in primary care populations.

AIMS: To characterize the frequent-exacerbator phenotype and identify associated risk factors in a large UK primary care COPD population.

METHODS: Using a large database of primary care patients from 80 UK general practices, patients were categorised using GOLD 2014 criteria into high and low risk groups based on exacerbation history. A multivariate logistic regression model was used to investigate covariates associated with the frequent-exacerbator phenotype and risk of experiencing a severe exacerbation (leading to hospitalisation).

RESULTS: Of the total study population (n = 9219), 2612 (28%) fulfilled the criteria for high risk frequent-exacerbators. Independent risk factors (adjusted odds ratio [95% CI]) for ≥2 exacerbations were: most severely impaired modified Medical Research Council (mMRC) dyspnoea score (mMRC grade 4: 4.37 [2.64-7.23]), lower FEV1 percent predicted (FEV1 <30%: 2.42 [1.61-3.65]), co-morbid cardiovascular disease (1.42 [1.19-1.68]), depression (1.56 [1.22-1.99]) or osteoporosis (1.54 [1.19-2.01]), and female gender (1.20 [1.01-1.43]). Older patients (≥75 years), those with most severe lung impairment (FEV1 <30%), those with highest mMRC score and those with co-morbid osteoporosis were identified as most at risk of experiencing exacerbations requiring hospitalisation.

CONCLUSIONS: Although COPD exacerbations occur across all grades of disease severity, female patients with high dyspnoea scores, more severely impaired lung function and co-morbidities are at greatest risk. Elderly patients, with severely impaired lung function, high mMRC scores and osteoporosis are associated with experience of severe exacerbations requiring hospitalisation.

Tiotropium and olodaterol fixed-dose combination versus mono-components in COPD (GOLD 2-4)

Efficacy and safety of tiotropium+olodaterol fixed-dose combination (FDC) compared with the mono-components was evaluated in patients with moderate to very severe chronic obstructive pulmonary disease (COPD) in two replicate, randomised, double-blind, parallel-group, multicentre, phase III trials. Patients received tiotropium+olodaterol FDC 2.5/5 μg or 5/5 μg, tiotropium 2.5 μg or 5 μg, or olodaterol 5 μg delivered once-daily via Respimat inhaler over 52 weeks. Primary end points were forced expiratory volume in 1 s (FEV1) area under the curve from 0 to 3 h (AUC0-3) response, trough FEV1 response and St George's Respiratory Questionnaire (SGRQ) total score at 24 weeks. In total, 5162 patients (2624 in Study 1237.5 and 2538 in Study 1237.6) received treatment. Both FDCs significantly improved FEV1 AUC0-3 and trough FEV1 response versus the mono-components in both studies. Statistically significant improvements in SGRQ total score versus the mono-components were only seen for tiotropium+olodaterol FDC 5/5 μg. Incidence of adverse events was comparable between the FDCs and the mono-components. These studies demonstrated significant improvements in lung function and health-related quality of life with once-daily tiotropium+olodaterol FDC versus mono-components over 1 year in patients with moderate to very severe COPD.