A phase 3, open-label, randomized trial to evaluate the safety and efficacy of levofloxacin inhalation solution (APT-1026) versus tobramycin inhalation solution in stable cystic fibrosis patients

Antibiotic strategies for eradicating Pseudomonas aeruginosa in people with cystic fibrosis

BACKGROUND

Respiratory tract infections with Pseudomonas aeruginosa occur in most people with cystic fibrosis (CF). Established chronic P aeruginosa infection is virtually impossible to eradicate and is associated with increased mortality and morbidity. Early infection may be easier to eradicate. This is an updated review.

OBJECTIVES

Does giving antibiotics for P aeruginosa infection in people with CF at the time of new isolation improve clinical outcomes (e.g. mortality, quality of life and morbidity), eradicate P aeruginosa infection, and delay the onset of chronic infection, but without adverse effects, compared to usual treatment or an alternative antibiotic regimen? We also assessed cost-effectiveness.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and conference proceedings. Latest search: 24 March 2022. We searched ongoing trials registries. Latest search: 6 April 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of people with CF, in whom P aeruginosa had recently been isolated from respiratory secretions. We compared combinations of inhaled, oral or intravenous (IV) antibiotics with placebo, usual treatment or other antibiotic combinations. We excluded non-randomised trials and cross-over trials.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, assessed risk of bias and extracted data. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 11 trials (1449 participants) lasting between 28 days and 27 months; some had few participants and most had relatively short follow-up periods. Antibiotics in this review are: oral - ciprofloxacin and azithromycin; inhaled - tobramycin nebuliser solution for inhalation (TNS), aztreonam lysine (AZLI) and colistin; IV - ceftazidime and tobramycin. There was generally a low risk of bias from missing data. In most trials it was difficult to blind participants and clinicians to treatment. Two trials were supported by the manufacturers of the antibiotic used. TNS versus placebo TNS may improve eradication; fewer participants were still positive for P aeruginosa at one month (odds ratio (OR) 0.06, 95% confidence interval (CI) 0.02 to 0.18; 3 trials, 89 participants; low-certainty evidence) and two months (OR 0.15, 95% CI 0.03 to 0.65; 2 trials, 38 participants). We are uncertain whether the odds of a positive culture decrease at 12 months (OR 0.02, 95% CI 0.00 to 0.67; 1 trial, 12 participants). TNS (28 days) versus TNS (56 days) One trial (88 participants) comparing 28 days to 56 days TNS treatment found duration of treatment may make little or no difference in time to next isolation (hazard ratio (HR) 0.81, 95% CI 0.37 to 1.76; low-certainty evidence). Cycled TNS versus culture-based TNS One trial (304 children, one to 12 years old) compared cycled TNS to culture-based therapy and also ciprofloxacin to placebo. We found moderate-certainty evidence of an effect favouring cycled TNS therapy (OR 0.51, 95% CI 0.31 to 0.82), although the trial publication reported age-adjusted OR and no difference between groups. Ciprofloxacin versus placebo added to cycled and culture-based TNS therapy One trial (296 participants) examined the effect of adding ciprofloxacin versus placebo to cycled and culture-based TNS therapy. There is probably no difference between ciprofloxacin and placebo in eradicating P aeruginosa (OR 0.89, 95% CI 0.55 to 1.44; moderate-certainty evidence). Ciprofloxacin and colistin versus TNS We are uncertain whether there is any difference between groups in eradication of P aeruginosa at up to six months (OR 0.43, 95% CI 0.15 to 1.23; 1 trial, 58 participants) or up to 24 months (OR 0.76, 95% CI 0.24 to 2.42; 1 trial, 47 participants); there was a low rate of short-term eradication in both groups. Ciprofloxacin plus colistin versus ciprofloxacin plus TNS One trial (223 participants) found there may be no difference in positive respiratory cultures at 16 months between ciprofloxacin with colistin versus TNS with ciprofloxacin (OR 1.28, 95% CI 0.72 to 2.29; low-certainty evidence). TNS plus azithromycin compared to TNS plus oral placebo Adding azithromycin may make no difference to the number of participants eradicating P aeruginosa after a three-month treatment phase (risk ratio (RR) 1.01, 95% CI 0.75 to 1.35; 1 trial, 91 participants; low-certainty evidence); there was also no evidence of any difference in the time to recurrence. Ciprofloxacin and colistin versus no treatment A single trial only reported one of our planned outcomes; there were no adverse effects in either group. AZLI for 14 days plus placebo for 14 days compared to AZLI for 28 days We are uncertain whether giving 14 or 28 days of AZLI makes any difference to the proportion of participants having a negative respiratory culture at 28 days (mean difference (MD) -7.50, 95% CI -24.80 to 9.80; 1 trial, 139 participants; very low-certainty evidence). Ceftazidime with IV tobramycin compared with ciprofloxacin (both regimens in conjunction with three months colistin) IV ceftazidime with tobramycin compared with ciprofloxacin may make little or no difference to eradication of P aeruginosa at three months, sustained to 15 months, provided that inhaled antibiotics are also used (RR 0.84, 95 % CI 0.65 to 1.09; P = 0.18; 1 trial, 255 participants; high-certainty evidence). The results do not support using IV antibiotics over oral therapy to eradicate P aeruginosa, based on both eradication rate and financial cost.

AUTHORS' CONCLUSIONS

We found that nebulised antibiotics, alone or with oral antibiotics, were better than no treatment for early infection with P aeruginosa. Eradication may be sustained in the short term. There is insufficient evidence to determine whether these antibiotic strategies decrease mortality or morbidity, improve quality of life, or are associated with adverse effects compared to placebo or standard treatment. Four trials comparing two active treatments have failed to show differences in rates of eradication of P aeruginosa. One large trial showed that intravenous ceftazidime with tobramycin is not superior to oral ciprofloxacin when inhaled antibiotics are also used. There is still insufficient evidence to state which antibiotic strategy should be used for the eradication of early P aeruginosa infection in CF, but there is now evidence that intravenous therapy is not superior to oral antibiotics.

Current and Emerging Inhaled Antibiotics for Chronic Pulmonary Pseudomonas aeruginosa and Staphylococcus aureus Infections in Cystic Fibrosis

Characterized by impaired mucus transport and subsequent enhanced colonization of bacteria, pulmonary infection causes major morbidity and mortality in patients with cystic fibrosis (CF). Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) are the two most common types of bacteria detected in CF lungs, which undergo multiple adaptational mechanisms such as biofilm formation resulting in chronic pulmonary infections. With the advantages of greater airway concentration and minimized systemic toxicity, inhaled antibiotics are introduced to treat chronic pulmonary infection in CF. Inhaled tobramycin, aztreonam, levofloxacin, and colistin are the four most common discussed inhaled antibiotics targeting P. aeruginosa. Additionally, inhaled liposomal amikacin and murepavadin are also in development. This review will discuss the virulence factors and adaptational mechanisms of P. aeruginosa and S. aureus in CF. The mechanism of action, efficacy and safety, current status, and indications of corresponding inhaled antibiotics will be summarized. Combination therapy and the strategies to select an optimal inhaled antibiotic protocol will also be discussed.

Brazilian guidelines for the pharmacological treatment of the pulmonary symptoms of cystic fibrosis. Official document of the Sociedade Brasileira de Pneumologia e Tisiologia (SBPT, Brazilian Thoracic Association)

Cystic fibrosis (CF) is a genetic disease that results in dysfunction of the CF transmembrane conductance regulator (CFTR) protein, which is a chloride and bicarbonate channel expressed in the apical portion of epithelial cells of various organs. Dysfunction of that protein results in diverse clinical manifestations, primarily involving the respiratory and gastrointestinal systems, impairing quality of life and reducing life expectancy. Although CF is still an incurable pathology, the therapeutic and prognostic perspectives are now totally different and much more favorable. The purpose of these guidelines is to define evidence-based recommendations regarding the use of pharmacological agents in the treatment of the pulmonary symptoms of CF in Brazil. Questions in the Patients of interest, Intervention to be studied, Comparison of interventions, and Outcome of interest (PICO) format were employed to address aspects related to the use of modulators of this protein (ivacaftor, lumacaftor+ivacaftor, and tezacaftor+ivacaftor), use of dornase alfa, eradication therapy and chronic suppression of Pseudomonas aeruginosa, and eradication of methicillin-resistant Staphylococcus aureus and Burkholderia cepacia complex. To formulate the PICO questions, a group of Brazilian specialists was assembled and a systematic review was carried out on the themes, with meta-analysis when applicable. The results obtained were analyzed in terms of the strength of the evidence compiled, the recommendations being devised by employing the GRADE approach. We believe that these guidelines represent a major advance to be incorporated into the approach to patients with CF, mainly aiming to favor the management of the disease, and could become an auxiliary tool in the definition of public policies related to CF.

Inhaled anti-pseudomonal antibiotics for long-term therapy in cystic fibrosis

BACKGROUND

Inhaled antibiotics are commonly used to treat persistent airway infection with Pseudomonas aeruginosa that contributes to lung damage in people with cystic fibrosis. Current guidelines recommend inhaled tobramycin for individuals with cystic fibrosis and persistent Pseudomonas aeruginosa infection who are aged six years or older. The aim is to reduce bacterial load in the lungs so as to reduce inflammation and deterioration of lung function. This is an update of a previously published review.

OBJECTIVES

To evaluate the effects of long-term inhaled antibiotic therapy in people with cystic fibrosis on clinical outcomes (lung function, frequency of exacerbations and nutrition), quality of life and adverse events (including drug-sensitivity reactions and survival).

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched ongoing trials registries. Date of last search: 28 June 2022.

SELECTION CRITERIA

We selected trials where people with cystic fibrosis received inhaled anti-pseudomonal antibiotic treatment for at least three months, treatment allocation was randomised or quasi-randomised, and there was a control group (either placebo, no placebo or another inhaled antibiotic).

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, judged the risk of bias, extracted data from these trials and judged the certainty of the evidence using the GRADE system.

MAIN RESULTS

The searches identified 410 citations to 125 trials; 18 trials (3042 participants aged between five and 45 years) met the inclusion criteria. Limited data were available for meta-analyses due to the variability of trial design and reporting of results. A total of 11 trials (1130 participants) compared an inhaled antibiotic to placebo or usual treatment for a duration between three and 33 months. Five trials (1255 participants) compared different antibiotics, two trials (585 participants) compared different regimens of tobramycin and one trial (90 participants) compared intermittent tobramycin with continuous tobramycin alternating with aztreonam. One trial (18 participants) compared an antibiotic to placebo and also to a different antibiotic and so fell into both groups. The most commonly studied antibiotic was tobramycin which was studied in 12 trials. Inhaled antibiotics compared to placebo We found that inhaled antibiotics may improve lung function measured in a variety of ways (4 trials, 814 participants). Compared to placebo, inhaled antibiotics may also reduce the frequency of exacerbations (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.47 to 0.93; 3 trials, 946 participants; low-certainty evidence). Inhaled antibiotics may lead to fewer days off school or work (quality of life measure) (mean difference (MD) -5.30 days, 95% CI -8.59 to -2.01; 1 trial, 245 participants; low-certainty evidence). There were insufficient data for us to be able to report an effect on nutritional outcomes and there was no effect on survival. There was no effect on antibiotic resistance seen in the two trials that were included in meta-analyses. We are uncertain of the effect of the intervention on adverse events (very low-certainty evidence), but tinnitus and voice alteration were the only events occurring more often in the inhaled antibiotics group. The overall certainty of evidence was deemed to be low for most outcomes due to risk of bias within the trials and imprecision due to low event rates. Different antibiotics or regimens compared Of the eight trials comparing different inhaled antibiotics or different antibiotic regimens, there was only one trial for each unique comparison. We found no differences between groups for any outcomes except for the following. Aztreonam lysine for inhalation probably improved forced expiratory volume at one second (FEV1) % predicted compared to tobramycin (MD -3.40%, 95% CI -6.63 to -0.17; 1 trial, 273 participants; moderate-certainty evidence). However, the method of defining the endpoint was different to the remaining trials and the participants were exposed to tobramycin for a long period making interpretation of the results problematic. We found no differences in any measure of lung function in the remaining comparisons. Trials measured pulmonary exacerbations in different ways and showed no differences between groups except for aztreonam lysine probably leading to fewer people needing treatment with additional antibiotics than with tobramycin (RR 0.66, 95% CI 0.51 to 0.86; 1 trial, 273 participants; moderate-certainty evidence); and there were fewer hospitalisations due to respiratory exacerbations with levofloxacin compared to tobramycin (RR 0.62, 95% CI 0.40 to 0.98; 1 trial, 282 participants; high-certainty evidence). Important treatment-related adverse events were not very common across comparisons, but were reported less often in the tobramycin group compared to both aztreonam lysine and colistimethate. We found the certainty of evidence for these comparisons to be directly related to the risk of bias within the individual trials and varied from low to high.

AUTHORS' CONCLUSIONS

Long-term treatment with inhaled anti-pseudomonal antibiotics probably improves lung function and reduces exacerbation rates, but pooled estimates of the level of benefit were very limited. The best evidence available is for inhaled tobramycin. More evidence from trials measuring similar outcomes in the same way is needed to determine a better measure of benefit. Longer-term trials are needed to look at the effect of inhaled antibiotics on quality of life, survival and nutritional outcomes.

Drugs, Drugs, Drugs: Current Treatment Paradigms in Cystic Fibrosis Airway Infections

Airway infections have remained a prominent feature in persons living with cystic fibrosis (CF) despite the dramatic improvements in survival in the past decades. Antimicrobials are a cornerstone of infection management for both acute and chronic maintenance indications. Historic clinical trials of antimicrobials in CF have led to the adoption of consensus guidelines for their use in clinical care. More recently, however, there are efforts to re-think the optimal use of antimicrobials for care with the advent of novel and highly effective CF transmembrane conductance regulator modulator therapies. Encouragingly, however, drug development has remained active concurrently in this space. Our review focuses on the evidence for and perspectives regarding antimicrobial use in both acute and maintenance settings in persons with CF. The therapeutic innovations in CF and how this may affect antimicrobial approaches are also discussed.

Differential Performance and Lung Deposition of Levofloxacin with Different Nebulisers Used in Cystic Fibrosis

We compared the performance and levofloxacin (Quinsair) lung deposition of three nebulisers commonly used in CF (I-Neb Advance, eFlow rapid, and LC Plus) with the approved nebuliser Zirela. The delivered dose, delivery rate, and aerosol particle size distribution (APSD) for each device were determined using the methods described in the Pharmacopeia. High-resolution computed tomography scans obtained from seven adult patients with mild CF were used to generate computer-aided, three-dimensional models of their airway tree to assess lung deposition using functional respiratory imaging (FRI). The eFlow rapid and the LC Plus showed poor delivery efficiencies due to their high residual volumes. The I-Neb, which only delivers aerosols during the inspiratory phase, achieved the highest aerosol delivery efficiency. However, the I-Neb showed the largest particle size and lowest delivery rate (2.9 mg/min), which were respectively associated with a high extrathoracic deposition and extremely long nebulisation times (>20 min). Zirela showed the best performance considering delivery efficiency (159.6 mg out of a nominal dose of 240 mg), delivery rate (43.5 mg/min), and lung deposition (20% of the nominal dose), requiring less than 5 min to deliver a full dose of levofloxacin. The present study supports the use of drug-specific nebulisers and discourages the off-label use of general-purpose devices with the present levofloxacin formulation since subtherapeutic lung doses and long nebulisation times may compromise treatment efficacy and adherence.

Inhaled antibiotics for pulmonary exacerbations in cystic fibrosis

BACKGROUND

Cystic fibrosis is a genetic disorder in which abnormal mucus in the lungs is associated with susceptibility to persistent infection. Pulmonary exacerbations are when symptoms of infection become more severe. Antibiotics are an essential part of treatment for exacerbations and inhaled antibiotics may be used alone or in conjunction with oral antibiotics for milder exacerbations or with intravenous antibiotics for more severe infections. Inhaled antibiotics do not cause the same adverse effects as intravenous antibiotics and may prove an alternative in people with poor access to their veins. This is an update of a previously published review.

OBJECTIVES

To determine if treatment of pulmonary exacerbations with inhaled antibiotics in people with cystic fibrosis improves their quality of life, reduces time off school or work, and improves their long-term lung function.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Group's Cystic Fibrosis Trials Register. Date of the last search: 7 March 2022. We also searched ClinicalTrials.gov, the Australia and New Zealand Clinical Trials Registry and WHO ICTRP for relevant trials. Date of last search: 3 May 2022.

SELECTION CRITERIA

Randomised controlled trials in people with cystic fibrosis with a pulmonary exacerbation in whom treatment with inhaled antibiotics was compared to placebo, standard treatment or another inhaled antibiotic for between one and four weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible trials, assessed the risk of bias in each trial and extracted data. They assessed the certainty of the evidence using the GRADE criteria. Authors of the included trials were contacted for more information.

MAIN RESULTS

Five trials with 183 participants are included in the review. Two trials (77 participants) compared inhaled antibiotics alone to intravenous antibiotics alone and three trials (106 participants) compared a combination of inhaled and intravenous antibiotics to intravenous antibiotics alone. Trials were heterogenous in design and two were only available in abstract form. Risk of bias was difficult to assess in most trials but, for four out of five trials, we judged there to be a high risk from lack of blinding and an unclear risk with regards to randomisation. Results were not fully reported and only limited data were available for analysis. One trial was a cross-over design and we only included data from the first intervention arm. Inhaled antibiotics alone versus intravenous antibiotics alone Only one trial (18 participants) reported a perceived improvement in lifestyle (quality of life) in both groups (very low-certainty evidence). Neither trial reported on time off work or school. Both trials measured lung function, but there was no difference reported between treatment groups (very low-certainty evidence). With regards to our secondary outcomes, one trial (18 participants) reported no difference in the need for additional antibiotics and the second trial (59 participants) reported on the time to next exacerbation. In neither case was a difference between treatments identified (both very low-certainty evidence). The single trial (18 participants) measuring adverse events and sputum microbiology did not observe any in either treatment group for either outcome (very low-certainty  evidence). Inhaled antibiotics plus intravenous antibiotics versus intravenous antibiotics alone Inhaled antibiotics plus intravenous antibiotics may make little or no difference to quality of life compared to intravenous antibiotics alone. None of the trials reported time off work or school. All three trials measured lung function, but found no difference between groups in forced expiratory volume in one second (two trials; 44 participants; very low-certainty evidence) or vital capacity (one trial; 62 participants). None of the trials reported on the need for additional antibiotics. Inhaled plus intravenous antibiotics may make little difference to the time to next exacerbation; however, one trial (28 participants) reported on hospital admissions and found no difference between groups. There is likely no difference between groups in adverse events (very low-certainty evidence) and one trial (62 participants) reported no difference in the emergence of antibiotic-resistant organisms (very low-certainty evidence).

AUTHORS' CONCLUSIONS

We identified only low- or very low-certainty evidence to judge the effectiveness of inhaled antibiotics for the treatment of pulmonary exacerbations in people with cystic fibrosis. The included trials were not sufficiently powered to achieve their goals. Hence, we are unable to demonstrate whether one treatment was superior to the other or not. Further research is needed to establish whether inhaled tobramycin may be used as an alternative to intravenous tobramycin for some pulmonary exacerbations.

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.

Progress in precision medicine in cystic fibrosis: a focus on CFTR modulator therapy

The genetic multisystem condition cystic fibrosis (CF) has seen a paradigm shift in therapeutic approaches within the past decade. Since the first clinical descriptions in the 1930s, treatment advances had focused on the downstream consequences of a dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) chloride ion channel. The discovery of the gene that codes for CFTR and an understanding of the way in which different genetic mutations lead to disruption of normal CFTR function have led to the creation and subsequent licensing of drugs that target this process. This marks an important move towards precision medicine in CF and results from clinical trials and real-world clinical practice have been impressive. In this review we outline how CFTR modulator drugs restore function to the CFTR protein and the progress that is being made in this field. We also describe the real-world impact of CFTR modulators on both pulmonary and multisystem complications of CF and what this will mean for the future of CF care.

CFTR modulator drugs target the underlying cellular defect in cystic fibrosis. They have a range of pulmonary and multisystem effects and are leading to a transformation of care for a majority of people with cystic fibrosis.https://bit.ly/3nfEt8i

Inhaled Medicines: Past, Present, and Future

The purpose of this review is to summarize essential pharmacological, pharmaceutical, and clinical aspects in the field of orally inhaled therapies that may help scientists seeking to develop new products. After general comments on the rationale for inhaled therapies for respiratory disease, the focus is on products approved approximately over the last half a century. The organization of these sections reflects the key pharmacological categories. Products for asthma and chronic obstructive pulmonary disease include β -2 receptor agonists, muscarinic acetylcholine receptor antagonists, glucocorticosteroids, and cromones as well as their combinations. The antiviral and antibacterial inhaled products to treat respiratory tract infections are then presented. Two "mucoactive" products-dornase α and mannitol, which are both approved for patients with cystic fibrosis-are reviewed. These are followed by sections on inhaled prostacyclins for pulmonary arterial hypertension and the challenging field of aerosol surfactant inhalation delivery, especially for prematurely born infants on ventilation support. The approved products for systemic delivery via the lungs for diseases of the central nervous system and insulin for diabetes are also discussed. New technologies for drug delivery by inhalation are analyzed, with the emphasis on those that would likely yield significant improvements over the technologies in current use or would expand the range of drugs and diseases treatable by this route of administration. SIGNIFICANCE STATEMENT: This review of the key aspects of approved orally inhaled drug products for a variety of respiratory diseases and for systemic administration should be helpful in making judicious decisions about the development of new or improved inhaled drugs. These aspects include the choices of the active ingredients, formulations, delivery systems suitable for the target patient populations, and, to some extent, meaningful safety and efficacy endpoints in clinical trials.

Combining Ivacaftor and Intensive Antibiotics Achieves Limited Clearance of Cystic Fibrosis Infections

Drugs called CFTR modulators improve the physiologic defect underlying cystic fibrosis (CF) and alleviate many disease manifestations. However, studies to date indicate that chronic lung infections that are responsible for most disease-related mortality generally persist. Here, we investigated whether combining the CFTR modulator ivacaftor with an intensive 3.5-month antibiotic course could clear chronic Pseudomonas aeruginosa or Staphylococcus aureus lung infections in subjects with R117H-CFTR, who are highly ivacaftor-responsive. Ivacaftor alone improved CFTR activity, and lung function and inflammation within 48 h, and reduced P. aeruginosa and S. aureus pathogen density by ∼10-fold within a week. Antibiotics produced an additional ∼10-fold reduction in pathogen density, but this reduction was transient in subjects who remained infected. Only 1/5 P. aeruginosa-infected and 1/7 S. aureus-infected subjects became persistently culture-negative after the combined treatment. Subjects appearing to clear infection did not have particularly favorable baseline lung function or inflammation, pathogen density or antibiotic susceptibility, or bronchiectasis scores on CT scans, but they did have remarkably low sweat chloride values before and after ivacaftor. All persistently P. aeruginosa-positive subjects remained infected by their pretreatment strain, whereas subjects persistently S. aureus-positive frequently lost and gained strains. This work suggests chronic CF infections may resist eradication despite marked and rapid modulator-induced improvements in lung infection and inflammation parameters and aggressive antibiotic treatment.

Deposition of Inhaled Levofloxacin in Cystic Fibrosis Lungs Assessed by Functional Respiratory Imaging

Pulmonary infections caused by Pseudomonas aeruginosa (PA) represent the leading cause of pulmonary morbidity in adults with cystic fibrosis (CF). In addition to tobramycin, colistin, and aztreonam, levofloxacin has been approved in Europe to treat PA infections. Nevertheless, no lung deposition data on inhaled levofloxacin are yet available. We conducted a Functional Respiratory Imaging (FRI) study to predict the lung deposition of levofloxacin in the lungs of patients with CF. Three-dimensional airway models were digitally reconstructed from twenty high-resolution computed tomography scans obtained from historical patients' records. Levofloxacin aerosols generated with the corresponding approved nebuliser were characterised according to pharmacopeia. The obtained data were used to inform a computational fluid dynamics simulation of levofloxacin lung deposition using breathing patterns averaged from actual CF patients' spirometry data. Levofloxacin deposition in the lung periphery was significantly reduced by breathing patterns with low inspiratory times and high inspiratory flow rates. The intrathoracic levofloxacin deposition percentages for moderate and mild CF lungs were, respectively, 37.0% ± 13.6 and 39.5% ± 12.9 of the nominal dose. A significant albeit modest correlation was found between the central-to-peripheral deposition (C/P) ratio of levofloxacin and FEV1. FRI analysis also detected structural differences between mild and moderate CF airways. FRI revealed a significant intrathoracic deposition of levofloxacin aerosols, which distributed preferentially to the lower lung lobes, with an influence of the deterioration of FEV1 on the C/P ratio. The three-dimensional rendering of CF airways also detected structural differences between the airways of patients with mild and moderate CF.

Management of chronic Pseudomonas aeruginosa infection with inhaled levofloxacin in people with cystic fibrosis

People with cystic fibrosis (CF) are highly susceptible to bacterial infections of the airways. By adulthood, chronic Pseudomonas aeruginosa (Pa) is the most prevalent infective organism and is difficult to eradicate owing to its adaptation to the CF lung microenvironment. Long-term suppressive treatment with inhaled antimicrobials is the standard care for reducing exacerbation frequency, improving quality of life and increasing measures of lung function. Levofloxacin (a fluoroquinolone antimicrobial) has been approved as an inhaled solution in Europe and Canada, for the treatment of adults with CF with chronic P. aeruginosa pulmonary infections. Here, we review the clinical principles relating to the use of inhaled antimicrobials and inhaled levofloxacin for the management of P. aeruginosa infections in patients with CF.

Therapeutic Approach of Chronic Pseudomonas Infection in Cystic Fibrosis-A Network Meta-Analysis

Pseudomonas infection is a major determinant of morbidity and mortality in cystic fibrosis (CF). Maintaining optimal lung function in CF patients carrying Pseudomonas remains a challenge. Our study aims to investigate the efficacy of antipseudomonal inhaled antibiotics in CF patients with chronic Pseudomonas infection. A Bayesian network meta-analysis of randomized controlled trials was conducted. The main outcomes were changes in: (a) forced respiratory volume (FEV1), (b) Pseudomonas aeruginosa sputum density, and (c) CF Questionnaire Revised Respiratory Symptom Score (CFQR-RSS) at 4 weeks follow-up. Eighteen trials which reported on treatment with aztreonam lysine, tobramycin, colistin, levofloxacin, fosfomycin/tobramycin, and amikacin in various dosages were eligible for inclusion. In terms of change in FEV1%, aztreonam lysine (t.i.d., 75 mg) with a 28-day run in the tobramycin phase, aztreonam lysine (b.i.d., 75 mg) with a 28-day run in the tobramycin phase had the highest probability of being the most effective treatment (SUCRAs were 77, 76%, respectively). Regarding change in Pseudomonas sputum density, aztreonam lysine (b.i.d., 75 mg) with a 28-day run in the tobramycin phase, aztreonam lysine (t.i.d., 75 mg) with a 28-day run in the tobramycin phase had the highest probability of being the most effective treatment (SUCRAs were 90, 86%, respectively). Regarding change in CFQR-RSS, aztreonam lysine (t.i.d., 75 mg) and aztreonam lysine (b.i.d., 75 mg) with a 28-day run in the tobramycin inhalation solution phase had the highest probability of being the most effective treatments (SUCRA:74% and 72%, respectively). Regarding changes in FEV1% and Pseudomonas sputum density, aztreonam lysine with a run in tobramycin phase may be the best treatment option in treating chronic Pseudomonas in CF. According to CFQR-RSS no significant differences were found. Given the limitations of the studies included, validation trials are called for.

[Multidisciplinary Management of Non-cystic-fibrosis Bronchiectasis - State of the Art]

Bronchiectasis is a mostly irreversible bronchial dilatation induced by a destruction of elastic and muscular fibers of the bronchial wall. Radiological criteria of bronchiectasis are met, when the inner diameter of the bronchial wall surpasses the outer diameter of the accompanying pulmonary artery. Its incidence increases with age, even though it often lacks true clinical signs of disease. Only when it is accompanied by cough, expectorations and recurring bronchopulmonary infections, it can be considered a true bronchiectatic disease. Cystic fibrosis (CF) is one of its preeminent triggers, but certainly plays a particular role in this entity, which is why the terminus of "non-CF-bronchiectasis" was coined in the first place.Multidisciplinary management consists in extensive diagnostic work-up, treatment of potential triggers of bronchiectasis and supportive care in form of vaccination programs, secretolysis and pulmonary rehabilitation, as well as antibiotic treatment of pulmonary exacerbations.Surgical treatment has to be considered a last resort in case of hemoptysis, recurring severe pneumonia or secondary aspergilloma with complete resection of all pathological findings, ideally by minimally-invasive approach.

Clinical impact of levofloxacin inhalation solution in cystic fibrosis patients in a real-world setting

BACKGROUND

Levofloxacin inhalation solution is the most recently approved inhaled antibiotic in Europe and Canada for adult cystic fibrosis patients. Its efficacy and safety have been assessed in randomized controlled trials. Our aim was to evaluate real life experience and outcomes in our treatment centre.

METHODS

We evaluated the efficacy of inhaled levofloxacin solution in 86 patients with cystic fibrosis in terms of the following outcome parameters: changes in %-predicted forced expiratory volume in one second (FEV₁), body-mass index (BMI), and exacerbation rate. We conducted an intraindividual analysis of patients who received levofloxacin inhalation solution twice daily 240 mg for at least 4 weeks.

RESULTS

Change in FEV₁% predicted for the treatment period was +2.27% (p=0.0027) after 4 weeks. There was no change in BMI for overall group, but exacerbation rate compared to one year before initiation of inhaled levofloxacin decreased significantly (p=0.0024) after 1 year of treatment (3.23 ± 1.39 versus 2.71 ± 1.58).

CONCLUSIONS

In patients with cystic fibrosis, inhaled levofloxacin solution has the potential to improve FEV₁ and to reduce the number of bronchopulmonary exacerbations.

Cystic Fibrosis: Recent Insights into Inhaled Antibiotic Treatment and Future Perspectives

Although new inhaled antibiotics have profoundly improved respiratory diseases in cystic fibrosis (CF) patients, lung infections are still the leading cause of death. Inhaled antibiotics, i.e., colistin, tobramycin, aztreonam lysine and levofloxacin, are used as maintenance treatment for CF patients after the development of chronic Pseudomonas aeruginosa (P. aeruginosa) infection. Their use offers advantages over systemic therapy since a relatively high concentration of the drug is delivered directly to the lung, thus, enhancing the pharmacokinetic/pharmacodynamic parameters and decreasing toxicity. Notably, alternating treatment with inhaled antibiotics represents an important strategy for improving patient outcomes. The prevalence of CF patients receiving continuous inhaled antibiotic regimens with different combinations of the anti-P. aeruginosa antibiotic class has been increasing over time. Moreover, these antimicrobial agents are also used for preventing acute pulmonary exacerbations in CF. In this review, the efficacy and safety of the currently available inhaled antibiotics for lung infection treatment in CF patients are discussed, with a particular focus on strategies for eradicating P. aeruginosa and other pathogens. Moreover, the effects of long-term inhaled antibiotic therapy for chronic P. aeruginosa infection and for the prevention of pulmonary exacerbations is reviewed. Finally, how the mucus environment and microbial community richness can influence the efficacy of aerosolized antimicrobial agents is discussed.

Impact of Pseudomonas aeruginosa Infection on Patients with Chronic Inflammatory Airway Diseases

Pseudomonas aeruginosa (P. aeruginosa) is a ubiquitous and opportunistic microorganism and is considered one of the most significant pathogens that produce chronic colonization and infection of the lower respiratory tract, especially in people with chronic inflammatory airway diseases such as asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), and bronchiectasis. From a microbiological viewpoint, the presence and persistence of P. aeruginosa over time are characterized by adaptation within the host that precludes any rapid, devastating injury to the host. Moreover, this microorganism usually develops antibiotic resistance, which is accelerated in chronic infections especially in those situations where the frequent use of antimicrobials facilitates the selection of “hypermutator P. aeruginosa strain”. This phenomenon has been observed in people with bronchiectasis, CF, and the “exacerbator” COPD phenotype. From a clinical point of view, a chronic bronchial infection of P. aeruginosa has been related to more severity and poor prognosis in people with CF, bronchiectasis, and probably in COPD, but little is known on the effect of this microorganism infection in people with asthma. The relationship between the impact and treatment of P. aeruginosa infection in people with airway diseases emerges as an important future challenge and it is the most important objective of this review.

Accelerated Approval or Risk Reduction? How Response Biomarkers Advance Therapeutics through Clinical Trials in Cystic Fibrosis

Progress in the development of new therapies for cystic fibrosis (CF) has benefited from therapeutically responsive biomarkers to streamline drug development. Paradoxically, these response biomarkers have been proven to be essential even in the presence of data demonstrating a lack of correlation with clinical outcomes across individuals with CF. This finding is unsurprising, particularly in the setting of a rare disease given complex disease processes and an often-limited pool of clinically effective therapies by which to link biomarkers and clinical responsiveness. While many response biomarkers will be unable to progress from their status as markers of biological efficacy to either established correlates of clinical efficacy or surrogate endpoints, they remain critical to the overall success of therapeutic development.

Successes and Challenges: Inhaled Treatment Approaches Using Magnetic Nanoparticles in Cystic Fibrosis

Magnetic nanoparticles have been largely applied to increase the efficacy of antibiotics due to passive accumulation provided by enhancing permeability and retention, which is essential for the treatment of lung infections. Recurring lung infections such as in the life-shortening genetic disease cystic fibrosis (CF) are a major problem. The recent advent of the CF modulator drug ivacaftor, alone or in combination with lumacaftor or tezacaftor, has enabled systemic treatment of the majority of patients. Magnetic nanoparticles (MNPs) show unique properties such as biocompatibility and biodegradability as well as magnetic and heat-medicated characteristics. These properties make them suitable to be used as drug carriers and hyperthermia-based agents. Hyperthermia is a promising approach for the thermal activation therapy of several diseases, including pulmonary diseases. The benefits of delivering CF drugs via inhalation using MNPs as drug carriers afford application of sufficient therapeutic dosages directly to the primary target site, while avoiding potential suboptimal pharmacokinetics/pharmacodynamics and minimizing the risks of systemic toxicity. This review explores the multidisciplinary approach of using MNPs as vehicles of drug delivery. Additionally, we highlight advantages such as increased drug concentration at disease site, minimized drug loss and the possibility of specific cell targeting, while addressing major challenges for this emerging field.

Control of the Lung Residence Time of Highly Permeable Molecules after Nebulization: Example of the Fluoroquinolones

Pulmonary drug delivery is a promising strategy to treat lung infectious disease as it allows for a high local drug concentration and low systemic side effects. This is particularly true for low-permeability drugs, such as tobramycin or colistin, that penetrate the lung at a low rate after systemic administration and greatly benefit from lung administration in terms of the local drug concentration. However, for relatively high-permeable drugs, such as fluoroquinolones (FQs), the rate of absorption is so high that the pulmonary administration has no therapeutic advantage compared to systemic or oral administration. Formulation strategies have thus been developed to decrease the absorption rate and increase FQs’ residence time in the lung after inhalation. In the present review, some of these strategies, which generally consist of either decreasing the lung epithelium permeability or decreasing the release rate of FQs into the epithelial lining fluid after lung deposition, are presented in regards to their clinical aspects.

Clinical Management of Respiratory Adverse Events Associated With Amikacin Liposome Inhalation Suspension: Results From a Patient Survey

Patients with Mycobacterium avium complex lung disease treated with amikacin liposome inhalation suspension (ALIS) at 2 clinics in the United States were surveyed to assess the frequency and management of ALIS-associated respiratory adverse events. Most respondents experienced these events, but management through physician-guided measures (eg, bronchodilator use, oral rinses, and/or temporary dosing adjustments) resulted in symptomatic improvement.

Off-label use of intravenous antimicrobials for inhalation in patients with cystic fibrosis

Management of infections in patients with cystic fibrosis (CF) presents challenges for healthcare providers, including the eradication of initial acquisition, treatment of acute exacerbations, and chronic infection with suppressive therapy. Inhaled antimicrobial therapy for infections in patients with CF has been used in these capacities, often in an effort to achieve optimal concentrations in sputum for antimicrobial efficacy while mitigating potential toxicities associated with systemic therapy. Unfortunately, there are few commercially available products formulated for inhalation, resulting in the off-label use of other formulations, such as intravenous products, administered via nebulization. This review aims to examine the evidence supporting the efficacy of these off-label formulations for management of acute and chronic infections associated with CF, as well as adverse effects associated with their use.

Efficacy of Ciprofloxacin and Its Copper Complex against Pseudomonas aeruginosa Biofilms

A limitation of antibiotic treatments for P. aeruginosa (PA) chronic pulmonary infections is the reduced efficacy due to sub-therapeutic concentrations at the infection site and the development of biofilm. A novel approach to sustain ciprofloxacin (CIP) in the lungs after inhalation is to reduce its pulmonary absorption rate by its complexation with copper (CIP-Cu). This study aimed to evaluate the antimicrobial action of cationic CIP-Cu complex in PA biofilms in terms of drug concentration and time. Two PA strains, PA01 and PA14, were grown to form biofilm layers in equilibrium with planktonic cells. Static parameters such as pyoverdine production by planktonic cells, enzymatic activity within biofilms, and biofilm biomass 24 h after the addition of CIP or CIP-Cu were evaluated. Also, the kinetic effects of CIP and CIP-Cu on biofilms were evaluated by bioluminescence kinetics using transgenic strains. No differences were observed between CIP and CIP-Cu in terms of efficacy against biofilms, validating the potential of using this complex to treat PA biofilms. Interestingly, CIP concentrations slightly below the MIC value against planktonic bacteria stimulated both virulence and biofilm PA01 production. These results support the need to accurately achieve high CIP concentration in the lungs, which can be more easily achieved by pulmonary delivery of advanced CIP formulations (CIP-metal complexes or liposomal CIP) instead of the oral administration of free CIP.

Inhaled antibiotics for pulmonary exacerbations in cystic fibrosis

BACKGROUND

Cystic fibrosis is a genetic disorder in which abnormal mucus in the lungs is associated with susceptibility to persistent infection. Pulmonary exacerbations are when symptoms of infection become more severe. Antibiotics are an essential part of treatment for exacerbations and inhaled antibiotics may be used alone or in conjunction with oral antibiotics for milder exacerbations or with intravenous antibiotics for more severe infections. Inhaled antibiotics do not cause the same adverse effects as intravenous antibiotics and may prove an alternative in people with poor access to their veins. This is an update of a previously published review.

OBJECTIVES

To determine if treatment of pulmonary exacerbations with inhaled antibiotics in people with cystic fibrosis improves their quality of life, reduces time off school or work and improves their long-term survival.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Group's Cystic Fibrosis Trials Register. Date of the last search: 03 October 2018.We searched ClinicalTrials.gov, the Australia and New Zealand Clinical Trials Registry and WHO ICTRP for relevant trials. Date of last search: 09 October 2018.

SELECTION CRITERIA

Randomised controlled trials in people with cystic fibrosis with a pulmonary exacerbation in whom treatment with inhaled antibiotics was compared to placebo, standard treatment or another inhaled antibiotic for between one and four weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible trials, assessed the risk of bias in each trial and extracted data. They assessed the quality of the evidence using the GRADE criteria. Authors of the included trials were contacted for more information.

MAIN RESULTS

Four trials with 167 participants are included in the review. Two trials (77 participants) compared inhaled antibiotics alone to intravenous antibiotics alone and two trials (90 participants) compared a combination of inhaled and intravenous antibiotics to intravenous antibiotics alone. Trials were heterogenous in design and two were only available in abstract form. Risk of bias was difficult to assess in most trials, but for all trials we judged there to be a high risk from lack of blinding and an unclear risk with regards to randomisation. Results were not fully reported and only limited data were available for analysis.Inhaled antibiotics alone versus intravenous antibiotics aloneOnly one trial (n = 18) reported a perceived improvement in lifestyle (quality of life) in both groups (very low-quality of evidence). Neither trial reported on time off work or school. Both trials measured lung function, but there was no difference reported between treatment groups (very low-quality evidence). With regards to our secondary outcomes, one trial (n = 18) reported no difference in the need for additional antibiotics and the second trial (n = 59) reported on the time to next exacerbation. In neither case was a difference between treatments identified (both very low-quality evidence). The single trial (n = 18) measuring adverse events and sputum microbiology did not observe any in either treatment group for either outcome (very low-quality evidence).Inhaled antibiotics plus intravenous antibiotics versus intravenous antibiotics aloneNeither trial reported on quality of life or time off work or school. Both trials measured lung function, but found no difference between groups in forced expiratory volume in one second (one trial, n = 28, very low-quality evidence) or vital capacity (one trial, n = 62). Neither trial reported on the need for additional antibiotics or the time to the next exacerbation; however, one trial (n = 28) reported on hospital admissions and found no difference between groups. Both trials reported no difference between groups in adverse events (very low-quality evidence) and one trial (n = 62) reported no difference in the emergence of antibiotic-resistant organisms (very low-quality evidence).

AUTHORS' CONCLUSIONS

There is little useful high-level evidence to judge the effectiveness of inhaled antibiotics for the treatment of pulmonary exacerbations in people with cystic fibrosis. The included trials were not sufficiently powered to achieve their goals. Hence, we are unable to demonstrate whether one treatment was superior to the other or not. Further research is needed to establish whether inhaled tobramycin may be used as an alternative to intravenous tobramycin for some pulmonary exacerbations.

Innovating cystic fibrosis clinical trial designs in an era of successful standard of care therapies

PURPOSE OF REVIEW

Evolving cystic fibrosis 'standards of care' have influenced recent cystic fibrosis clinical trial designs for new therapies; care additions/improvements will require innovative trial designs to maximize feasibility and efficacy detection.

RECENT FINDINGS

Three cystic fibrosis therapeutic areas (pulmonary exacerbations, Pseudomonas aeruginosa airway infections, and reduced cystic fibrosis transmembrane conductance regulator [CFTR] protein function) differ with respect to the duration for which recognized 'standards of care' have been available. However, developers of new therapies in all the three areas are affected by similar challenges: standards of care have become so strongly entrenched that traditional placebo-controlled studies in cystic fibrosis populations likely to benefit from newer therapies have become less and less feasible. Today, patients/clinicians are more likely to entertain participation in active-comparator trial designs, that have substantial challenges of their own. Foremost among these are the selection of 'valid' active comparator(s), estimation of a comparator's current clinical efficacy (required for testing noninferiority hypotheses), and effective blinding of commercially available comparators.

SUMMARY

Recent and future cystic fibrosis clinical trial designs will have to creatively address this collateral result of successful past development of effective cystic fibrosis therapies: patients and clinicians are much less likely to accept simple, placebo-controlled studies to evaluate future therapies.

Inhaled anti-pseudomonal antibiotics for long-term therapy in cystic fibrosis

BACKGROUND

Inhaled antibiotics are commonly used to treat persistent airway infection with Pseudomonas aeruginosa that contributes to lung damage in people with cystic fibrosis. Current guidelines recommend inhaled tobramycin for individuals with cystic fibrosis and persistent Pseudomonas aeruginosa infection who are aged six years or older. The aim is to reduce bacterial load in the lungs so as to reduce inflammation and deterioration of lung function. This is an update of a previously published review.

OBJECTIVES

To evaluate the effects long-term inhaled antibiotic therapy in people with cystic fibrosis on clinical outcomes (lung function, frequency of exacerbations and nutrition), quality of life and adverse events (including drug sensitivity reactions and survival).

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched ongoing trials registries.Date of last search: 13 February 2018.

SELECTION CRITERIA

We selected trials if inhaled anti-pseudomonal antibiotic treatment was used for at least three months in people with cystic fibrosis, treatment allocation was randomised or quasi-randomised, and there was a control group (either placebo, no placebo or another inhaled antibiotic).

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, judged the risk of bias, extracted data from these trials and judged the quality of the evidence using the GRADE system.

MAIN RESULTS

The searches identified 333 citations to 98 trials; 18 trials (3042 participants aged between five and 56 years) met the inclusion criteria. Limited data were available for meta-analyses due to the variability of trial design and reporting of results. A total of 11 trials (1130 participants) compared an inhaled antibiotic to placebo or usual treatment for a duration between three and 33 months. Five trials (1255 participants) compared different antibiotics, two trials (585 participants) compared different regimens of tobramycin and one trial (90 participants) compared intermittent tobramycin with continuous tobramycin alternating with aztreonam. One of the trials (18 participants) compared to placebo and a different antibiotic and so fell into both groups. The most commonly studied antibiotic was tobramycin which was studied in 12 trials.We found limited evidence that inhaled antibiotics improved lung function (four of the 11 placebo-controlled trials, n = 814). Compared to placebo, inhaled antibiotics also reduced the frequency of exacerbations (three trials, n = 946), risk ratio 0.66 (95% confidence interval (CI) 0.47 to 0.93). There were insufficient data for us to be able to report an effect on nutritional outcomes or survival and there were insufficient data for us to ascertain the effect on quality of life. There was no significant effect on antibiotic resistance seen in the two trials that were included in meta-analyses. Tinnitus and voice alteration were the only adverse events significantly more common in the inhaled antibiotics group. The overall quality of evidence was deemed to be low for most outcomes due to risk of bias within the trials and imprecision due to low event rates.Of the eight trials that compared different inhaled antibiotics or different antibiotic regimens, there was only one trial in each comparison. Forced expiratory volume at one second (FEV₁) % predicted was only found to be significantly improved with aztreonam lysine for inhalation compared to tobramycin (n = 273), mean difference -3.40% (95% CI -6.63 to -0.17). However, the method of defining the endpoint was different to the remaining trials and the participants were exposed to tobramycin for a long period making interpretation of the results problematic. No significant differences were found in the remaining comparisons with regard to lung function. Pulmonary exacerbations were measured in different ways, but one trial (n = 273) found that the number of people treated with antibiotics was lower in those receiving aztreonam than tobramycin, risk ratio 0.66 (95% CI 0.51 to 0.86). We found the quality of evidence for these comparisons to be directly related to the risk of bias within the individual trials and varied from low to high.

AUTHORS' CONCLUSIONS

Inhaled anti-pseudomonal antibiotic treatment probably improves lung function and reduces exacerbation rate, but pooled estimates of the level of benefit were very limited. The best evidence is for inhaled tobramycin. More evidence from trials measuring similar outcomes in the same way is needed to determine a better measure of benefit. Longer-term trials are needed to look at the effect of inhaled antibiotics on quality of life, survival and nutritional outcomes.

Antimicrobial molecules in the lung: formulation challenges and future directions for innovation

Inhaled antimicrobials have been extremely beneficial in treating respiratory infections, particularly chronic infections in a lung with cystic fibrosis. The pulmonary delivery of antibiotics has been demonstrated to improve treatment efficacy, reduce systemic side effects and, critically, reduce drug exposure to commensal bacteria compared with systemic administration, reducing selective pressure for antimicrobial resistance. This review will explore the specific challenges of pulmonary delivery of a number of differing antimicrobial molecules, and the formulation and technological approaches that have been used to overcome these difficulties. It will also explore the future challenges being faced in the development of inhaled products and respiratory infection treatment, and identify future directions of innovation, with a particular focus on respiratory infections caused by multiple drug-resistant pathogens.

Investigational inhaled therapies for non-CF bronchiectasis

INTRODUCTION

Bronchiectasis not related to cystic fibrosis (non-CF bronchiectasis) are associated with a high unmet therapeutic need due to the lack of specifically authorized medications, especially via the inhalation route. In non-CF bronchiectasis chronic infection with Pseudomonas aeruginosa is common and favored by the persistent local inflammation and viscid sputum production. Therefore inhaled antibiotics, mucolytics or anti-inflammatory agents could represent appropriate therapeutic interventions in this setting.

AREAS COVERED

This review herein discusses the inhaled therapies currently under investigation for non-CF bronchiectasis and their potential therapeutic positioning in exacerbation versus stable state.

EXPERT OPINION

Inhaled antipseudomonal antibiotics are of promising efficacy, but further efforts should also be made to detect bactericidal approaches against Burkholderia cepacia complex, and to interfere chronic inflammation topically.

Understanding Pseudomonas status among adults with cystic fibrosis: a real-world comparison of the Leeds criteria against clinicians' decision

Pseudomonas aeruginosa status influences cystic fibrosis (CF) clinical management but no 'gold standard' definition exists. The Leeds criteria are commonly used but may lack sensitivity for chronic P. aeruginosa. We compared clinicians' decision with the Leeds criteria in three adult CF centres. Two independent prospective datasets (Sheffield dataset, n = 185 adults; ACtiF pilot dataset, n = 62 adults from two different centres) were analysed. Clinicians involved in deciding P. aeruginosa status were blinded to the study objectives. Clinicians considered more adults with CF to have chronic P. aeruginosa infection compared to the Leeds criteria. This was more so for the Sheffield dataset (106/185, 57.3% with clinicians' decision vs. 80/185, 43.2% with the Leeds criteria; kappa coefficient between these two methods 0.72) compared to the ACtiF pilot dataset (34/62, 54.8% with clinicians' decision vs. 30/62, 48.4% with the Leeds criteria; kappa coefficient between these two methods 0.82). However, clinicians across different centres were relatively consistent once age and severity of lung disease, as indicated by the type of respiratory samples provided, were taken into account. Agreement in P. aeruginosa status was similar for both datasets among adults who predominantly provided sputum samples (kappa coefficient 0.78) or adults > 25 years old (kappa coefficient 0.82). Across three different centres, clinicians did not always agree with the Leeds criteria and tended to consider the Leeds criteria to lack sensitivity. Where disagreement occurred, clinicians tended to diagnose chronic P. aeruginosa infection because other relevant information was considered. These results suggest that a better definition for chronic P. aeruginosa might be developed by using consensus methods to move beyond a definition wholly dependent on standard microbiological results.

[Criteria for treating MRSA in sputum]

Methicillin-resistant strains of Staphylococcus aureus (MRSA) are of particular significance for the management of patients with airway infections, since the disease course is often complicated and treatment rendered difficult by multiple resistance. Their prevalence is now slowly declining, but still alarmingly high. Hospital-acquired infections are predominant, but hospital-associated and community-acquired infections do occur, as do rare infections with livestock-acquired strains. Non-nosocomial strains are characterized by different pathogenic factors and a different spectrum of antibacterial resistance; they often have a threatening disease course. Anti-infectives with activity against MRSA are unusual and have particular toxicity profiles. On the other hand, MRSA colonization is eliminated spontaneously in healthy people and acute bronchitis is treatable by common oral antibiotics. However, chronic airway infection in bronchiectasis and other forms of structural airway damage requires a complex systemic and local treatment approach for pathogen elimination.

Highlights from the 2016 North American Cystic Fibrosis Conference

The 30th annual North American Cystic Fibrosis Conference (NACFC) was held in Orlando, FL, on October 27-29, 2016. Abstracts were published in a supplement to Pediatric Pulmonology. This review summarizes several major topic areas addressed at the conference: the pathophysiology of cystic fibrosis (CF) lung disease, clinical trials, clinical management issues, and quality improvement. We sought to provide an overview of emerging concepts in several areas of CF research and care, rather than a comprehensive review of the conference. Citations from the conference are by first author and abstract number or symposium number, as designated in the supplement.

The treatment of the pulmonary and extrapulmonary manifestations of cystic fibrosis

Cystic fibrosis (CF) is a complex multisystem disease with considerable between patient variability in its manifestations and severity. In the past several decades, the range of treatments and the evidence to support their use for the pulmonary and extrapulmonary manifestations of CF have increased dramatically, contributing to the improved median survival of patients. As therapy for CF has evolved, new challenges including treatment adherence, medication intolerance and allergy, medical complications and coping with the burden of disease in the context of having a family and managing employment have arisen. While the majority of current therapy focuses primarily on improving symptoms, new therapies (CFTR modulators) target the underlying genetic defect.

Inhaled Antibiotic Therapy in Chronic Respiratory Diseases

The management of patients with chronic respiratory diseases affected by difficult to treat infections has become a challenge in clinical practice. Conditions such as cystic fibrosis (CF) and non-CF bronchiectasis require extensive treatment strategies to deal with multidrug resistant pathogens that include Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus, Burkholderia species and non-tuberculous Mycobacteria (NTM). These challenges prompted scientists to deliver antimicrobial agents through the pulmonary system by using inhaled, aerosolized or nebulized antibiotics. Subsequent research advances focused on the development of antibiotic agents able to achieve high tissue concentrations capable of reducing the bacterial load of difficult-to-treat organisms in hosts with chronic respiratory conditions. In this review, we focus on the evidence regarding the use of antibiotic therapies administered through the respiratory system via inhalation, nebulization or aerosolization, specifically in patients with chronic respiratory diseases that include CF, non-CF bronchiectasis and NTM. However, further research is required to address the potential benefits, mechanisms of action and applications of inhaled antibiotics for the management of difficult-to-treat infections in patients with chronic respiratory diseases.

Antibiotic strategies for eradicating Pseudomonas aeruginosa in people with cystic fibrosis

BACKGROUND

Respiratory tract infection with Pseudomonas aeruginosa occurs in most people with cystic fibrosis. Once chronic infection is established, Pseudomonas aeruginosa is virtually impossible to eradicate and is associated with increased mortality and morbidity. Early infection may be easier to eradicate.This is an update of a Cochrane review first published in 2003, and previously updated in 2006, 2009 and 2014.

OBJECTIVES

To determine whether antibiotic treatment of early Pseudomonas aeruginosa infection in children and adults with cystic fibrosis eradicates the organism, delays the onset of chronic infection, and results in clinical improvement. To evaluate whether there is evidence that a particular antibiotic strategy is superior to or more cost-effective than other strategies and to compare the adverse effects of different antibiotic strategies (including respiratory infection with other micro-organisms).

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Most recent search: 10 October 2016.

SELECTION CRITERIA

We included randomised controlled trials of people with cystic fibrosis, in whom Pseudomonas aeruginosa had recently been isolated from respiratory secretions. We compared combinations of inhaled, oral or intravenous antibiotics with placebo, usual treatment or other combinations of inhaled, oral or intravenous antibiotics. We excluded non-randomised trials, cross-over trials, and those utilising historical controls.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed risk of bias and extracted data.

MAIN RESULTS

The search identified 60 trials; seven trials (744 participants) with a duration between 28 days and 27 months were eligible for inclusion. Three of the trials are over 10 years old and their results may be less applicable today given the changes in standard treatment. Some of the trials had low numbers of participants and most had relatively short follow-up periods; however, there was generally a low risk of bias from missing data. In most trials it was difficult to blind participants and clinicians to treatment given the interventions and comparators used. Two trials were supported by the manufacturers of the antibiotic used.Evidence from two trials (38 participants) at the two-month time-point showed treatment of early Pseudomonas aeruginosa infection with inhaled tobramycin results in microbiological eradication of the organism from respiratory secretions more often than placebo, odds ratio 0.15 (95% confidence interval (CI) 0.03 to 0.65) and data from one of these trials, with longer follow up, suggested that this effect may persist for up to 12 months.One randomised controlled trial (26 participants) compared oral ciprofloxacin and nebulised colistin versus usual treatment. Results after two years suggested treatment of early infection results in microbiological eradication of Pseudomonas aeruginosa more often than no anti-pseudomonal treatment, odds ratio 0.12 (95% CI 0.02 to 0.79).One trial comparing 28 days to 56 days treatment with nebulised tobramycin solution for inhalation in 88 participants showed that both treatments were effective and well-tolerated, with no notable additional improvement with longer over shorter duration of therapy. However, this trial was not powered to detect non-inferiority or equivalence .A trial of oral ciprofloxacin with inhaled colistin versus nebulised tobramycin solution for inhalation alone (223 participants) failed to show a difference between the two strategies, although it was underpowered to show this. A further trial of inhaled colistin with oral ciprofloxacin versus nebulised tobramycin solution for inhalation with oral ciprofloxacin also showed no superiority of the former, with increased isolation of Stenotrophomonas maltophilia in both groups.A recent, large trial in 306 children aged between one and 12 years compared cycled nebulised tobramycin solution for inhalation to culture-based therapy and also ciprofloxacin to placebo. The primary analysis showed no difference in time to pulmonary exacerbation or proportion of Pseudomonas aeruginosa positive cultures. An analysis performed in this review (not adjusted for age) showed fewer participants in the cycled therapy group with one or more isolates of Pseudomonas aeruginosa, odds ratio 0.51 (95% CI 0.31 to 0.28). Using GRADE, the quality of evidence for outcomes was downgraded to moderate to very low. Downgrading decisions for Pseudomonas aeruginosa eradication and lung function were based on applicability (participants mostly children) and limitations in study design, with imprecision an additional limitation for lung function, growth parameters and adverse effects.

AUTHORS' CONCLUSIONS

We found that nebulised antibiotics, alone or in combination with oral antibiotics, were better than no treatment for early infection with Pseudomonas aeruginosa. Eradication may be sustained for up to two years. There is insufficient evidence to determine whether antibiotic strategies for the eradication of early Pseudomonas aeruginosa decrease mortality or morbidity, improve quality of life, or are associated with adverse effects compared to placebo or standard treatment. Four trials comparing two active treatments have failed to show differences in rates of eradication of Pseudomonas aeruginosa. There have been no published randomised controlled trials that investigate the efficacy of intravenous antibiotics to eradicate Pseudomonas aeruginosa in cystic fibrosis. Overall, there is still insufficient evidence from this review to state which antibiotic strategy should be used for the eradication of early Pseudomonas aeruginosa infection in cystic fibrosis.

Antibiotic treatment of biofilm infections

Bacterial biofilms are associated with a wide range of infections, from those related to exogenous devices, such as catheters or prosthetic joints, to chronic tissue infections such as those occurring in the lungs of cystic fibrosis patients. Biofilms are recalcitrant to antibiotic treatment due to multiple tolerance mechanisms (phenotypic resistance). This causes persistence of biofilm infections in spite of antibiotic exposure which predisposes to antibiotic resistance development (genetic resistance). Understanding the interplay between phenotypic and genetic resistance mechanisms acting on biofilms, as well as appreciating the diversity of environmental conditions of biofilm infections which influence the effect of antibiotics are required in order to optimize the antibiotic treatment of biofilm infections. Here, we review the current knowledge on phenotypic and genetic resistance in biofilms and describe the potential strategies for the antibiotic treatment of biofilm infections. Of note is the optimization of PK/PD parameters in biofilms, high-dose topical treatments, combined and sequential/alternate therapies or the use antibiotic adjuvants.

[Infections in cystic fibrosis: Up-to-date]

This review focused on the news in CF airways infection. International guidelines were provided for the care of non tuberculous mycobacteria, and recent studies stressed on the benefit effect of azithromycin or combined antibiotics. The identification of multiresistant environmental bacteria in airways made to account for little-known consequences. Early diagnosis and eradication of Pseudomonas aeruginosa and Staphylococcus aureus methi-R were still a concern, and reports were proposed. However, the studies on staphylococcus methi-R should be interpreted as regards the European or American continent. Thus, levofloxacine has demonstrated its efficacy without enhancing the efficiency. This drug will increase the choice for treating the patient, but no study were provided on the expected modification of the patient microbiota and the known risk of emergent resistance to antibiotics. Lastly, this review underlined that the CF practitioner was encouraged to search and not underestimate the presence of fungus, of which the not so well studied Aspergillus fumigatus.

Comparison of the anti-inflammatory effects of fluorometholone 0.1% combined with levofloxacin 0.5% and tobramycin/dexamethasone eye drops after cataract surgery

AIM

To compare the combination of fluorometholone 0.1% and levofloxacin 0.5% to tobramycin/dexamethasone eye drops in controlling inflammation and preventing infection after phacoemulsification with an intraocular lens implantation.

METHODS

Sixty eyes from 60 patients undergoing cataract phacoemulsification were randomized into two groups; half of the patients were treated with fluorometholone (6 times/d) combined with levofloxacin (4 times/d), while the other half were treated with tobramycin/dexamethasone (4 times/d) eye drops for one week. Preoperative and postoperative intraocular pressure, aqueous flare, corneal thickness, and signs and symptoms were recorded before the operation and 1wk following treatments.

RESULTS

There were no statistically significant differences between the two groups in corneal thickness (P≥0.629), aqueous flare (P≥0.398), and signs and symptoms scores (P≥0.350) at each time point. Ocular hypertension was only observed in two eyes in the tobramycin/dexamethasone group.

CONCLUSION

Fluorometholone combined with levofloxacin treatment shows comparable efficacy but without the tendency to increase intraocular pressure; thus, it might be a better regimen for postoperative use.

Biomarkers for cystic fibrosis drug development

PURPOSE

To provide a review of the status of biomarkers in cystic fibrosis drug development, including regulatory definitions and considerations, a summary of biomarkers in current use with supportive data, current gaps, and future needs.

METHODS

Biomarkers are considered across several areas of CF drug development, including cystic fibrosis transmembrane conductance regulator modulation, infection, and inflammation.

RESULTS

Sweat chloride, nasal potential difference, and intestinal current measurements have been standardized and examined in the context of multicenter trials to quantify CFTR function. Detection and quantification of pathogenic bacteria in CF respiratory cultures (e.g.: Pseudomonas aeruginosa) are commonly used in early phase antimicrobial clinical trials, and to monitor safety of therapeutic interventions. Sputum (e.g.: neutrophil elastase, myeloperoxidase, calprotectin) and blood biomarkers (e.g.: C reactive protein, calprotectin, serum amyloid A) have had variable success in detecting response to inflammatory treatments.

CONCLUSIONS

Biomarkers are used throughout the drug development process in CF, and many have been used in early phase clinical trials to provide proof of concept, detect drug bioactivity, and inform dosing for later-phase studies. Advances in the precision of current biomarkers, and the identification of new biomarkers with 'omics-based technologies, are needed to accelerate CF drug development.

Managing Pseudomonas aeruginosa respiratory infections in cystic fibrosis

PURPOSE OF REVIEW

The current guidelines and recent clinical research in the management of Pseudomonas aeruginosa respiratory infections in cystic fibrosis (CF) are reviewed. Areas where further research is required will also be highlighted.

RECENT FINDINGS

P. aeruginosa is a key respiratory pathogen in CF. Inhaled tobramycin or colistin is recommended for early eradication to prevent establishment of chronic infection. Other antibiotic options are currently being investigated. The long-term success of eradication strategies is also now being assessed. The use of inhaled antibiotics in the management of chronic P. aeruginosa infection is an area of active investigation. Acute pulmonary exacerbations are still a major cause of morbidity and mortality. Guidelines continue to recommend combination intravenous therapy but further research is required to clarify the advantage of this approach. Multidrug resistance is common and potentially more effective antipseudomonal antibiotics may soon become available.

SUMMARY

The management of P. aeruginosa respiratory infection in CF remains a challenging area, especially in the setting of multidrug resistance. The role of inhaled antibiotics continues to be expanded. Further research is required in the key areas of eradication and management of chronic infection and acute pulmonary exacerbations to identify those treatments that optimize long-term, clinical benefits.

Effect of pulmonary exacerbations treated with oral antibiotics on clinical outcomes in cystic fibrosis

BACKGROUND

Despite extensive knowledge regarding the effect of pulmonary exacerbations treated with intravenous antibiotics on clinical outcomes in cystic fibrosis (CF), there is little known about the role of milder pulmonary exacerbations treated with oral antibiotics (oPEx).

METHODS

This was a retrospective cohort study of patients with CF followed at the Hospital for Sick Children and St. Michael's Hospital from 2009 to 2014. We evaluated the effect of oPEx on short-term clinical outcomes as the proportion of oPEx events in which 100% or 90% of baseline FEV₁% predicted was recovered at the end of treatment. We then examined the association of the number of oPEx events in the past 12 months on lung function (FEV₁% predicted) and nutritional status (body mass index (BMI) z-score) using a mixed-effects model.

RESULTS

There were a total of 2608 oPEx events in 570 subjects during the study period. In over half (53.4%) of oPEx events, lung function was already at 90% or higher of baseline FEV₁ at the initiation of oral antibiotic therapy and 82% were at 90% or higher of baseline FEV₁ at follow-up. In individuals with CF, one or more oPex events in the previous 12 months were associated with decreased FEV₁ compared with 12 months periods without oPex events. When the cumulative effect of oPExs on lung function was examined over the entire study period, patients with six or more oPEx events had the steepest rate of FEV₁ decline. oPEx events were not associated with changes in BMI.

CONCLUSIONS

oPEx events are associated with short-term loss of FEV₁ and have a negative effect on lung function over time.

Pediatric Pulmonology year in review 2015: Part 4

In this article, we highlight cystic fibrosis (CF) research published in Pediatric Pulmonology during 2015. Articles from other journals that reflect similar themes, and those of special importance, are also included. Pediatr Pulmonol. 2016;51:754-765. © 2016 Wiley Periodicals, Inc.

Current and future treatment options for cystic fibrosis lung disease: latest evidence and clinical implications

Treatment for cystic fibrosis (CF) has conventionally targeted downstream consequences of the defect such as mucus plugging and infection. More recently, significant advances have been made in treating the root cause of the disease, namely a defective CF transmembrane conductance regulator (CFTR) gene. This review summarizes current pulmonary treatment options and highlights advances in research and development of new therapies.

New drug developments in the management of cystic fibrosis lung disease

INTRODUCTION

Therapies for cystic fibrosis (CF) pulmonary disease have, until recently, all targeted downstream manifestations rather than the root cause of the disease. A step-change in our approach has been achieved in the last few years, with novel small-molecule CFTR modulating drugs entering the clinic.

AREAS COVERED

In this article, we will discuss the field of drug development for CF lung disease. The case will be made for the potential benefits of basic defect-targeted strategies, which will be described in detail. Novel therapies directed at the downstream pulmonary manifestations of CF - infection, inflammation, and mucus impaction - will be reviewed. Finally, we will speculate on future directions and challenges.

EXPERT OPINION

CF drug development is in an exciting phase, catalysed by the impressive results seen in patients with ivacaftor-responsive CFTR mutations. The research field is active with trials of novel therapies targeting the basic defect, alongside drugs targeting downstream effects. In order to detect potentially small improvements due to novel therapies, especially in the context of treating young patients with early disease, sensitive outcome measures and the coordinated efforts of collaborative research networks are crucial.

Safety and efficacy of prolonged levofloxacin inhalation solution (APT-1026) treatment for cystic fibrosis and chronic Pseudomonas aeruginosa airway infection

BACKGROUND

Levofloxacin inhalation solution (LIS) is the first aerosolized fluoroquinolone licensed for treatment of patients with cystic fibrosis (CF) and chronic Pseudomonas aeruginosa lung infection. This study evaluated the safety and efficacy of extended LIS treatment.

METHODS

Patients completing a multinational, randomized study comparing LIS and tobramycin inhalation solution (TIS) were enrolled in an open-label extension in which all patients received three additional cycles of 28days of LIS 240mg twice daily followed by 28days off drug. Endpoints included mean relative change in percent predicted forced expiratory volume in 1s (FEV1), time to pulmonary exacerbation, and patient-reported quality of life.

RESULTS

Extended treatment with LIS in 88 patients was well tolerated with no new safety signals and evidence of positive effects on FEV1 and quality of life.

CONCLUSION

Patients receiving extended LIS treatment continued to show favorable efficacy with no additional safety concerns.

Inhaled antibiotics: the new era of personalized medicine?

PURPOSE OF REVIEW

Treatment options for individuals with cystic fibrosis (CF) have improved survival significantly over the past two decades. One important treatment modality is inhaled antibiotics to treat chronic infection of the airways. This review includes those antibiotics that are currently in use, those that are in clinical trials. It also includes review of nonantibiotic antimicrobials, a growing area of investigation in CF.

RECENT FINDINGS

There are currently three inhaled antibiotics that are approved for use in patients with cystic fibrosis: tobramycin, aztreonam, and colistimethate. Tobramycin and colistimethate now are available as solution and new dry powder formulations, which are helping the treatment burden which has increased in CF. New antibiotics are in trial, although recently two did not meet primary outcomes in large clinical trials. Of particular interest is the development of nonantibiotic antimicrobials, which may allow treatment of intrinsically antibiotic resistant organisms.

SUMMARY

Inhaled antibiotics remain an important treatment option in cystic fibrosis due to chronic airway infection as a hallmark of the disease. Although there are now multiple options for treatment, improvements in this treatment class are needed to treat intrinsically resistant organisms. New formulation of antibiotics and nonantibiotic antimicrobials are being evaluated to add to our armamentarium.