Single-dose pharmacokinetics and lung function of nebulized niclosamide ethanolamine in sheep.

PURPOSE: Niclosamide is approved as an oral anthelminthic, but its low oral bioavailability hinders its medical use requiring high drug exposure outside the gastrointestinal tract. An optimized solution of niclosamide for nebulization and intranasal administration using the ethanolamine salt has been developed and tested in a Phase 1 trial. In this study we investigate the pulmonary exposure of niclosamide following administration via intravenous injection, oral administration or nebulization. METHODS: We characterized the plasma and pulmonary pharmacokinetics of three ascending doses of nebulized niclosamide in sheep, compare it to intravenous niclosamide for compartmental PK modelling, and to the human equivalent approved 2 g oral dose to investigate in the pulmonary exposure of different niclosamide delivery routes. Following a single-dose administration to five sheep, niclosamide concentrations were determined in plasma and epithelial lining fluid (ELF). Non-compartmental and compartmental modeling was used to characterize pharmacokinetic profiles. Lung function tests were performed in all dose groups. RESULTS: Administration of all niclosamide doses were well tolerated with no adverse changes in lung function tests. Plasma pharmacokinetics of nebulized niclosamide behaved dose-linear and was described by a 3-compartmental model estimating an absolute bioavailability of 86%. ELF peak concentration and area under the curve was 578 times and 71 times higher with nebulization of niclosamide relative to administration of oral niclosamide. CONCLUSIONS: Single local pulmonary administration of niclosamide via nebulization was well tolerated in sheep and resulted in substantially higher peak ELF concentration compared to the human equivalent oral 2 g dose.

Inhaled pirfenidone solution (AP01) for IPF: a randomised, open-label, dose-response trial.

INTRODUCTION: Oral pirfenidone reduces lung function decline and mortality in patients with idiopathic pulmonary fibrosis (IPF). Systemic exposure can have significant side effects, including nausea, rash, photosensitivity, weight loss and fatigue. Reduced doses may be suboptimal in slowing disease progression. METHODS: This phase 1b, randomised, open-label, dose-response trial at 25 sites in six countries (Australian New Zealand Clinical Trials Registry (ANZCTR) registration number ACTRN12618001838202) assessed safety, tolerability and efficacy of inhaled pirfenidone (AP01) in IPF. Patients diagnosed within 5 years, with forced vital capacity (FVC) 40%-90% predicted, and intolerant, unwilling or ineligible for oral pirfenidone or nintedanib were randomly assigned 1:1 to nebulised AP01 50 mg once per day or 100 mg two times per day for up to 72 weeks. RESULTS: We present results for week 24, the primary endpoint and week 48 for comparability with published trials of antifibrotics. Week 72 data will be reported as a separate analysis pooled with the ongoing open-label extension study. Ninety-one patients (50 mg once per day: n=46, 100 mg two times per day: n=45) were enrolled from May 2019 to April 2020. The most common treatment-related adverse events (frequency, % of patients) were all mild or moderate and included cough (14, 15.4%), rash (11, 12.1%), nausea (8, 8.8%), throat irritation (5, 5.5%), fatigue (4, 4.4%) and taste disorder, dizziness and dyspnoea (three each, 3.3%). Changes in FVC % predicted over 24 and 48 weeks, respectively, were -2.5 (95% CI -5.3 to 0.4, -88 mL) and -4.9 (-7.5 to -2.3,-188 mL) in the 50 mg once per day and 0.6 (-2.2 to 3.4, 10 mL) and -0.4 (-3.2 to 2.3, -34 mL) in the 100 mg two times per day group. DISCUSSION: Side effects commonly associated with oral pirfenidone in other clinical trials were less frequent with AP01. Mean FVC % predicted remained stable in the 100 mg two times per day group. Further study of AP01 is warranted. TRIAL REGISTRATION NUMBER: ACTRN12618001838202 Australian New Zealand Clinical Trials Registry.

Inhalation: A means to explore and optimize nintedanib's pharmacokinetic/pharmacodynamic relationship.

Oral nintedanib is marketed for the treatment of idiopathic pulmonary fibrosis (IPF). While effective slowing fibrosis progression, as an oral medicine nintedanib is limited. To reduce side effects and maximize efficacy, nintedanib was reformulated as a solution for nebulization and inhaled administration. To predict effectiveness treating IPF, the nintedanib pharmacokinetic/pharmacodynamic relationship was dissected. Pharmacokinetic analysis indicated oral-delivered nintedanib plasma exposure and lung tissue partitioning were not dose-proportional and resulting lung levels were substantially higher than blood. Although initial-oral absorbed nintedanib efficiently partitioned into the lung, only a quickly eliminated fraction appeared available to epithelial lining fluid (ELF). Because IPF disease appears to initiate and progress near the epithelial surface, this observation suggests short duration nintedanib exposure (oral portion efficiently partitioned to ELF) is sufficient for IPF efficacy. To test this hypothesis, exposure duration required for nintedanib activity was explored. In vitro, IPF-cellular matrix (IPF-CM) increased primary normal human fibroblast (nHLF) aggregate size and reduced nHLF cell count. IPF-CM also increased nHLF ACTA2 and COL1A expression. Whether short duration (inhalation pharmacokinetic mimic) or continuous exposure (oral pharmacokinetic mimic), nintedanib (1-100 nM) reversed these effects. In vivo, intubated silica produced a strong pulmonary fibrotic response. Once-daily (QD) 0.021, 0.21 and 2.1 mg/kg intranasal (IN; short duration inhaled exposure) and twice-daily (BID) 30 mg/kg oral (PO; long duration oral exposure) showed that at equivalent-delivered lung exposure, QD short duration inhaled nintedanib (0.21 mg/kg IN vs. 30 mg/kg PO) exhibited equivalent-to-superior activity as BID oral (reduced silica-induced elastance, alpha-smooth muscle actin, interleukin-1 beta (IL-1ß) and soluble collagen). Comparatively, the increased inhaled lung dose (2.1 mg/kg IN vs. 30 mg/kg PO) exhibited increased effect by further reducing silica-induced elastance, IL-1ß and soluble collagen. Neither oral nor inhaled nintedanib reduced silica-induced parenchymal collagen. Both QD inhaled and BID oral nintedanib reduced silica-induced bronchoalveolar lavage fluid macrophage and neutrophil counts with oral achieving significance. In summary, pharmacokinetic elements important for nintedanib activity can be delivered using infrequent, small inhaled doses to achieve oral equivalent-to-superior pulmonary activity.

A Randomized, Double-Blinded, Placebo-Controlled, Dose-Escalation Phase 1 Study of Aerosolized Pirfenidone Delivered via the PARI Investigational eFlow Nebulizer in Volunteers and Patients with Idiopathic Pulmonary Fibrosis.

Background: This clinical trial evaluated the pharmacokinetics and safety/tolerability of inhaled pirfenidone solution in volunteers and patients with idiopathic pulmonary fibrosis (IPF). Methods: Forty-four adults in six cohorts consented to receive single doses of a 12.5 mg/mL pirfenidone solution or placebo to assess tolerability and pharmacokinetics. Cohorts 1, 2, and 3 (normal healthy volunteers [NHV]) (n = 6 active; n = 2 placebo in each cohort) received 25, 50, and 100 mg pirfenidone, respectively. Cohort 4 (NHV) (n = 6 all active) received 100 mg of pirfenidone and underwent bronchoalveolar lavage (BAL) to measure epithelial lining fluid (ELF) pirfenidone concentrations. Cohort 5 (prior or current smokers with greater than 20 pack-year use) (n = 6 active; n = 2 placebo) and Cohort 6 (IPF patients) (n = 6 all active) received 100 mg of pirfenidone. All treatments were administered with an Investigational eFlow® Nebulizer System (PARI Pharma GmbH). Serial measures of urine and plasma pirfenidone were collected during the 24-hour postdose in all subjects. Results: Administration time ranged from 1.4 to 2 min/mL. No clinically relevant adverse effects on respiratory rate, spirometry, or oxygenation were observed. Drug-related adverse events were predominantly cough, n = 8/44 (one in IPF cohort), all mild, transient, and not dose limiting. Mean plasma pirfenidone Cmax levels in the 25, 50, 100 mg NHV, 100 mg smoker, and IPF cohorts were 202, 292, 802, 1370, 1016, and 1026 ng/mL, respectively. BAL cohort estimated ELF Cmax was 135.9 ± 54.5 µg/mL. In the BAL and IPF cohorts, 24-hour urine excretion of pirfenidone and metabolites data suggests similar alveolar deposition. Conclusions: Aerosol pirfenidone was well tolerated in normal volunteers, smokers, and IPF patients. High ELF concentrations were achieved in NHV with a 100 mg nebulizer dose. The 100 mg nebulizer dose averaged a 15-fold lower systemic pirfenidone exposure than reported with oral administration of the licensed oral dose.

Aerosol Pirfenidone Pharmacokinetics after Inhaled Delivery in Sheep: a Viable Approach to Treating Idiopathic Pulmonary Fibrosis.

PURPOSE: Inhaled delivery of pirfenidone to the lungs of patients with idiopathic pulmonary fibrosis holds promise to eliminate oral-observed side effects while enhancing efficacy. This study aimed to comprehensively describe the pulmonary pharmacokinetics of inhaled aerosol pirfenidone in healthy adult sheep. METHODS: Pirfenidone concentrations were evaluated in plasma, lung-derived lymph and epithelial lining fluid (ELF) with data subjected to non-compartmental pharmacokinetic analysis. RESULTS: Compartmental pharmacokinetic evaluation indicated that a 49 mg lung-deposited dose delivered an ELF Cmax of 62 ± 23 mg/L, and plasma Cmax of 3.1 ± 1.7 mg/L. Further analysis revealed that plasma pirfenidone reached Tmax faster and at higher concentrations than in lymph. These results suggested inhaled pirfenidone was cleared from the alveolar interstitium via blood faster than the drug could equilibrate between the lung interstitial fluid and lung lymphatics. However, the data also suggested that a 'reservoir' of pirfenidone feeds into lung lymph at later time points (after it has largely been cleared from plasma), prolonging lung lymphatic exposure. CONCLUSIONS: This study indicates inhaled pirfenidone efficiently deposits in ELF and is cleared from the lungs by initial absorption into plasma, followed by later equilibrium with lung interstitial and lymph fluid.

Nebulized Amikacin and Fosfomycin for Severe Pseudomonas aeruginosa Pneumonia: An Experimental Study.

OBJECTIVES: Latest trials failed to confirm merits of nebulized amikacin for critically ill patients with nosocomial pneumonia. We studied various nebulized and IV antibiotic regimens in a porcine model of severe Pseudomonas aeruginosa pneumonia, resistant to amikacin, fosfomycin, and susceptible to meropenem. DESIGN: Prospective randomized animal study. SETTING: Animal Research, University of Barcelona, Spain. SUBJECTS: Thirty female pigs. INTERVENTIONS: The animals were randomized to receive nebulized saline solution (CONTROL); nebulized amikacin every 6 hours; nebulized fosfomycin every 6 hours; IV meropenem alone every 8 hours; nebulized amikacin and fosfomycin every 6 hours; amikacin and fosfomycin every 6 hours, with IV meropenem every 8 hours. Nebulization was performed through a vibrating mesh nebulizer. The primary outcome was lung tissue bacterial concentration. Secondary outcomes were tracheal secretions P. aeruginosa concentration, clinical variables, lung histology, and development of meropenem resistance. MEASUREMENTS AND MAIN RESULTS: We included five animals into each group. Lung P. aeruginosa burden varied among groups (p < 0.001). In particular, IV meropenem and amikacin and fosfomycin + IV meropenem groups presented lower P. aeruginosa concentrations versus amikacin and fosfomycin, amikacin, CONTROL, and fosfomycin groups (p < 0.05), without significant difference between these two groups undergoing IV meropenem treatment. The sole use of nebulized antibiotics resulted in dense P. aeruginosa accumulation at the edges of the interlobular septa. Amikacin, amikacin and fosfomycin, and amikacin and fosfomycin + IV meropenem effectively reduced P. aeruginosa in tracheal secretions (p < 0.001). Pathognomonic clinical variables of respiratory infection did not differ among groups. Resistance to meropenem increased in IV meropenem group versus amikacin and fosfomycin + meropenem (p = 0.004). CONCLUSIONS: Our findings corroborate that amikacin and fosfomycin alone efficiently reduced P. aeruginosa in tracheal secretions, with negligible effects in pulmonary tissue. Combination of amikacin and fosfomycin with IV meropenem does not increase antipseudomonal pulmonary tissue activity, but it does reduce development of meropenem-resistant P. aeruginosa, in comparison with the sole use of IV meropenem. Our findings imply potential merits for preemptive use of nebulized antibiotics in order to reduce resistance to IV meropenem.

Pharmacodynamics of Aerosolized Fosfomycin and Amikacin against Resistant Clinical Isolates of Pseudomonas aeruginosa and Klebsiella pneumoniae in a Hollow-Fiber Infection Model: Experimental Basis for Combination Therapy.

There has been a resurgence of interest in aerosolization of antibiotics for treatment of patients with severe pneumonia caused by multidrug-resistant pathogens. A combination formulation of amikacin-fosfomycin is currently undergoing clinical testing although the exposure-response relationships of these drugs have not been fully characterized. The aim of this study was to describe the individual and combined antibacterial effects of simulated epithelial lining fluid exposures of aerosolized amikacin and fosfomycin against resistant clinical isolates of Pseudomonas aeruginosa (MICs of 16 mg/liter and 64 mg/liter) and Klebsiella pneumoniae (MICs of 2 mg/liter and 64 mg/liter) using a dynamic hollow-fiber infection model over 7 days. Targeted peak concentrations of 300 mg/liter amikacin and/or 1,200 mg/liter fosfomycin as a 12-hourly dosing regimens were used. Quantitative cultures were performed to describe changes in concentrations of the total and resistant bacterial populations. The targeted starting inoculum was 108 CFU/ml for both strains. We observed that neither amikacin nor fosfomycin monotherapy was bactericidal against P. aeruginosa while both were associated with rapid amplification of resistant P. aeruginosa strains (about 108 to 109 CFU/ml within 24 to 48 h). For K. pneumoniae, amikacin but not fosfomycin was bactericidal. When both drugs were combined, a rapid killing was observed for P. aeruginosa and K. pneumoniae (6-log kill within 24 h). Furthermore, the combination of amikacin and fosfomycin effectively suppressed growth of resistant strains of P. aeruginosa and K. pneumoniae In conclusion, the combination of amikacin and fosfomycin was effective at maximizing bacterial killing and suppressing emergence of resistance against these clinical isolates.

A Randomized Trial of the Amikacin Fosfomycin Inhalation System for the Adjunctive Therapy of Gram-Negative Ventilator-Associated Pneumonia: IASIS Trial.

BACKGROUND: Clinical failures in ventilator-associated pneumonia (VAP) caused by gram-negative bacteria are common and associated with substantial morbidity, mortality, and resource utilization. METHODS: We assessed the safety and efficacy of the amikacin fosfomycin inhalation system (AFIS) for the treatment of gram-negative bacterial VAP in a randomized double-blind, placebo-controlled, parallel group, phase 2 study between May 2013 and March 2016. We compared standard of care in each arm plus 300 mg amikacin/120 mg fosfomycin or placebo (saline), delivered by aerosol twice daily for 10 days (or to extubation if < 10 days) via the investigational eFlow Inline System (PARI GmbH). The primary efficacy end point was change from baseline in the Clinical Pulmonary Infection Score (CPIS) during the randomized course of AFIS/placebo, using the subset of patients with microbiologically proven baseline infections with gram-negative bacteria. RESULTS: There were 143 patients randomized: 71 to the AFIS group, and 72 to the placebo group. Comparison of CPIS change from baseline between treatment groups was not different (P = .70). The secondary hierarchical end point of no mortality and clinical cure at day 14 or earlier was also not significant (P = .68) nor was the hierarchical end point of no mortality and ventilator-free days (P = .06). The number of deaths in the AFIS group was 17 (24%) and 12 (17%) in the placebo group (P = .32). The AFIS group had significantly fewer positive tracheal cultures on days 3 and 7 than placebo. CONCLUSIONS: In this trial of adjunctive aerosol therapy compared with standard of care IV antibiotics in patients with gram-negative VAP, the AFIS was ineffective in improving clinical outcomes despite reducing bacterial burden. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01969799; URL: www.clinicaltrials.gov.

Mucin Binding Reduces Colistin Antimicrobial Activity.

Colistin has found increasing use in treating drug-resistant bacterial lung infections, but potential interactions with pulmonary biomolecules have not been investigated. We postulated that colistin, like aminoglycoside antibiotics, may bind to secretory mucin in sputum or epithelial mucin that lines airways, reducing free drug levels. To test this hypothesis, we measured binding of colistin and other antibiotics to porcine mucin, a family of densely glycosylated proteins used as a surrogate for human sputum and airway mucin. Antibiotics were incubated in dialysis tubing with or without mucin, and concentrations of unbound antibiotics able to penetrate the dialysis tubing were measured over time using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The percentage of antibiotic measured in the dialysate after 4 h in the presence of mucin, relative to the amount without mucin, was 15% for colistin, 16% for polymyxin B, 19% for tobramycin, 52% for ciprofloxacin, and 78% for daptomycin. Antibiotics with the strongest mucin binding had an overall polybasic positive charge, whereas those with comparatively little binding were less basic. When comparing MICs measured with or without added mucin, colistin and polymyxin B showed >100-fold increases in MICs for multiple Gram-negative bacteria. Preclinical evaluation of mucin binding should become a standard procedure when considering the potential pulmonary use of new or existing antibiotics, particularly those with a polybasic overall charge. In the airways, mucin binding may reduce the antibacterial efficacy of inhaled or intravenously administered colistin, and the presence of sub-MIC effective antibiotic concentrations could result in the development of antibiotic resistance.

Quality of Life Questionnaire-Bronchiectasis: final psychometric analyses and determination of minimal important difference scores.

BACKGROUND: The Quality of Life-Bronchiectasis (QOL-B), a self-administered, patient-reported outcome measure assessing symptoms, functioning and health-related quality of life for patients with non-cystic fibrosis (CF) bronchiectasis, contains 37 items on 8 scales (Respiratory Symptoms, Physical, Role, Emotional and Social Functioning, Vitality, Health Perceptions and Treatment Burden). METHODS: Psychometric analyses of QOL-B V.3.0 used data from two double-blind, multicentre, randomised, placebo-controlled, phase III trials of aztreonam for inhalation solution (AZLI) in 542 patients with non-CF bronchiectasis and Gram-negative endobronchial infection. RESULTS: Excellent internal consistency (Cronbach's α ≥0.70) and 2-week test-retest reliability (intraclass correlation coefficients ≥0.72) were demonstrated for each scale. Convergent validity with 6 min walk test was observed for Physical and Role Functioning scores. No floor or ceiling effects (baseline scores of 0 or 100) were found for the Respiratory Symptoms scale (primary endpoint of trials). Baseline Respiratory Symptoms scores discriminated between patients based on baseline FEV1% predicted in only one trial. The minimal important difference score for the Respiratory Symptoms scale was 8.0 points. AZLI did not show efficacy in the two phase III trials. QOL-B responsivity to treatment was assessed by examining changes from baseline QOL-B scores at study visits at which protocol-defined pulmonary exacerbations were reported. Mean Respiratory Symptoms scores decreased 14.0 and 14.2 points from baseline for placebo-treated and AZLI-treated patients with exacerbations, indicating that worsening respiratory symptoms were reflected in clinically meaningful changes in QOL-B scores. CONCLUSIONS: Previously established content validity, reliability and responsivity of the QOL-B are confirmed by this final validation study. The QOL-B is available for use in clinical trials and routine clinical practice.

Aztreonam for inhalation solution in patients with non-cystic fibrosis bronchiectasis (AIR-BX1 and AIR-BX2): two randomised double-blind, placebo-controlled phase 3 trials.

BACKGROUND: The clinical benefit of inhaled antibiotics in non-cystic fibrosis bronchiectasis has not been established in randomised controlled trials. We aimed to assess safety and efficacy of aztreonam for inhalation solution (AZLI) in patients with non-cystic fibrosis bronchiectasis and Gram-negative bacterial colonisation. METHODS: AIR-BX1 and AIR-BX2 were two double-blind, multicentre, randomised, placebo-controlled phase 3 trials, which included patients aged 18 years or older who had bronchiectasis and history of positive sputum or bronchoscopic culture for target Gram-negative organisms. Patients were randomly assigned to receive either AZLI or placebo (1:1). Randomisation was done without stratification and the code was generated by a Gilead designee. In both studies, two 4-week courses of AZLI 75 mg or placebo (three-times daily; eFlow nebulizer) were each followed by a 4-week off-treatment period. Primary endpoint was change from baseline Quality of Life-Bronchiectasis Respiratory Symptoms scores (QOL-B-RSS) at 4 weeks. These trials are registered with ClinicalTrials.gov, numbers are NCT01313624 for AIR-BX1 and NCT01314716 for AIR-BX2. FINDINGS: We recruited participants from 47 ambulatory clinics for AIR-BX1 and 65 ambulatory clinics for AIR-BX2; studies were done between April 25, 2011, and July 1, 2013. In AIR-BX1, of the 348 patients screened, 134 were randomly assigned to receive AZLI and 132 to receive placebo. In AIR-BX2, of the 404 patients screened, 136 were randomly assigned to receive AZLI and 138 to receive placebo. The difference between AZLI and placebo for adjusted mean change from baseline QOL-B-RSS was not significant at 4 weeks (0.8 [95% CI -3.1 to 4.7], p=0.68) in AIR-BX1, but was significant (4.6 [1.1 to 8.2], p=0.011) in AIR-BX2. The 4.6 point difference in QOL-B-RSS after 4 weeks in AIR-BX2 was not deemed clinically significant. In both studies, treatment-related adverse events were more common in the AZLI group than in the placebo group, as were discontinuations from adverse events. The most commonly reported treatment-emergent adverse events were dyspnea, cough, and increased sputum. Each was more common for AZLI-treated than for placebo-treated patients, but the incidences were more balanced in AIR-BX2. INTERPRETATION: AZLI treatment did not provide significant clinical benefit in non-cystic fibrosis bronchiectasis, as measured by QOL-B-RSS, suggesting a continued need for placebo-controlled studies to establish the clinical benefit of inhaled antibiotics in patients with this disorder. FUNDING: Gilead Sciences.

Potentiation effects of amikacin and fosfomycin against selected amikacin-nonsusceptible Gram-negative respiratory tract pathogens.

The amikacin-fosfomycin inhalation system (AFIS) is a combination of 2 antibiotics and an in-line nebulizer delivery system that is being developed for adjunctive treatment of pneumonia caused by Gram-negative organisms in patients on mechanical ventilation. AFIS consists of a combination of amikacin and fosfomycin solutions at a 5:2 ratio (amikacin, 3 ml at 100 mg/ml; fosfomycin, 3 ml at 40 mg/ml) and the PARI Investigational eFlow Inline System. In this antibiotic potentiation study, the antimicrobial activities of amikacin and fosfomycin, alone and in a 5:2 combination, were assessed against 62 Gram-negative pathogens from a worldwide antimicrobial surveillance collection (SENTRY). The amikacin MICs for 62 isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae were ≥32 µg/ml (intermediate or resistant according to the Clinical and Laboratory Standards Institute [CLSI]; resistant according to the European Committee on Antimicrobial Susceptibility Testing [EUCAST]). Each isolate was tested against amikacin (0.25 to 1,024 µg/ml), fosfomycin (0.1 to 409.6 µg/ml), and amikacin-fosfomycin (at a 5:2 ratio) using CLSI reference agar dilution methods. The median MIC values for amikacin and fosfomycin against the 62 isolates each decreased 2-fold with the amikacin-fosfomycin (5:2) combination from that with either antibiotic alone. Interactions between amikacin and fosfomycin differed by isolate and ranged from no detectable interaction to high potentiation. The amikacin-fosfomycin (5:2) combination reduced the amikacin concentration required to inhibit all 62 isolates from >1,024 to ≤ 256 µg/ml and reduced the required fosfomycin concentration from 204.8 to 102.4 µg/ml. These results support continued development of the amikacin-fosfomycin combination for aerosolized administration, where high drug levels can be achieved.

Amikacin-fosfomycin at a five-to-two ratio: characterization of mutation rates in microbial strains causing ventilator-associated pneumonia and interactions with commonly used antibiotics.

The amikacin-fosfomycin inhalation system (AFIS), a combination of antibiotics administered with an in-line nebulizer delivery system, is being developed for adjunctive treatment of ventilator-associated pneumonia (VAP). The in vitro characterization of amikacin-fosfomycin (at a 5:2 ratio) described here included determining resistance selection rates for pathogens that are representative of those commonly associated with VAP (including multidrug-resistant strains) and evaluating interactions with antibiotics commonly used intravenously to treat VAP. Spontaneous resistance to amikacin-fosfomycin (5:2) was not observed for most strains tested (n, 10/14). Four strains had spontaneously resistant colonies (frequencies, 4.25 × 10(-8) to 3.47 × 10(-10)), for which amikacin-fosfomycin (5:2) MICs were 2- to 8-fold higher than those for the original strains. After 7 days of serial passage, resistance (>4-fold increase over the baseline MIC) occurred in fewer strains (n, 4/14) passaged in the presence of amikacin-fosfomycin (5:2) than with either amikacin (n, 7/14) or fosfomycin (n, 12/14) alone. Interactions between amikacin-fosfomycin (5:2) and 10 comparator antibiotics in checkerboard testing against 30 different Gram-positive or Gram-negative bacterial strains were synergistic (fractional inhibitory concentration [FIC] index, ≤ 0.5) for 6.7% (n, 10/150) of combinations tested. No antagonism was observed. Synergy was confirmed by time-kill methodology for amikacin-fosfomycin (5:2) plus cefepime (against Escherichia coli), aztreonam (against Pseudomonas aeruginosa), daptomycin (against Enterococcus faecalis), and azithromycin (against Staphylococcus aureus). Amikacin-fosfomycin (5:2) was bactericidal at 4-fold the MIC for 7 strains tested. The reduced incidence of development of resistance to amikacin-fosfomycin (5:2) compared with that for amikacin or fosfomycin alone, and the lack of negative interactions with commonly used intravenous antibiotics, further supports the development of AFIS for the treatment of VAP.

Diagnosis of idiopathic pulmonary fibrosis with high-resolution CT in patients with little or no radiological evidence of honeycombing: secondary analysis of a randomised, controlled trial.

BACKGROUND: Present guidelines for the diagnosis of idiopathic pulmonary fibrosis require histological confirmation of surgical lung biopsy samples when high-resolution CT images are not definitive for usual interstitial pneumonia. We aimed to assess the predictive value of high-resolution CT in a cohort of patients with suspected idiopathic pulmonary fibrosis from a previous randomised trial. METHODS: ARTEMIS-IPF was a randomised, double-blind, placebo-controlled, multicentre, phase 3 trial of ambrisentan for adults aged 40-80 years with well-defined idiopathic pulmonary fibrosis and 5% or less honeycombing on high-resolution CT. In December, 2010, an interim analysis showed lack of efficacy and the trial was stopped. In the present follow-on analysis, we assessed patients who were screened for ARTEMIS-IPF who underwent high-resolution CT as part of screening and surgical lung biopsy as part of standard clinical care. A radiologist and a pathologist from a central panel independently assessed anonymised CT scans and biopsy samples. We calculated the positive and negative predictive value of high-resolution CT (classified as usual interstitial pneumonia, possible usual interstitial pneumonia, and inconsistent with usual interstitial pneumonia) for confirmation of histological patterns of usual interstitial pneumonia. This study is registered with ClinicalTrials.gov, number NCT00768300. FINDINGS: 315 (29%) of 1087 consecutively screened patients in ARTEMIS-IPF had both high-resolution CT and surgical lung biopsy samples. 108 of 111 patients who met high-resolution CT criteria for usual interstitial pneumonia had histologically confirmed usual interstitial pneumonia (positive predictive value 97·3%, 95% CI 92·3-99·4), as did 79 of 84 patients who met high-resolution CT criteria for possible usual interstitial pneumonia (94·0%, 86·7-98·0). 22 of 120 patients had an inconsistent high-resolution CT pattern for usual interstitial pneumonia that was histologically confirmed as not or possible usual interstitial pneumonia (negative predictive value 18·3%, 95% CI 11·9-26·4). INTERPRETATION: In the appropriate clinical setting, for patients with possible usual interstitial pneumonia pattern on high resolution CT, surgical lung biopsy sampling might not be necessary to reach a diagnosis of idiopathic pulmonary fibrosis if high-resolution CT scans are assessed by experts at regional sites familiar with patterns of usual interstitial pneumonia and management of idiopathic interstitial pneumonia. FUNDING: Gilead Sciences.

A preliminary quality of life questionnaire-bronchiectasis: a patient-reported outcome measure for bronchiectasis.

BACKGROUND: The Quality of Life Questionnaire-Bronchiectasis (QOL-B) is the first disease-specific, patient-reported outcome measure for patients with bronchiectasis. Content validity, cognitive testing, responsivity to open-label treatment, and psychometric analyses are presented. METHODS: Reviews of literature, existing measures, and physician input were used to generate the initial QOL-B. Modifications following preliminary cognitive testing (N = 35 patients with bronchiectasis) generated version (V) 1.0. An open-ended patient interview study (N = 28) provided additional information and was content analyzed to derive saturation matrices, which summarized all disease-related topics mentioned by each participant. This resulted in QOL-B V2.0. Psychometric analyses were carried out using results from an open-label phase 2 trial, in which 89 patients were enrolled and treated with aztreonam for inhalation solution. Responsivity to open-label treatment was observed. Additional analyses generated QOL-B V3.0, with 37 items on eight scales: respiratory symptoms; physical, role, emotional, and social functioning; vitality; health perceptions; and treatment burden. For each scale, scores are standardized on a 0-to-100-point scale; higher scores indicate better health-related quality of life. No total score is calculated. A final cognitive testing study (N = 40) resulted in a minor change to one social functioning scale item (QOL-B V3.1). RESULTS: Content validity, cognitive testing, responsivity to open-label treatment, and initial psychometric analyses supported QOL-B items and structure. CONCLUSIONS: This interim QOL-B is a promising tool for evaluating the efficacy of new therapies for patients with bronchiectasis and for measuring symptoms, functioning, and quality of life in these patients on a routine basis. A final psychometric validation study is needed and is forthcoming. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00805025; URL: www.clinicaltrials.gov.

A randomized double-blind placebo-controlled dose-escalation phase 1 study of aerosolized amikacin and fosfomycin delivered via the PARI investigational eFlow® inline nebulizer system in mechanically ventilated patients.

BACKGROUND: This clinical trial evaluated the pharmacokinetics and safety/tolerability of amikacin/fosfomycin solution using a vibrating plate nebulizer, in mechanically ventilated patients with ventilator-associated tracheobronchitis (VAT) or ventilator-associated pneumonia (VAP). METHODS: Nine adult patients were consented to receive three escalating doses of a combination of 50 mg/mL amikacin and 20 mg/mL fosfomycin; doses were separated by 24±2 hr. On day 3, patients received two blinded, randomized treatments (amikacin/fosfomycin and volume-matched placebo), separated by 2 hr. All treatments were administered with a single-patient, multitreatment nebulizer (Investigational eFlow(®) Inline Nebulizer System; PARI Pharma GmbH, positioned in the inspiratory limb tubing between the ventilator and the patient. The nebulizer remained in-line until all treatments had been delivered. Concentrations of amikacin and fosfomycin were measured in tracheal aspirate and plasma samples obtained during the 24 hr after each dose. RESULTS: Fifteen minutes after dosing with the 300/120 mg amikacin/fosfomycin combination, tracheal aspirate amikacin concentrations±SD were 12,390±3,986 µg/g, and fosfomycin concentrations were 6,174±2,548 µg/g (n=6). Airway clearance was rapid. Plasma concentrations were subtherapeutic; the highest observed amikacin plasma concentration was 1.4 µg/mL, and the highest observed fosfomycin plasma concentration was 0.8 µg/mL. Administration time was approximately 2 min/mL. No adverse effects on respiratory rate, peak airway pressures, or oxygenation were observed during or following drug or placebo administration. CONCLUSIONS: High tracheal aspirate concentrations of amikacin and fosfomycin were achieved in mechanically ventilated patients with VAT or VAP after aerosolized administration with an inline nebulizer system. Airway clearance was rapid. No adverse respiratory effects were noted during or following drug administration.

Acute hyperkalemia associated with inhalation of a potent ENaC antagonist: Phase 1 trial of GS-9411.

BACKGROUND: Inhaled epithelial sodium channel (ENaC) blockers are designed to increase airway surface liquid volume, thereby benefiting cystic fibrosis patients. This study evaluated the safety, tolerability, and pharmacokinetics of multiple doses of ENaC blocker GS-9411, in healthy participants. METHODS: This randomized, double-blind, placebo-controlled, parallel-group, residential, Phase 1 study evaluated inhaled GS-9411 (2.4, 4.8, and 9.6 mg) or placebo, dosed twice daily for 14 days. RESULTS AND CONCLUSIONS: GS-9411 was well tolerated; 86.1% of treated participants completed dosing (n=31/36). Cough and dizziness (27.8% participants each; most of mild severity) were the most commonly reported adverse events and occurred in both placebo and GS-9411 treatment groups. Arrhythmias were not observed for GS-9411-treated participants, and electrocardiographic changes were not considered clinically significant. Serum potassium levels exceeded the upper limit of normal (>5 mmol/L), 4 hr after the morning dose in GS-9411 (n=16/24) and placebo (n=4/12) treatment groups (38 incidences total). Retesting revealed levels had returned to normal within 2-3 hr. In urine electrolyte analyses, obtained 0-6 hr after the Day 1 morning dose, mean sodium/potassium ratios significantly increased from values 0-6 hr before dosing. Increased urine sodium/potassium ratios corresponded with high urine concentrations of active GS-9411 metabolites, which inhibited sodium reabsorption in the kidney, leading to the observed transient hyperkalemia in these participants. Inhaled GS-9411 was well tolerated except for the emergence of transient clinically significant hyperkalemia; this finding resulted in termination of further clinical development of this drug and will necessitate development of a new generation of ENaC blockers, which provide a sustained improvement in mucociliary clearance, while reducing renal exposure to ENaC blockade. Transient increases in mean urine sodium/potassium ratios appeared to be the first signal of electrolyte imbalances resulting from drug-induced block of ENaC in the kidney. The results of this study strongly suggest that clinical trials of novel ENaC blockers will require intensive measurement of plasma and urine electrolyte levels.

Aerosolized antibiotics: do they add to the treatment of pneumonia?

PURPOSE OF REVIEW: The increasing rate of ventilator-associated pneumonia (VAP) caused by multidrug-resistant pathogens warrants the development of new treatment strategies. Carefully engineered delivery systems are undergoing evaluation to test the hypothesis that aerosolized administration of antibiotics will provide high local concentrations and fast clearance, which in turn may improve efficacy and decrease the risk of microbial resistance. RECENT FINDINGS: Recent studies indicate that aerosolized delivery systems for specially formulated antibiotics yield high local concentrations with rapid clearance and low systemic exposure. Preliminary clinical studies reveal that aerosolized delivery of antibiotics is well tolerated and active, when combined with intravenous antibiotics. No single aerosolized antibiotic is likely to provide broad-spectrum activity against both Gram-negative and Gram-positive bacteria. SUMMARY: Large multicenter trials are needed to determine whether preliminary findings will translate to improved clinical activity and decreased microbial resistance in VAP patients, and to optimize the use of aerosolized antibiotics.