CXCR2 antagonist for patients with chronic obstructive pulmonary disease with chronic mucus hypersecretion: a phase 2b trial.

BACKGROUND: Oral CXC chemokine receptor 2 (CXCR2) antagonists have been shown to inhibit neutrophil migration and activation in the lung in preclinical and human models of neutrophilic airway inflammation. A previous study with danirixin, a reversible CXCR2 antagonist, demonstrated a trend for improved respiratory symptoms and health status in patients with COPD. METHODS: This 26-week, randomised, double-blind, placebo-controlled phase IIb study enrolled symptomatic patients with mild-to-moderate COPD at risk for exacerbations. Patients received danirixin 5, 10, 25, 35 or 50 mg twice daily or placebo in addition to standard of care. Primary end-points were the dose response of danirixin compared with placebo on the incidence and severity of respiratory symptoms (Evaluating Respiratory Symptoms in COPD [E-RS:COPD] scores) and safety. Secondary end-points included the incidence of moderate-severe exacerbations, health status (COPD Assessment test, CAT) and health-related quality of life HRQoL (St. George Respiratory Questionnaire-COPD, SGRQ-C). RESULTS: A total of 614 participants were randomized to treatment. There were no improvements in E-RS:COPD, CAT or SGRQ-C scores in participants treated with any dose of danirixin compared to placebo; a larger than expected placebo effect was observed. There was an increased incidence of exacerbation in the danirixin-treated groups and an increased number of pneumonias in participants treated with danirixin 50 mg. CONCLUSIONS: The robust placebo and study effects prohibited any conclusions on the efficacy of danirixin. However, the absence of a clear efficacy benefit and the observed increase in exacerbations in danirixin-treated groups suggests an unfavorable benefit-risk profile in patients with COPD. TRIAL REGISTRATION: This study was registered with clinicaltrials.gov, NCT03034967.

Investigating the effect of TRPV4 inhibition on pulmonary-vascular barrier permeability following segmental endotoxin challenge.

BACKGROUND: Acute Respiratory Distress Syndrome (ARDS) is associated with increased pulmonary-vascular permeability. In the lung, transient receptor potential vanilloid 4 (TRPV4), a Ca2+-permeable cation channel, is a regulator of endothelial permeability and pulmonary edema. We performed a Phase I, placebo-controlled, double-blind, randomized, parallel group, proof-of-mechanism study to investigate the effects of TRPV4 channel blocker, GSK2798745, on pulmonary-vascular barrier permeability using a model of lipopolysaccharide (LPS)-induced lung inflammation. METHODS: Healthy participants were randomized 1:1 to receive 2 single doses of GSK2798745 or placebo, 12 h apart. Two hours after the first dose, participants underwent bronchoscopy and segmental LPS instillation. Total protein concentration and neutrophil counts were measured in bronchoalveolar lavage (BAL) samples collected before and 24 h after LPS challenge, as markers of barrier permeability and inflammation, respectively. The primary endpoint was baseline adjusted total protein concentration in BAL at 24 h after LPS challenge. A Bayesian framework was used to estimate the posterior probability of any percentage reduction (GSK2798745 relative to placebo). Safety endpoints included the incidence of adverse events (AEs), vital signs, 12-lead electrocardiogram, clinical laboratory and haematological evaluations, and spirometry. RESULTS: Forty-seven participants were dosed and 45 completed the study (22 on GSK2798745 and 23 on placebo). Overall, GSK2798745 was well tolerated. Small reductions in mean baseline adjusted BAL total protein (~9%) and neutrophils (~7%) in the LPS-challenged segment were observed in the GSK2798745 group compared with the placebo group; however, the reductions did not meet pre-specified success criteria of at least a 95% posterior probability that the percentage reduction in the mean 24-h post LPS BAL total protein level (GSK2798745 relative to placebo) exceeded zero. Median plasma concentrations of GSK2798745 were predicted to inhibit TRPV4 on lung vascular endothelial cells by ~70-85% during the 24 h after LPS challenge; median urea-corrected BAL concentrations of GSK2798745 were 3.0- to 8.7-fold higher than those in plasma. CONCLUSIONS: GSK2798745 did not affect segmental LPS-induced elevation of BAL total protein or neutrophils, despite blood and lung exposures that were predicted to be efficacious. CLINICALTRIALS. GOV IDENTIFIER: NCT03511105.

A nebulised antitumour necrosis factor receptor-1 domain antibody in patients at risk of postoperative lung injury: A randomised, placebo-controlled pilot study.

BACKGROUND: Tumour necrosis factor receptor 1 (TNFR1) signalling mediates the cell death and inflammatory effects of TNF-α. OBJECTIVE: The current clinical trial investigated the effects of a nebulised TNFR1 antagonist (GSK2862277) on signs of lung injury in patients undergoing oesophagectomy. DESIGN: Randomised double-blind (sponsor unblind), placebo-controlled, parallel group study. SETTING: Eight secondary care centres, the United Kingdom between April 2015 and June 2017. PATIENTS: Thirty-three patients undergoing elective transthoracic oesophagectomy. INTERVENTIONS: Patients randomly received a single nebulised dose (26 mg) of GSK2862277 (n = 17) or placebo (n = 16), given 1 to 5 h before surgery; 14 and 16, respectively competed the study. MAIN OUTCOME MEASUREMENTS: Physiological and biochemical markers of lung injury, pharmacokinetic and safety endpoints were measured. The primary endpoint was the change from baseline in pulmonary vascular permeability index (PVPI) at completion of surgery, measured using single-indicator transpulmonary thermodilution. Adjusted point estimates and 95% credible intervals (analogous to conventional confidence intervals) were constructed for each treatment using Bayesian statistical models. RESULTS: The mean change (with 95% credible intervals) from baseline in PVPI on completion of surgery was 0.00 (-0.23, 0.39) in the placebo and 0.00 (-0.24, 0.37) in the GSK2862277 treatment groups. There were no significant treatment-related differences in PaO2/FiO2 or Sequential Organ Failure Assessment score. Levels of free soluble TNFR1, Macrophage Inflammatory Protein-1 alpha and total protein were significantly reduced in the bronchoalveolar lavage fluid of patients treated with GSK2862277 (posterior probability of decrease with GSK2862277 vs. placebo:≥0.977; equivalent to P < 0.05). The frequency of adverse events and serious adverse events were distributed evenly across the two treatment arms. CONCLUSION: Pre-operative treatment with a single 26 mg inhaled dose of GSK2862277 did not result in significantly lower postoperative alveolar capillary leak or extra vascular lung water. Unexpectedly small increases in transpulmonary thermodilution-measured PVPI and extra vascular lung water index at completion of surgery suggest less postoperative lung injury than historically reported, which may have also compromised a clear assessment of efficacy in this trial. GSK2862277 was well tolerated, resulted in expected lung exposure and reduced biomarkers of lung permeability and inflammation. TRIAL REGISTRATION: clinicaltrials.gov: NCT02221037.

Plasma sTNFR1 and IL8 for prognostic enrichment in sepsis trials: a prospective cohort study.

BACKGROUND: Enrichment strategies improve therapeutic targeting and trial efficiency, but enrichment factors for sepsis trials are lacking. We determined whether concentrations of soluble tumor necrosis factor receptor-1 (sTNFR1), interleukin-8 (IL8), and angiopoietin-2 (Ang2) could identify sepsis patients at higher mortality risk and serve as prognostic enrichment factors. METHODS: In a multicenter prospective cohort study of 400 critically ill septic patients, we derived and validated thresholds for each marker and expressed prognostic enrichment using risk differences (RD) of 30-day mortality as predictive values. We then used decision curve analysis to simulate the prognostic enrichment of each marker and compare different prognostic enrichment strategies. MEASUREMENTS AND MAIN RESULTS: An admission sTNFR1 concentration > 8861 pg/ml identified patients with increased mortality in both the derivation (RD 21.6%) and validation (RD 17.8%) populations. Among immunocompetent patients, an IL8 concentration > 94 pg/ml identified patients with increased mortality in both the derivation (RD 17.7%) and validation (RD 27.0%) populations. An Ang2 level > 9761 pg/ml identified patients at 21.3% and 12.3% increased risk of mortality in the derivation and validation populations, respectively. Using sTNFR1 or IL8 to select high-risk patients improved clinical trial power and efficiency compared to selecting patients with septic shock. Ang2 did not outperform septic shock as an enrichment factor. CONCLUSIONS: Thresholds for sTNFR1 and IL8 consistently identified sepsis patients with higher mortality risk and may have utility for prognostic enrichment in sepsis trials.

Discovering Drugs with DNA-Encoded Library Technology: From Concept to Clinic with an Inhibitor of Soluble Epoxide Hydrolase.

DNA-encoded chemical library technology was developed with the vision of its becoming a transformational platform for drug discovery. The hope was that a new paradigm for the discovery of low-molecular-weight drugs would be enabled by combining the vast molecular diversity achievable with combinatorial chemistry, the information-encoding attributes of DNA, the power of molecular biology, and a streamlined selection-based discovery process. Here, we describe the discovery and early clinical development of GSK2256294, an inhibitor of soluble epoxide hydrolase (sEH, EPHX2), by using encoded-library technology (ELT). GSK2256294 is an orally bioavailable, potent and selective inhibitor of sEH that has a long half life and produced no serious adverse events in a first-time-in-human clinical study. To our knowledge, GSK2256294 is the first molecule discovered from this technology to enter human clinical testing and represents a realization of the vision that DNA-encoded chemical library technology can efficiently yield molecules with favorable properties that can be readily progressed into high-quality drugs.

Epithelial desquamation observed in a phase I study of an oral cathepsin C inhibitor (GSK2793660).

AIMS: Cathepsin C (CTSC) is necessary for the activation of several serine proteases including neutrophil elastase (NE), cathepsin G and proteinase 3. GSK2793660 is an oral, irreversible inhibitor of CTSC that is hypothesized to provide an alternative route to achieve NE inhibition and was tested in a Phase I study. METHODS: Single escalating oral doses of GSK2793660 from 0.5 to 20 mg or placebo were administered in a randomized crossover design to healthy male subjects; a separate cohort received once daily doses of 12 mg or placebo for 21 days. Data were collected on safety, pharmacokinetics, CTSC enzyme inhibition and blood biomarkers. RESULTS: Single, oral doses of GSK2793660 were able to dose-dependently inhibit whole blood CTSC activity. Once daily dosing of 12 mg GSK2793660 for 21 days achieved ≥90% inhibition (95% CI: 56, 130) of CTSC within 3 h on day 1. Only modest reductions of whole blood enzyme activity of approximately 20% were observed for NE, cathepsin G and proteinase 3. Seven of 10 subjects receiving repeat doses of GSK2793660 manifested epidermal desquamation on palmar and plantar surfaces beginning 7-10 days after dosing commencement. There were no other clinically important safety findings. CONCLUSIONS: GSK2793660 inhibited CTSC activity but not the activity of downstream neutrophil serine proteases. The palmar-plantar epidermal desquamation suggests a previously unidentified role for CTSC or one of its target proteins in the maintenance and integrity of the epidermis at these sites, with some similarities to the phenotype of CTSC-deficient humans.

A pilot clinical trial of recombinant human angiotensin-converting enzyme 2 in acute respiratory distress syndrome.

BACKGROUND: Renin-angiotensin system (RAS) signaling and angiotensin-converting enzyme 2 (ACE2) have been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS). We postulated that repleting ACE2 using GSK2586881, a recombinant form of human angiotensin-converting enzyme 2 (rhACE2), could attenuate acute lung injury. METHODS: We conducted a two-part phase II trial comprising an open-label intrapatient dose escalation and a randomized, double-blind, placebo-controlled phase in ten intensive care units in North America. Patients were between the ages of 18 and 80 years, had an American-European Consensus Criteria consensus diagnosis of ARDS, and had been mechanically ventilated for less than 72 h. In part A, open-label GSK2586881 was administered at doses from 0.1 mg/kg to 0.8 mg/kg to assess safety, pharmacokinetics, and pharmacodynamics. Following review of data from part A, a randomized, double-blind, placebo-controlled investigation of twice-daily doses of GSK2586881 (0.4 mg/kg) for 3 days was conducted (part B). Biomarkers, physiological assessments, and clinical endpoints were collected over the dosing period and during follow-up. RESULTS: Dose escalation in part A was well-tolerated without clinically significant hemodynamic changes. Part B was terminated after 39 of the planned 60 patients following a planned futility analysis. Angiotensin II levels decreased rapidly following infusion of GSK2586881, whereas angiotensin-(1-7) and angiotensin-(1-5) levels increased and remained elevated for 48 h. Surfactant protein D concentrations were increased, whereas there was a trend for a decrease in interleukin-6 concentrations in rhACE2-treated subjects compared with placebo. No significant differences were noted in ratio of partial pressure of arterial oxygen to fraction of inspired oxygen, oxygenation index, or Sequential Organ Failure Assessment score. CONCLUSIONS: GSK2586881 was well-tolerated in patients with ARDS, and the rapid modulation of RAS peptides suggests target engagement, although the study was not powered to detect changes in acute physiology or clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01597635 . Registered on 26 January 2012.

Pharmacokinetics, pharmacodynamics and adverse event profile of GSK2256294, a novel soluble epoxide hydrolase inhibitor.

AIMS: Endothelial-derived epoxyeicosatrienoic acids may regulate vascular tone and are metabolized by soluble epoxide hydrolase enzymes (sEH). GSK2256294 is a potent and selective sEH inhibitor that was tested in two phase I studies. METHODS: Single escalating doses of GSK2256294 2-20 mg or placebo were administered in a randomized crossover design to healthy male subjects or obese smokers. Once daily doses of 6 or 18 mg or placebo were administered for 14 days to obese smokers. Data were collected on safety, pharmacokinetics, sEH enzyme inhibition and blood biomarkers. Single doses of GSK2256294 10 mg were also administered to healthy younger males or healthy elderly males and females with and without food. Data on safety, pharmacokinetics and biliary metabolites were collected. RESULTS: GSK2256294 was well-tolerated with no serious adverse events (AEs) attributable to the drug. The most frequent AEs were headache and contact dermatitis. Plasma concentrations of GSK2256294 increased with single doses, with a half-life averaging 25-43 h. There was no significant effect of age, food or gender on pharmacokinetic parameters. Inhibition of sEH enzyme activity was dose-dependent, from an average of 41.9% on 2 mg (95% confidence interval [CI] -51.8, 77.7) to 99.8% on 20 mg (95% CI 99.3, 100.0) and sustained for up to 24 h. There were no significant changes in serum VEGF or plasma fibrinogen. CONCLUSIONS: GSK2256294 was well-tolerated and demonstrated sustained inhibition of sEH enzyme activity. These data support further investigation in patients with endothelial dysfunction or abnormal tissue repair, such as diabetes, wound healing or COPD.

A Randomized Dose-Escalation Study of the Safety and Anti-Inflammatory Activity of the p38 Mitogen-Activated Protein Kinase Inhibitor Dilmapimod in Severe Trauma Subjects at Risk for Acute Respiratory Distress Syndrome.

OBJECTIVES: There are no current pharmacological therapies for the prevention or treatment of acute respiratory distress syndrome. Early dysregulated inflammation likely plays a role in acute respiratory distress syndrome development and possibly acute respiratory distress syndrome outcomes. p38 mitogen-activated protein kinase is central to the regulation of multiple inflammatory mediators implicated in acute organ dysfunction and is the target for a novel class of cytokine-suppressive anti-inflammatory drugs. In preclinical models, p38 inhibitors reduce lung injury following pancreatitis and burn injury. DESIGN: We conducted a phase IIa, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the safety and tolerability of dilmapimod, a novel p38 mitogen-activated protein kinase inhibitor, in patients at risk for developing acute respiratory distress syndrome admitted with an Injury Severity Score more than 16, excluding head trauma. Enrolled patients received 4- or 24-hour IV dilmapimod infusions at different doses or placebo, daily for 3 days, in four separate cohorts. SETTING: Multicenter randomized clinical trial of large, academic trauma centers. MEASUREMENTS AND MAIN RESULTS: Seventy-seven patients were enrolled. Although adverse events were common in this critically ill population, dilmapimod was well tolerated, with no clinically relevant safety findings. Pharmacokinetic models indicated that the higher dose of 10 mg given as continuous infusion over 24 hours had the most favorable plasma concentration profile. Likewise, measures of soluble inflammatory markers including interleukin-6, C-reactive peptide, interleukin-8, and soluble tumor necrosis factor receptor 1 were most different between this dosing arm and placebo. Although the study was not specifically designed with acute respiratory distress syndrome as an outcome, the number of patients who developed acute respiratory distress syndrome was small (2/77). CONCLUSIONS: The novel p38 mitogen-activated protein kinase inhibitor dilmapimod appears well tolerated and may merit further evaluation for prevention of acute respiratory distress syndrome and other organ injury in larger clinical trials. Furthermore, results of this early-phase trial may aid in design of future studies aimed at prevention of acute respiratory distress syndrome and other organ injury.

Predictors of objective cough frequency in chronic obstructive pulmonary disease.

RATIONALE: Cough is one of the principal symptoms of chronic obstructive pulmonary disease (COPD) but the potential drivers of cough are likely to be multifactorial and poorly understood. OBJECTIVES: To quantify cough frequency in an unselected group of subjects with COPD and investigate the relationships between cough, reported sputum production, smoking, pulmonary function, and cellular airway inflammation. METHODS: We studied 68 subjects with COPD (mean age, 65.6 ± 6.7 yr; 67.6% male; 23 smokers; 45 ex-smokers) and 24 healthy volunteers (mean age, 57.5 ± 8.9 yr; 37.5% male; 12 smokers; 12 nonsmokers). Subjects reported cough severity, cough-specific quality of life, and sputum expectoration and performed spirometry, sputum induction, cough reflex sensitivity to capsaicin, and 24-hour ambulatory cough monitoring. MEASUREMENTS AND MAIN RESULTS: COPD current smokers had the highest cough rates (median, 9 coughs/h [interquartile range, 4.3-15.6 coughs/h]), almost double that of COPD ex-smokers (4.9 [2.3-8.7] coughs/h; P = 0.018) and healthy smokers (5.3 [1.2-8.3] coughs/h; P = 0.03), whereas healthy volunteers coughed the least (0.7 [0.2-1.4] coughs/h). Cough frequency was not influenced by age or sex and only weakly correlated with cough reflex sensitivity to capsaicin (log C5 r = -0.36; P = 0.004). Reported sputum production, smoking history, and current cigarette consumption strongly predicted cough frequency, explaining 45.1% variance in a general linear model (P < 0.001). In subjects producing a sputum sample, cough frequency was related to current cigarette consumption and percentage of sputum neutrophils (P = 0.002). CONCLUSIONS: Ambulatory objective monitoring provides novel insights into the determinants of cough in COPD, suggesting sputum production, smoking, and airway inflammation may be more important than sensitivity of the cough reflex.

Safety and tolerability of the inhaled phosphodiesterase 4 inhibitor GSK256066 in moderate COPD.

BACKGROUND: Inhibition of phosphodiesterase 4 (PDE4) represents an approach to anti-inflammatory therapy in chronic obstructive pulmonary disease (COPD). GSK256066 is a potent and selective inhaled PDE4 inhibitor. The aim of this study was to investigate the safety and tolerability of 28 days repeat inhaled dosing with GSK256066 in moderate COPD. METHODS: This was a Phase IIa, multicenter, parallel-group, double-blind, three-arm, placebo-controlled, four-week, randomized study with two doses of GSK256066 (25 µg, 87.5 µg). The primary endpoint was safety and tolerability. Secondary endpoints included changes in inflammatory markers in induced sputum and blood, lung function (spirometry, body plethysmography, impulse oscillometry), and pharmacokinetics. RESULTS: 104 patients were randomized and 94 patients completed the study. The incidence and intensity of treatment-related adverse events were similar between treatment groups. The most frequent adverse event was nasopharyngitis and there were no serious adverse events in patients receiving GSK256066. The overall incidence of gastrointestinal adverse events was low in all treatment groups. There were no statistically significant changes in inflammatory markers in induced sputum and blood following treatment with GSK256066. Analysis of sputum mRNA suggested engagement of pharmacology, based on increased expression of cAMP-dependent genes including amphiregulin and CREM in subjects receiving GSK256066. There was a trend for an increase in post-bronchodilator FEV1 for both doses of GSK256066; in addition, for the 87.5 µg group, there was a mean reduction in residual volume of 0.367 L (95% confidence interval: 0.112, 0.622 L) relative to placebo. CONCLUSIONS: Administration of inhaled GSK256066 was well-tolerated in patients with moderate COPD. Further studies would be required to confirm the favorable safety profile and to demonstrate clinical efficacy of this compound. (ClinicalTrials.gov identifier: NCT00549679).

Assessment of potential drug interactions by characterization of human drug metabolism pathways using non-invasive bile sampling.

AIM: Characterization of the biliary disposition of GSK1325756, using a non-invasive bile sampling technique and spectrometric analyses, to inform the major routes of metabolic elimination and to enable an assessment of victim drug interaction risk. METHOD: Sixteen healthy, elderly subjects underwent non-invasive bile capture using a peroral string device (Entero-Test(®)) prior to and following a single oral dose of GSK1325756 (100 mg). The device was swallowed by each subject and once the weighted string was judged to have reached the duodenum, gallbladder contraction was stimulated in order to release bile. The string was then retrieved via the mouth and bile samples were analyzed for drug-related material using spectrometric and spectroscopic techniques following solvent extraction. RESULTS: Nuclear magnetic resonance spectroscopy (NMR) indicated that the O-glucuronide metabolite was the major metabolite of GSK1325756, representing approximately 80% of drug-related material in bile. As bile is the major clearance route for GSK1325756 (only 4% of the administered dose was excreted in human urine), this result indicates that uridine 5'-diphospho-glucuronosyltransferases (UGTs) are the major drug metabolizing enzymes responsible for drug clearance. The relatively minor contribution made by oxidative routes reduces the concern of CYP-mediated victim drug interactions. CONCLUSION: The results from this study demonstrate the utility of deploying the Entero-Test® in early human studies to provide information on the biliary disposition of drugs and their metabolites. This technique can be readily applied in early clinical development studies to provide information on the risk of interactions for drugs that are metabolized and eliminated in bile.

Study to Explore the Association of the Renin-Angiotensin System and Right Ventricular Function in Mechanically Ventilated Patients.

BACKGROUND: Right ventricular (RV) dysfunction is associated with pulmonary vasoconstriction in mechanically ventilated patients. Enhancing the activity of angiotensin-converting enzyme 2 (ACE2), a key enzyme of the renin-angiotensin system (RAS), using recombinant human ACE2 (rhACE2) could alleviate RAS-mediated vasoconstriction and vascular remodeling. METHODS: This prospective observational study investigated the association between concentrations of RAS peptides (Ang II or Ang(1-7)) and markers of RV function, as assessed by echocardiography (ratio of RV to left ventricular end-diastolic area, interventricular septal motion, and pulmonary arterial systolic pressure (PASP)). RESULTS: Fifty-seven mechanically ventilated patients were enrolled. Incidence rates of acute cor pulmonale (ACP) and pulmonary circulatory dysfunction (PCD) were consistent with previous studies. In the 45 evaluable participants, no notable or consistent changes in RAS peptides concentration were observed over the observation period, and there was no correlation between Ang II concentration and either PASP or RV size. The model of the predicted posterior distributions for the pre- and post-dose values of Ang II demonstrated no change in the likelihood of PCD after hypothetical dosing with rhACE2, thus meeting the futility criteria. Similar results were observed with the other RAS peptides evaluated. CONCLUSIONS: Pre-defined success criteria for an association between PCD and the plasma RAS peptides were not met in the mechanically ventilated unselected patients.

An open-label, dose-escalation study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single doses of GSK2586881 in participants with pulmonary arterial hypertension.

Preclinical and early clinical studies suggest that angiotensin-converting enzyme type 2 activity may be impaired in patients with pulmonary arterial hypertension (PAH); therefore, administration of exogenous angiotensin-converting enzyme type 2 (ACE2) may be beneficial. This Phase IIa, multi-center, open-label, exploratory, single-dose, dose-escalation study (NCT03177603) assessed the potential vasodilatory effects of single doses of GSK2586881 (a recombinant human ACE2) on acute cardiopulmonary hemodynamics in hemodynamically stable adults with documented PAH who were receiving background PAH therapy. Successive cohorts of participants were administered a single intravenous dose of GSK2586881 of 0.1, 0.2, 0.4, or 0.8 mg/kg. Dose escalation occurred after four or more participants per cohort were dosed and a review of safety, tolerability, pharmacokinetics, and hemodynamic data up to 24 h postdose was undertaken. The primary endpoint was a change in cardiopulmonary hemodynamics (pulmonary vascular resistance, cardiac index, and mean pulmonary artery pressure) from baseline. Secondary/exploratory objectives included safety and tolerability, effect on renin-angiotensin system peptides, and pharmacokinetics. GSK2586881 demonstrated no consistent or sustained effect on acute cardiopulmonary hemodynamics in participants with PAH receiving background PAH therapy (N = 23). All doses of GSK2586881 were well tolerated. GSK2586881 was quantifiable in plasma for up to 4 h poststart of infusion in all participants and caused a consistent and sustained reduction in angiotensin II and a corresponding increase in angiotensin (1-7) and angiotensin (1-5). While there does not appear to be a consistent acute vasodilatory response to single doses of GSK2586881 in participants with PAH, the potential benefits in terms of chronic vascular remodeling remain to be determined.

SB-656933, a novel CXCR2 selective antagonist, inhibits ex vivo neutrophil activation and ozone-induced airway inflammation in humans.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Receptor antagonists that block the binding of chemokines such as CXCL8 (IL-8) are effective in animals models of neutrophil-mediated inflammation. It has been hypothesized that selective inhibition of neutrophil trafficking and activation may be a useful adjunct for the treatment of inflammatory airway diseases such as chronic obstructive pulmonary disease or cystic fibrosis. A CXCR1/2 receptor antagonist has shown activity in an ozone challenge model in humans. WHAT THIS STUDY ADDS: SB-656933, a selective CXCR2 antagonist, is safe and well-tolerated at single doses and is shown to inhibit agonist (CXCL1)-mediated expression of the CD11b on peripheral blood neutrophils as well as ozone-induced airway neutrophilia in healthy subjects. AIMS: To determine the safety and tolerability of a novel selective CXCR2 antagonist and assess its pharmacodynamic effects using measures of neutrophil activation and function, including CD11b expression in whole blood and ozone-induced airway inflammation in healthy subjects. METHODS: Flow cytometric determination of ex vivo CXCL1-induced CD11b expression on peripheral blood neutrophils was performed following single dose oral administration of SB-656933 (dose range 2-1100 mg). A subsequent randomized study (placebo, 50 mg and 150 mg) was performed to explore the dose-response for ozone-induced airway inflammation, as measured by sputum biomarkers. RESULTS: Oral administration of SB-656933 resulted in significant inhibition of CXCL1-induced CD11b expression on peripheral blood neutrophils at single doses greater than or equal to 50 mg. Maximum inhibition (70%) relative to placebo was observed following administration of SB-656933 400 mg (95% CI 60%, 77%). This was sustained up to a dose of 1100 mg. Single doses of SB-656933 reduced ozone-induced airway inflammation in a dose-dependent manner. Relative to placebo, there were 55% (95% CI 20%, 75%) and 74% (95% CI 55%, 85%) fewer neutrophils in the sputum of subjects after a single dose of 50 mg or 150 mg, respectively. There was a corresponding reduction in myeloperoxidase concentrations in the sputum supernatant of 32.8% (95% CI 9.2, 50.3) and 50.5% (95% CI 33.3, 63.3). SB-656933 was safe and well-tolerated at all doses. CONCLUSIONS: SB-656933 is a CXCR2 antagonist that demonstrates dose-dependent effects on neutrophil activation and recruitment within a well-tolerated dose range. These data suggest that SB-656933 may be an effective agent in neutrophil-predominant diseases.

Effects of Recombinant Human Angiotensin-Converting Enzyme 2 on Response to Acute Hypoxia and Exercise: A Randomised, Placebo-Controlled Study.

INTRODUCTION: Angiotensin-converting enzyme 2 (ACE2) is a key enzyme of the renin-angiotensin system (RAS) that has been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS). Enhancing ACE2 activity using GSK2586881, a recombinant form of human ACE2, could be beneficial in diseases such as ARDS but may blunt the hypoxic pulmonary vasoconstriction (HPV) response and potentially impact systemic and tissue oxygenation. This study aimed to evaluate the effect of GSK2586881 0.8 mg/kg on HPV response in healthy adult volunteers during exercise under hypoxic conditions. METHODS: In this phase I, randomised, double-blind (sponsor open) study, GSK2586881 or placebo was administered as a single intravenous (IV) dose in a two-period crossover design. Treatment periods were separated by a washout period of 3-14 days. The primary endpoint was change from baseline in pulmonary artery systolic pressure (PASP) measured by echocardiography. Secondary endpoints included RAS peptides and oxygen saturation. RESULTS: Seventeen adults aged 18-40 years were randomised to treatment. There were no clinically relevant differences (defined as a reduction of ≥ 5 mmHg) in change from baseline in PASP between GSK2586881 and placebo. GSK2586881 was well tolerated, with no serious adverse events, no worsening of hypoxaemia and no evidence of immunogenicity. The study was terminated early after review of the data, which showed that the predefined success criteria had not been met. Following GSK2586881 administration, levels of the RAS peptide angiotensin II decreased while angiotensin (1-7) increased, as expected, indicating that GSK2586881 was pharmacologically active. CONCLUSIONS: A single IV dose of GSK2586881 0.8 mg/kg was well tolerated but did not impact the acute HPV response in healthy volunteers.

The inhaled phosphodiesterase 4 inhibitor GSK256066 reduces allergen challenge responses in asthma.

UNLABELLED: GSK256066 is a selective phosphodiesterase 4 inhibitor that can be given by inhalation, minimising the potential for side effects. We evaluated the effects of GSK256066 on airway responses to allergen challenge in mild asthmatics. METHODS: In a randomised, double blind, cross-over study, 24 steroid naive atopic asthmatics with both early (EAR) and late (LAR) responses to inhaled allergen received inhaled GSK256066 87.5 mcg once per day and placebo for 7 days, followed by allergen challenge. Methacholine reactivity was measured 24 h post-allergen. Plasma pharmacokinetics were measured. The primary endpoint was the effect on LAR. RESULTS: GSK256066 significantly reduced the LAR, attenuating the fall in minimum and weighted mean FEV1 by 26.2% (p = 0.007) and 34.3% (p = 0.005) respectively compared to placebo. GSK256066 significantly reduced the EAR, inhibiting the fall in minimum and weighted mean FEV1 by 40.9% (p = 0.014) and 57.2% (p = 0.014) respectively compared to placebo. There was no effect on pre-allergen FEV1 or methacholine reactivity post allergen. GSK256066 was well tolerated, with low systemic exposure; plasma levels were not measurable after 4 hours in the majority of subjects. CONCLUSIONS: GSK256066 demonstrated a protective effect on the EAR and LAR. This is the first inhaled PDE4 inhibitor to show therapeutic potential in asthma.

CXCL-8-dependent and -independent neutrophil activation in COPD: experiences from a pilot study of the CXCR2 antagonist danirixin.

The implications of these findings are significant for development of CXCR2 antagonists and other mechanisms targeting neutrophil activation or NETosis, suggesting that IL-8-dependent mechanisms will only work in a subset of COPD patients https://bit.ly/32SeisO.

Defining Chronic Mucus Hypersecretion Using the CAT in the SPIROMICS Cohort.

Background: Chronic cough and phlegm are frequently reported chronic obstructive pulmonary disease (COPD) symptoms. Prior research classified chronic mucus hypersecretion (CMH) based on the presence of these symptoms for ≥3 months, called chronic bronchitis (CB) if respiratory infection symptoms were present for 1-2 years (Medical Research Council [MRC] definition). We explored whether the COPD Assessment Test (CAT), a simple measure developed for routine clinical use, captures CMH populations and outcomes similarly to MRC and St. George's Respiratory Questionnaire (SGRQ) definitions. Methods: We identified CMH in the SPIROMICS COPD cohort using (a) MRC definitions, (b) SGRQ questions for cough and phlegm (both as most/several days a week), and (c) CAT cough and phlegm questions. We determined optimal cut-points for CAT items and described exacerbation frequencies for different CMH definitions. Moderate exacerbations required a new prescription for antibiotics/oral corticosteroids or emergency department visit; severe exacerbations required hospitalization. Results were stratified by smoking status. Results: In a population of 1431 participants (57% male; mean FEV1% predicted 61%), 47% and 49% of evaluable participants had SGRQ- or CAT-defined CMH, respectively. A cut-point of ≥2 for cough and phlegm items defined CMH in CAT. Among SGRQ-CMH+ participants, 80% were also defined as CMH+ by the CAT. CMH+ participants were more likely to be current smokers. A higher exacerbation frequency was observed for presence of CMH+ versus CMH- in the year prior to baseline for all CMH definitions; this trend continued across 3 years of follow-up, regardless of smoking status. Conclusion: Items from the CAT identified SGRQ-defined CMH, a frequent COPD trait that correlated with exacerbation frequency. The CAT is a short, simple questionnaire and a potentially valuable tool for telemedicine or real-world trials. CAT-based CMH is a novel approach for identifying clinically important characteristics in COPD that can be ascertained in these settings.