CHF6001 Inhibits NF-κB activation and neutrophilic recruitment in LPS-induced lung inflammation in mice

Inhibitors of phosphodiesterase 4 (PDE4) are potent anti-inflammatory agents, inhibiting the production of inflammatory mediators through the elevation of intracellular cAMP concentrations. We studied the activity of a novel PDE4 inhibitor, CHF6001, both in vitro in human cells and in vivo, using bioluminescence imaging (BLI) in mice lung inflammation. Mice transiently transfected with the luciferase gene under the control of an NF-\u3baB responsive element (NF-\u3baB-luc) have been used to assess the in vivo anti-inflammatory activity of CHF6001 in lipopolysaccharide (LPS)-induced lung inflammation. BLI as well as inflammatory cells and the concentrations of pro-inflammatory cytokines were monitored in bronchoalveolar lavage fluids (BALF) while testing in vitro its ability to affect the production of leukotriene B4 (LTB4), measured by LC/MS/MS, by LPS/LPS/N-formyl-methionyl-leucyl-phenylalanine (fMLP)-activated human blood. CHF6001 inhibited the production of LTB4 in LPS/fMLP-activated human blood at sub-nanomolar concentrations. LPS-induced an increase of BLI signal in NF-\u3baB-luc mice, and CHF6001 administered by dry powder inhalation decreased in parallel luciferase signal, cell airway infiltration, and pro-inflammatory cytokine concentrations in BALF. The results obtained provide in vitro and in vivo evidence of the anti-inflammatory activity of the potent PDE4 inhibitor CHF6001, showing that with a topical administration that closely mimics inhalation in humans, it efficiently disrupts the NF-\u3baB activation associated with LPS challenge, an effect that may be relevant for the prevention of exacerbation episodes in chronic obstructive pulmonary disease subjects

Anti-inflammatory effects of the novel inhaled phosphodiesterase type 4 inhibitor CHF6001 on virus-inducible cytokines

Respiratory virus infections precipitate asthma and chronic obstructive pulmonary disease (COPD) exacerbations, with most exacerbations due to rhinovirus infection. Both asthma and COPD exacerbations are not well controlled by steroid therapies, and there is a much research interest in finding improved therapies or combinations of therapies for controlling exacerbations. CHF6001 is a new, inhaled highly potent and selective phosphodiesterase type 4 (PDE4) inhibitor. Using in vitro human bronchial epithelial cells (BEAS-2B), we investigated the potential anti-inflammatory effects of CHF6001 on rhinovirus (RV1B)-induced cytokines. Cytokine mRNA was measured by real-time PCR, while protein release was measured by ELISA. CHF6001 was used in a 7-point dose–response curve (1000–0.001 nmol/L) as a 1.5-h pretreatment prior to infection in comparison with roflumilast. Both roflumilast and CHF6001 reduced RV1B-induced IL-8, IL-29, IP-10, and RANTES mRNA and protein in a concentration-dependent manner. Generally, CHF6001 was 13- to 16-fold more potent (subnanomolar EC50 values) than roflumilast at reducing IL-8, IL-29, IP-10, and RANTES mRNA and protein release, but had similar efficacies. In combination with the steroid fluticasone propionate (1 nmol/L), CHF6001 had additive effects, significantly reducing RV-induced cytokines when compared with steroid or CHF6001 alone. Combined low-dose steroid and low-dose CHF6001 had a similar efficacy as high-dose steroid or CHF6001 alone, indicating the combination had steroid and PDE4 inhibitor sparing effects. Overall results indicate that PDE4 inhibitors have anti-inflammatory activity against virus-induced inflammatory mediators and that CHF6001 is more potent than roflumilast

QTc prolongation assessment in anticancer drug development: clinical and methodological issues

Cardiac safety assessments are commonly employed in the clinical development of investigational oncology medications. In anti-cancer drug development there has been increasing consideration for the potential of a compound to cause adverse electrocardiographic changes, especially QT interval prolongation, which can be associated with risk of torsades de pointes and sudden death. Irrespective of overt clinical toxicities, QTc assessment can potentially influence decision making at many levels during the conduct of clinical studies, including eligibility for protocol therapy, dose delivery or discontinuation, and analyses of optimal dose for subsequent development. Given the potential for serious and irreversible morbidity from cardiac adverse events, it is understandable that cardiac safety results can have broad impact on study conduct and patient management. The methodologies for risk management of QTc prolongation for non cardiac drugs have been developed out of experiences primarily from drugs used to treat non life-threatening illnesses in a chronic setting such as antibiotics or antihistamines. Extrapolating these approaches to drugs for treating cancer over an acute period may not be appropriate. Few specific guidelines are available for risk management of cardiac safety in the development and use of oncology drugs. In this manuscript, clinical and methodological issues related to QTc prolongation assessment will be reviewed. Discussions about limitations in phase-I design and oncology drug development will be highlighted. Efforts are needed to refine strategies for risk management, avoiding unintended consequences that negatively affect patient access and clinical development of promising new cancer treatments. A thoughtful risk management plan generated by an organized collaboration between oncologists, cardiologists, and regulatory agencies to support a development programme essential for oncology agents with cardiac safety concerns

Monitoring inflammation and airway remodeling by fluorescence molecular tomography in a chronic asthma model

Background: Asthma is a multifactorial disease for which a variety of mouse models have been developed. A major drawback of these models is represented by the transient nature of the airway pathology peaking 24-72h after challenge and resolving in 1-2weeks. We characterized the temporal evolution of pulmonary inflammation and tissue remodeling in a recently described mouse model of chronic asthma (8week treatment with 3 allergens: Dust mite, Ragweed, and Aspergillus; DRA). Methods: We studied the DRA model taking advantage of fluorescence molecular tomography (FMT) imaging using near-infrared probes to non-invasively evaluate lung inflammation and airway remodeling. At 4, 6, 8 or 11weeks, cathepsin- and metalloproteinase-dependent fluorescence was evaluated in vivo. A subgroup of animals, after 4weeks of DRA, was treated with Budesonide (100\u3bcg/kg intranasally) daily for 4weeks. Results: Cathepsin-dependent fluorescence in DRA-sensitized mice resulted significantly increased at 6 and 8weeks, and was markedly inhibited by budesonide. This fluorescent signal well correlated with ex vivo analysis such as bronchoalveolar lavage eosinophils and pulmonary inflammatory cell infiltration. Metalloproteinase-dependent fluorescence was significantly increased at 8 and 11weeks, nicely correlated with collagen deposition, as evaluated histologically by Masson's Trichrome staining, and airway epithelium hypertrophy, and was only partly inhibited by budesonide. Conclusions: FMT proved suitable for longitudinal studies to evaluate asthma progression, showing that cathepsin activity could be used to monitor inflammatory cell infiltration while metalloproteinase activity parallels airway remodeling, allowing the determination of steroid treatment efficacy in a chronic asthma model in mice

Universality of pseudogap and emergent order in lightly doped Mott insulators

It is widely believed that high-temperature superconductivity in the cuprates emerges from doped Mott insulators. The physics of the parent state seems deceivingly simple: The hopping of the electrons from site to site is prohibited because their on-site Coulomb repulsion U is larger than the kinetic energy gain t. When doping these materials by inserting a small percentage of extra carriers, the electrons become mobile but the strong correlations from the Mott state are thought to survive; inhomogeneous electronic order, a mysterious pseudogap and, eventually, superconductivity appear. How the insertion of dopant atoms drives this evolution is not known, nor whether these phenomena are mere distractions specific to hole-doped cuprates or represent the genuine physics of doped Mott insulators. Here, we visualize the evolution of the electronic states of (Sr1-xLax)2IrO4, which is an effective spin-1/2 Mott insulator like the cuprates, but is chemically radically different. Using spectroscopic-imaging STM, we find that for doping concentration of x=5%, an inhomogeneous, phase separated state emerges, with the nucleation of pseudogap puddles around clusters of dopant atoms. Within these puddles, we observe the same glassy electronic order that is so iconic for the underdoped cuprates. Further, we illuminate the genesis of this state using the unique possibility to localize dopant atoms on topographs in these samples. At low doping, we find evidence for much deeper trapping of carriers compared to the cuprates. This leads to fully gapped spectra with the chemical potential at mid-gap, which abruptly collapse at a threshold of around 4%. Our results clarify the melting of the Mott state, and establish phase separation and electronic order as generic features of doped Mott insulators.Comment: This version contains the supplementary information and small updates on figures and tex

From bench to bedside: in vitro and in vivo evaluation of a neonate-focused nebulized surfactant delivery strategy.

BACKGROUND: Non-invasive delivery of nebulized surfactant has been a neonatology long-pursued goal. Nevertheless, the clinical efficacy of nebulized surfactant remains inconclusive, in part, due to the great technical challenges of depositing nebulized drugs in the lungs of preterm infants. The aim of this study was to investigate the feasibility of delivering nebulized surfactant (poractant alfa) in vitro and in vivo with an adapted, neonate-tailored aerosol delivery strategy. METHODS: Particle size distribution of undiluted poractant alfa aerosols generated by a customized eFlow-Neos nebulizer system was determined by laser diffraction. The theoretical nebulized surfactant lung dose was estimated in vitro in a clinical setting replica including a neonatal continuous positive airway pressure (CPAP) circuit, a cast of the upper airways of a preterm neonate, and a breath simulator programmed with the tidal breathing pattern of an infant with mild respiratory distress syndrome (RDS). A dose-response study with nebulized surfactant covering the 100-600\u2009mg/kg nominal dose-range was conducted in RDS-modelling, lung-lavaged spontaneously-breathing rabbits managed with nasal CPAP. The effects of nebulized poractant alfa on arterial gas exchange and lung mechanics were assessed. Exogenous alveolar disaturated-phosphatidylcholine (DSPC) in the lungs was measured as a proxy of surfactant deposition efficacy. RESULTS: Laser diffraction studies demonstrated suitable aerosol characteristics for inhalation (mass median diameter, MMD\u2009=\u20093\u2009\u3bcm). The mean surfactant lung dose determined in vitro was 13.7%\u2009\ub1\u20094.0 of the 200\u2009mg/kg nominal dose. Nebulized surfactant delivered to spontaneously-breathing rabbits during nasal CPAP significantly improved arterial oxygenation compared to animals receiving CPAP only. Particularly, the groups of animals treated with 200\u2009mg/kg and 400\u2009mg/kg of nebulized poractant alfa achieved an equivalent pulmonary response in terms of oxygenation and lung mechanics as the group of animals treated with instilled surfactant (200\u2009mg/kg). CONCLUSIONS: The customized eFlow-Neos vibrating-membrane nebulizer system efficiently generated respirable aerosols of undiluted poractant alfa. Nebulized surfactant delivered at doses of 200\u2009mg/kg and 400\u2009mg/kg elicited a pulmonary response equivalent to that observed after treatment with an intratracheal surfactant bolus of 200\u2009mg/kg. This bench-characterized nebulized surfactant delivery strategy is now under evaluation in Phase II clinical trial (EUDRACT No.:2016-004547-36)

From bench to bedside: In vitro and in vivo evaluation of a neonate-focused nebulized surfactant delivery strategy

Background: Non-invasive delivery of nebulized surfactant has been a neonatology long-pursued goal. Nevertheless, the clinical efficacy of nebulized surfactant remains inconclusive, in part, due to the great technical challenges of depositing nebulized drugs in the lungs of preterm infants. The aim of this study was to investigate the feasibility of delivering nebulized surfactant (poractant alfa) in vitro and in vivo with an adapted, neonate- tailored aerosol delivery strategy. Methods: Particle size distribution of undiluted poractant alfa aerosols generated by a customized eFlow-Neos nebulizer system was determined by laser diffraction. The theoretical nebulized surfactant lung dose was estimated in vitro in a clinical setting replica including a neonatal continuous positive airway pressure (CPAP) circuit, a cast of the upper airways of a preterm neonate, and a breath simulator programmed with the tidal breathing pattern of an infant with mild respiratory distress syndrome (RDS). A dose-response study with nebulized surfactant covering the 100\u2013600 mg/kg nominal dose-range was conducted in RDS-modelling, lung-lavaged spontaneously-breathing rabbits managed with nasal CPAP. The effects of nebulized poractant alfa on arterial gas exchange and lung mechanics were assessed. Exogenous alveolar disaturated-phosphatidylcholine (DSPC) in the lungs was measured as a proxy of surfactant deposition efficacy. Results: Laser diffraction studies demonstrated suitable aerosol characteristics for inhalation (mass median diameter, MMD = 3 \u3bcm). The mean surfactant lung dose determined in vitro was 13.7% \ub1 4.0 of the 200 mg/kg nominal dose. Nebulized surfactant delivered to spontaneously-breathing rabbits during nasal CPAP significantly improved arterial oxygenation compared to animals receiving CPAP only. Particularly, the groups of animals treated with 200 mg/kg and 400 mg/kg of nebulized poractant alfa achieved an equivalent pulmonary response in terms of oxygenation and lung mechanics as the group of animals treated with instilled surfactant (200 mg/kg). Conclusions: The customized eFlow-Neos vibrating-membrane nebulizer system efficiently generated respirable aerosols of undiluted poractant alfa. Nebulized surfactant delivered at doses of 200 mg/kg and 400 mg/kg elicited a pulmonary response equivalent to that observed after treatment with an intratracheal surfactant bolus of 200 mg/kg. This bench-characterized nebulized surfactant delivery strategy is now under evaluation in Phase II clinical trial (EUDRACT No.:2016\u2013004547-36)

The 3-Band Hubbard-Model versus the 1-Band Model for the high-Tc Cuprates: Pairing Dynamics, Superconductivity and the Ground-State Phase Diagram

One central challenge in high-$T_c$ superconductivity (SC) is to derive a detailed understanding for the specific role of the $Cu$-$d_{x^2-y^2}$ and $O$-$p_{x,y}$ orbital degrees of freedom. In most theoretical studies an effective one-band Hubbard (1BH) or t-J model has been used. Here, the physics is that of doping into a Mott-insulator, whereas the actual high-$T_c$ cuprates are doped charge-transfer insulators. To shed light on the related question, where the material-dependent physics enters, we compare the competing magnetic and superconducting phases in the ground state, the single- and two-particle excitations and, in particular, the pairing interaction and its dynamics in the three-band Hubbard (3BH) and 1BH-models. Using a cluster embedding scheme, i.e. the variational cluster approach (VCA), we find which frequencies are relevant for pairing in the two models as a function of interaction strength and doping: in the 3BH-models the interaction in the low- to optimal-doping regime is dominated by retarded pairing due to low-energy spin fluctuations with surprisingly little influence of inter-band (p-d charge) fluctuations. On the other hand, in the 1BH-model, in addition a part comes from "high-energy" excited states (Hubbard band), which may be identified with a non-retarded contribution. We find these differences between a charge-transfer and a Mott insulator to be renormalized away for the ground-state phase diagram of the 3BH- and 1BH-models, which are in close overall agreement, i.e. are "universal". On the other hand, we expect the differences - and thus, the material dependence to show up in the "non-universal" finite-T phase diagram ($T_c$-values).Comment: 17 pages, 9 figure

Two Energy Scales and two Quasiparticle Dynamics in the Superconducting State of Underdoped Cuprates

The superconducting state of underdoped cuprates is often described in terms of a single energy-scale, associated with the maximum of the (d-wave) gap. Here, we report on electronic Raman scattering results, which show that the gap function in the underdoped regime is characterized by two energy scales, depending on doping in opposite manners. Their ratios to the maximum critical temperature are found to be universal in cuprates. Our experimental results also reveal two different quasiparticle dynamics in the underdoped superconducting state, associated with two regions of momentum space: nodal regions near the zeros of the superconducting gap and antinodal regions. While antinodal quasiparticles quickly loose coherence as doping is reduced, coherent nodal quasiparticles persist down to low doping levels. A theoretical analysis using a new sum-rule allows us to relate the low-frequency-dependence of the Raman response to the temperature-dependence of the superfluid density, both controlled by nodal excitations.Comment: 16 pages, 5 figure

Strong electronic correlations in superconducting organic charge transfer salts

We review the role of strong electronic correlations in quasi--two-dimensional organic charge transfer salts such as (BEDT-TTF)$_2X$, (BETS)$_2Y$ and $\beta'$-[Pd(dmit)$_2$]$_2Z$. We begin by defining minimal models for these materials. It is necessary to identify two classes of material: the first class is strongly dimerised and is described by a half-filled Hubbard model; the second class is not strongly dimerised and is described by a quarter filled extended Hubbard model. We argue that these models capture the essential physics of these materials. We explore the phase diagram of the half-filled quasi--two-dimensional organic charge transfer salts, focusing on the metallic and superconducting phases. We review work showing that the metallic phase, which has both Fermi liquid and `bad metal' regimes, is described both quantitatively and qualitatively by dynamical mean field theory (DMFT). The phenomenology of the superconducting state is still a matter of contention. We critically review the experimental situation, focusing on the key experimental results that may distinguish between rival theories of superconductivity, particularly probes of the pairing symmetry and measurements of the superfluid stiffness. We then discuss some strongly correlated theories of superconductivity, in particular, the resonating valence bond (RVB) theory of superconductivity. We conclude by discussing some of the major challenges currently facing the field.Comment: A review: 52 pages; 10 fig