PCSK6 and Survival in Idiopathic Pulmonary Fibrosis.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by limited treatment options and high mortality. A better understanding of the molecular drivers of IPF progression is needed. Objectives: To identify and validate molecular determinants of IPF survival. Methods: A staged genome-wide association study was performed using paired genomic and survival data. Stage I cases were drawn from centers across the United States and Europe and stage II cases from Vanderbilt University. Cox proportional hazards regression was used to identify gene variants associated with differential transplantation-free survival (TFS). Stage I variants with nominal significance (P < 5 × 10-5) were advanced for stage II testing and meta-analyzed to identify those reaching genome-wide significance (P < 5 × 10-8). Downstream analyses were performed for genes and proteins associated with variants reaching genome-wide significance. Measurements and Main Results: After quality controls, 1,481 stage I cases and 397 stage II cases were included in the analysis. After filtering, 9,075,629 variants were tested in stage I, with 158 meeting advancement criteria. Four variants associated with TFS with consistent effect direction were identified in stage II, including one in an intron of PCSK6 (proprotein convertase subtilisin/kexin type 6) reaching genome-wide significance (hazard ratio, 4.11 [95% confidence interval, 2.54-6.67]; P = 9.45 × 10-9). PCSK6 protein was highly expressed in IPF lung parenchyma. PCSK6 lung staining intensity, peripheral blood gene expression, and plasma concentration were associated with reduced TFS. Conclusions: We identified four novel variants associated with IPF survival, including one in PCSK6 that reached genome-wide significance. Downstream analyses suggested that PCSK6 protein plays a potentially important role in IPF progression.

Cluster analysis of transcriptomic datasets to identify endotypes of idiopathic pulmonary fibrosis.

BACKGROUND: Considerable clinical heterogeneity in idiopathic pulmonary fibrosis (IPF) suggests the existence of multiple disease endotypes. Identifying these endotypes would improve our understanding of the pathogenesis of IPF and could allow for a biomarker-driven personalised medicine approach. We aimed to identify clinically distinct groups of patients with IPF that could represent distinct disease endotypes. METHODS: We co-normalised, pooled and clustered three publicly available blood transcriptomic datasets (total 220 IPF cases). We compared clinical traits across clusters and used gene enrichment analysis to identify biological pathways and processes that were over-represented among the genes that were differentially expressed across clusters. A gene-based classifier was developed and validated using three additional independent datasets (total 194 IPF cases). FINDINGS: We identified three clusters of patients with IPF with statistically significant differences in lung function (p=0.009) and mortality (p=0.009) between groups. Gene enrichment analysis implicated mitochondrial homeostasis, apoptosis, cell cycle and innate and adaptive immunity in the pathogenesis underlying these groups. We developed and validated a 13-gene cluster classifier that predicted mortality in IPF (high-risk clusters vs low-risk cluster: HR 4.25, 95% CI 2.14 to 8.46, p=3.7×10-5). INTERPRETATION: We have identified blood gene expression signatures capable of discerning groups of patients with IPF with significant differences in survival. These clusters could be representative of distinct pathophysiological states, which would support the theory of multiple endotypes of IPF. Although more work must be done to confirm the existence of these endotypes, our classifier could be a useful tool in patient stratification and outcome prediction in IPF.

CYFRA 21-1 Predicts Progression in Idiopathic Pulmonary Fibrosis: A Prospective Longitudinal Analysis of the PROFILE Cohort.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a progressive and inevitably fatal condition for which there are a lack of effective biomarkers to guide therapeutic decision making. Objectives: To determine the relationship between serum concentrations of the cytokeratin fragment CYFRA 21-1 and disease progression and mortality in individuals with IPF enrolled in the Prospective Observation of Fibrosis in the Lung Clinical Endpoints (PROFILE) study. Methods: CYFRA 21-1 was identified by immunohistochemistry in samples of human lung obtained at surgery. Concentrations of CYFRA 21-1 were measured using an ELISA-based assay in serum samples collected at baseline, 1 month, and 3 months from 491 individuals with an incident diagnosis of IPF who were enrolled in the PROFILE study and from 100 control subjects at baseline. Study subjects were followed for a minimum of 3 years after their first blood draw. Measurements and Main Results: CYFRA 21-1 localizes to hyperplastic epithelium in IPF lung tissue. Peripheral CYFRA 21-1 concentrations were significantly higher in subjects with IPF than in healthy control subjects in both the discovery (n = 132) (control: 0.96 ± 0.81 ng/ml; vs. IPF: 2.34 ± 2.15 ng/ml; P < 0.0001) and validation (n = 359) (control: 2.21 ± 1.54 ng/ml; and IPF: 4.13 ± 2.77 ng/ml; P < 0.0001) cohorts. Baseline concentrations of CYFRA 21-1 were able to distinguish individuals at risk of 12-month disease progression (C-statistic, 0.70; 95% confidence interval, 0.61-0.79; P < 0.0001) and were predictive of overall mortality (hazard ratio, 1.12 [95% confidence interval, 1.06-1.19] per 1 ng/ml increase in CYFRA 21-1; P = 0.0001). Furthermore, 3-month change in concentrations of CYFRA 21-1 separately predicted 12-month and overall survival in both the discovery and validation cohorts. Conclusions: CYFRA 21-1, a marker of epithelial damage and turnover, has the potential to be an important prognostic and therapeutic biomarker in individuals with IPF.

A randomized study of the safety and pharmacokinetics of GSK3358699, a mononuclear myeloid-targeted bromodomain and extra-terminal domain inhibitor.

AIMS: GSK3358699 is a mononuclear myeloid-targeted bromodomain and extra-terminal domain (BET) family inhibitor which demonstrates immunomodulatory effects in vitro. This phase 1, randomized, first-in-human study evaluated the safety, pharmacokinetics, and pharmacodynamics of GSK3358699 in healthy male participants (NCT03426995). METHODS: Part A (N = 23) included three dose-escalating periods of 1-40 mg of GSK3358699 or placebo in two cohorts in a single ascending-dose crossover design. Part C (N = 25) was planned as an initial dose of 10 mg of GSK3358699 or placebo daily for 14 days followed by selected doses in four sequential cohorts. RESULTS: In part A, exposure to GSK3358699 and its metabolite GSK3206944 generally increased with increasing doses. The median initial half-life ranged from 0.7 to 1.1 (GSK3358699) and 2.1 to 2.9 (GSK3206944) hours after a single dose of 1-40 mg. GSK3206944 concentrations in monocytes were quantifiable at 1-hour post-dose following 10 mg of GSK3358699 and 1 and 4 hours post-dose following 20-40 mg. Mean predicted percentage inhibition of ex vivo lipopolysaccharide-induced monocyte chemoattractant protein (MCP)-1 reached 75% with 40 mg of GSK3358699. GSK3358699 did not inhibit interleukin (IL)-6 and tumour necrosis factor (TNF). The most common adverse event (AE) was headache. Four AEs of nonsustained ventricular tachycardia were observed across parts A and C. One serious AE of atrial fibrillation (part C) required hospitalization. CONCLUSIONS: Single doses of GSK3358699 are generally well tolerated with significant metabolite concentrations detected in target cells. A complete assessment of pharmacodynamics was limited by assay variability. A causal relationship could not be excluded for cardiac-related AEs, resulting in an inability to identify a suitable repeat-dose regimen and study termination.

Genome-Wide Association Study of Susceptibility to Idiopathic Pulmonary Fibrosis.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex lung disease characterized by scarring of the lung that is believed to result from an atypical response to injury of the epithelium. Genome-wide association studies have reported signals of association implicating multiple pathways including host defense, telomere maintenance, signaling, and cell-cell adhesion.Objectives: To improve our understanding of factors that increase IPF susceptibility by identifying previously unreported genetic associations.Methods: We conducted genome-wide analyses across three independent studies and meta-analyzed these results to generate the largest genome-wide association study of IPF to date (2,668 IPF cases and 8,591 controls). We performed replication in two independent studies (1,456 IPF cases and 11,874 controls) and functional analyses (including statistical fine-mapping, investigations into gene expression, and testing for enrichment of IPF susceptibility signals in regulatory regions) to determine putatively causal genes. Polygenic risk scores were used to assess the collective effect of variants not reported as associated with IPF.Measurements and Main Results: We identified and replicated three new genome-wide significant (P < 5 × 10-8) signals of association with IPF susceptibility (associated with altered gene expression of KIF15, MAD1L1, and DEPTOR) and confirmed associations at 11 previously reported loci. Polygenic risk score analyses showed that the combined effect of many thousands of as yet unreported IPF susceptibility variants contribute to IPF susceptibility.Conclusions: The observation that decreased DEPTOR expression associates with increased susceptibility to IPF supports recent studies demonstrating the importance of mTOR signaling in lung fibrosis. New signals of association implicating KIF15 and MAD1L1 suggest a possible role of mitotic spindle-assembly genes in IPF susceptibility.

A positron emission tomography imaging study to confirm target engagement in the lungs of patients with idiopathic pulmonary fibrosis following a single dose of a novel inhaled αvß6 integrin inhibitor.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease with poor prognosis and a significant unmet medical need. This study evaluated the safety, pharmacokinetics (PK) and target engagement in the lungs, of GSK3008348, a novel inhaled alpha-v beta-6 (αvß6) integrin inhibitor, in participants with IPF. METHODS: This was a phase 1b, randomised, double-blind (sponsor unblind) study, conducted in the UK (two clinical sites, one imaging unit) between June 2017 and July 2018 (NCT03069989). Participants with a definite or probable diagnosis of IPF received a single nebulised dose of 1000 mcg GSK3008348 or placebo (ratio 5:2) in two dosing periods. In period 1, safety and PK assessments were performed up to 24 h post-dose; in period 2, after a 7-day to 28-day washout, participants underwent a total of three positron emission tomography (PET) scans: baseline, Day 1 (~ 30 min post-dosing) and Day 2 (~ 24 h post-dosing), using a radiolabelled αvß6-specific ligand, [18F]FB-A20FMDV2. The primary endpoint was whole lung volume of distribution (VT), not corrected for air volume, at ~ 30 min post-dose compared with pre-dose. The study success criterion, determined using Bayesian analysis, was a posterior probability (true % reduction in VT > 0%) of ≥80%. RESULTS: Eight participants with IPF were enrolled and seven completed the study. Adjusted posterior median reduction in uncorrected VT at ~ 30 min after GSK3008348 inhalation was 20% (95% CrI: - 9 to 42%). The posterior probability that the true % reduction in VT > 0% was 93%. GSK3008348 was well tolerated with no reports of serious adverse events or clinically significant abnormalities that were attributable to study treatment. PK was successfully characterised showing rapid absorption followed by a multiphasic elimination. CONCLUSIONS: This study demonstrated engagement of the αvß6 integrin target in the lung following nebulised dosing with GSK3008348 to participants with IPF. To the best of our knowledge this is the first time a target-specific PET radioligand has been used to assess target engagement in the lung, not least for an inhaled drug. TRIAL REGISTRATION: clinicaltrials.gov: NCT03069989; date of registration: 3 March 2017.

Clinical quantification of the integrin αvß6 by [18F]FB-A20FMDV2 positron emission tomography in healthy and fibrotic human lung (PETAL Study).

PURPOSE: The RGD-integrin, αvß6, plays a role in the pathogenesis of pulmonary fibrosis through activation of transforming growth factor beta (TGFß). This study sought to quantify expression of αvß6 in the lungs of healthy humans and subjects with pulmonary fibrosis using the αvß6-selective [18F]FB-A20FMDV2 PET ligand. METHODS: [18F]FB-A20FMDV2 PET/CT scans were performed in healthy subjects and those with fibrotic lung disease. Standard uptake values (SUV) and volume of distribution (VT) were used to quantify αvß6 expression. In subjects with fibrotic lung disease, qualitative assessment of the relationship between αvß6 expression and the distribution of fibrosis on high resolution computed tomography was conducted. RESULTS: A total of 15 participants (6 healthy, 7 with idiopathic pulmonary fibrosis (IPF) and 2 with connective tissue disease (CTD) associated PF) were enrolled. VT and SUV of [18F]FB-A20FMDV2 were increased in the lungs of subjects with pulmonary fibrosis (PF) compared with healthy subjects. Geometric mean VT (95% CI) was 0.88 (0.60, 1.29) mL/cm3 for healthy subjects, and 1.40 (1.22, 1.61) mL/cm3 for subjects with IPF; and SUV was 0.54 (0.36, 0.81) g/mL for healthy subjects and 1.03 (0.86, 1.22) g/mL for subjects with IPF. The IPF/healthy VT ratio (geometric mean, (95% CI of ratio)) was 1.59 (1.09, 2.32) (probability ratio > 1 = 0.988)) and the SUV ratio was 1.91 (1.27, 2.87) (probability ratio > 1 = 0.996). Increased uptake of [18F]FB-A20FMDV2 in PF was predominantly confined to fibrotic areas. [18F]FB-A20FMDV2 measurements were reproducible at an interval of 2 weeks. [18F]FB-A20FMDV2 was safe and well tolerated. CONCLUSIONS: Lung uptake of [18F]FB-A20FMDV2, a measure of expression of the integrin αvß6, was markedly increased in subjects with PF compared with healthy subjects.

Patient-reported distress can aid clinical decision-making in idiopathic pulmonary fibrosis: analysis of the PROFILE cohort.

Idiopathic pulmonary fibrosis is a progressive and fatal interstitial lung disease. We aimed to determine if patient response to a palliative assessment survey could predict disease progression or death.We undertook a cross-sectional study in a UK clinical cohort of incident cases. Rasch-based methodology provided a disease distress value from an abridged 11-item model of the original 45-item survey. Distress values were compared with measures of lung function. Disease progression or mortality alone was predicted at 12 months from survey completion, with risk of death assessed at 3, 6 and 12 months.Disease distress values were negatively correlated with lung function (r=-0.275 for the percentage predicted diffusing capacity of the lung for carbon monoxide). Expected survey scores computed from distress values could distinguish disease progression (n=8.8, p=0.004) and death (n=10.2, p=0.002) from no disease progression (n=6.9). Actual survey scores predicted disease progression and death with an area under the curve of 0.60 and 0.64, respectively. Each point increment in actual score increased risk of 12-month mortality by 10%; almost 43% of people scoring above 18 did not survive beyond 105 days.We define a short questionnaire that can score disease distress and predict prognosis, thus assisting clinical decision-making in progressive fibrosis.

A randomised, placebo-controlled study of omipalisib (PI3K/mTOR) in idiopathic pulmonary fibrosis.

Phosphatidylinositol 3-kinases (PI3Ks) and mammalian target of rapamycin (mTOR) play a role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Omipalisib (GSK2126458) is a potent inhibitor of PI3K/mTOR.A randomised, placebo-controlled, double-blind, repeat dose escalation, experimental medicine study of omipalisib in subjects with IPF was conducted (NCT01725139) to test safety, tolerability, pharmacokinetics and pharmacodynamics. Omipalisib was dosed at 0.25 mg, 1 mg and 2 mg twice daily for 8 days in four cohorts of four subjects randomised 3:1 to receive omipalisib or placebo (two cohorts received 2 mg twice daily).17 subjects with IPF were enrolled. The most common adverse event was diarrhoea, which was reported by four participants. Dose-related increases in insulin and glucose were observed. Pharmacokinetic analysis demonstrated that exposure in the blood predicts lung exposure. Exposure-dependent inhibition of phosphatidylinositol 3,4,5 trisphosphate and pAKT confirmed target engagement in blood and lungs. 18F-2-fluoro-2-deoxy-d-glucose(FDG)-positron emission tomography/computed tomography scans revealed an exposure-dependent reduction in 18F-FDG uptake in fibrotic areas of the lung, as measured by target-to-background, ratio thus confirming pharmacodynamic activity.This experimental medicine study demonstrates acceptable tolerability of omipalisib in subjects with IPF at exposures for which target engagement was confirmed both systemically and in the lungs.

Phosphatidylinositol 3-kinase delta pathway: a novel therapeutic target for Sjögren's syndrome.

BACKGROUND: The phosphatidylinositol 3-kinase delta isoform (PI3Kδ) belongs to an intracellular lipid kinase family that regulate lymphocyte metabolism, survival, proliferation, apoptosis and migration and has been successfully targeted in B-cell malignancies. Primary Sjögren's syndrome (pSS) is a chronic immune-mediated inflammatory disease characterised by exocrine gland lymphocytic infiltration and B-cell hyperactivation which results in systemic manifestations, autoantibody production and loss of glandular function. Given the central role of B cells in pSS pathogenesis, we investigated PI3Kδ pathway activation in pSS and the functional consequences of blocking PI3Kδ in a murine model of focal sialoadenitis that mimics some features of pSS. METHODS AND RESULTS: Target validation assays showed significant expression of phosphorylated ribosomal protein S6 (pS6), a downstream mediator of the phosphatidylinositol 3-kinase delta (PI3Kδ) pathway, within pSS salivary glands. pS6 distribution was found to co-localise with T/B cell markers within pSS aggregates and the CD138+ plasma cells infiltrating the glands. In vivo blockade of PI3Kδ activity with seletalisib, a PI3Kδ-selective inhibitor, in a murine model of focal sialoadenitis decreased accumulation of lymphocytes and plasma cells within the glands of treated mice in the prophylactic and therapeutic regimes. Additionally, production of lymphoid chemokines and cytokines associated with ectopic lymphoneogenesis and, remarkably, saliva flow and autoantibody production, were significantly affected by treatment with seletalisib. CONCLUSION: These data demonstrate activation of PI3Kδ pathway within the glands of patients with pSS and its contribution to disease pathogenesis in a model of disease, supporting the exploration of the therapeutic potential of PI3Kδ pathway inhibition in this condition.

An Innovative Approach to Characterize Clinical ADME and Pharmacokinetics of the Inhaled Drug Nemiralisib Using an Intravenous Microtracer Combined with an Inhaled Dose and an Oral Radiolabel Dose in Healthy Male Subjects.

An innovative open-label, crossover clinical study was used to investigate the excretion balance, pharmacokinetics, and metabolism of nemiralisib-an inhaled phosphoinositide 3-kinase delta inhibitor being developed for respiratory diseases. Six healthy men received a single intravenous microtracer of 10 µg [14C]nemiralisib with a concomitant inhaled nonradiolabeled 1000 µg dose followed by an oral 800 µg dose of [14C]nemiralisib 14 days later. Complementary methods including accelerator mass spectrometry allowed characterization of a range of parameters including oral absorption (Fabs), proportion of nemiralisib escaping gut wall metabolism (Fg), hepatic extraction (Eh), fraction of dose absorbed from inhaled dose (Flung), and renal clearance. Intravenous pharmacokinetics of nemiralisib were characterized by low blood clearance (10.0 l/h), long terminal half-life (55 hours), and high volume of distribution at steady state (728 l). Nemiralisib exhibited moderate inhaled and oral bioavailability (38% and 35%) while Flung was 29%. Absorption and first-pass parameters were corrected for blood renal clearance and compared with values without correction. Any swallowed nemiralisib was relatively well absorbed (Fabs, 0.48) with a high fraction escaping gut wall metabolism and low extraction by the liver (Fg and Eh being 0.83 and 0.10, respectively). There were no major human plasma metabolites requiring further qualification in animal studies. Both unchanged nemiralisib and its oxidative/conjugative metabolites were secreted in bile, with nemiralisib likely subject to further metabolism through enterohepatic recirculation. Direct renal clearance and metabolism followed by renal clearance were lesser routes of elimination. SIGNIFICANCE STATEMENT: A number of innovative features have been combined into one small clinical study enabling a comprehensive description of the human pharmacokinetics and metabolism of an inhaled molecule. Design elements included an intravenous 14C tracer administration concomitant with an inhalation dose that enabled derivation of parameters such as fraction absorbed (Fabs), the proportion of drug escaping first-pass extraction through the gut wall and liver (Fg and Fh) and hepatic extraction (Eh). Entero-test bile sampling enabled characterization of biliary elimination pathways.

Biomarkers of collagen synthesis predict progression in the PROFILE idiopathic pulmonary fibrosis cohort.

Idiopathic pulmonary fibrosis (IPF) is characterised by excessive extracellular matrix (ECM) deposition and remodelling. Measuring this activity provides an opportunity to develop tools capable of identifying individuals at-risk of progression. Longitudinal change in markers of ECM synthesis was assessed in 145 newly-diagnosed individuals with IPF.Serum levels of collagen synthesis neoepitopes, PRO-C3 and PRO-C6 (collagen type 3 and 6), were elevated in IPF compared with controls at baseline, and progressive disease versus stable disease during follow up, (PRO-C3 p < 0.001; PRO-C6 p = 0.029). Assessment of rate of change in neoepitope levels from baseline to 3 months (defined as 'slope to month 3': HIGH slope, slope > 0 vs. LOW slope, slope < =0) demonstrated no relationship with mortality for these markers (PRO-C3 (HR 1.62, p = 0.080); PINP (HR 0.76, p = 0.309); PRO-C6 (HR 1.14, p = 0.628)). As previously reported, rising concentrations of collagen degradation markers C1M, C3M, C6M and CRPM were associated with an increased risk of overall mortality (HR = 1.84, CI 1.03-3.27, p = 0.038, HR = 2.44, CI 1.39-4.31, p = 0.002; HR = 2.19, CI 1.25-3.82, p = 0.006; HR = 2.13 CI 1.21-3.75, p = 0.009 respectively).Elevated levels of PRO-C3 and PRO-C6 associate with IPF disease progression. Collagen synthesis and degradation biomarkers have the potential to enhance clinical trials in IPF and may inform prognostic assessment and therapeutic decision making in the clinic.

The topical study of inhaled drug (salbutamol) delivery in idiopathic pulmonary fibrosis.

BACKGROUND: Our aim was to investigate total and regional lung delivery of salbutamol in subjects with idiopathic pulmonary fibrosis (IPF). METHODS: The TOPICAL study was a 4-period, partially-randomised, controlled, crossover study to investigate four aerosolised approaches in IPF subjects. Nine subjects were randomised to receive 99mTechnetium-labelled monodisperse salbutamol (1.5 µm or 6 µm; periods 1 and 2). Subjects also received radio-labelled salbutamol using a polydisperse nebuliser (period 3) and unlabelled salbutamol (400 µg) using a polydisperse pressurized metered dose inhaler with volumatic spacer (pMDI; period 4). RESULTS: Small monodisperse particles (1.5 µm) achieved significantly better total lung deposition (TLD, mean % ± SD) than larger particles (6 µm), where polydisperse nebulisation was poor; (TLD, 64.93 ± 10.72; 50.46 ± 17.04; 8.19 ± 7.72, respectively). Small monodisperse particles (1.5 µm) achieved significantly better lung penetration (mean % ± SD) than larger particles (6 µm), and polydisperse nebulisation showed lung penetration similar to the small particles; PI (mean ± SD) 0.8 ± 0.16, 0.49 ± 0.21, and 0.73 ± 0.19, respectively. Higher dose-normalised plasma salbutamol levels were observed following monodisperse 1.5 µm and 6 µm particles, compared to polydisperse pMDI inhalation, while lowest plasma levels were observed following polydisperse nebulisation. CONCLUSION: Our data is the first systematic investigation of inhaled drug delivery in fibrotic lung disease. We provide evidence that inhaled drugs can be optimised to reach the peripheral areas of the lung where active scarring occurs in IPF. TRIAL REGISTRATION: This trial was registered on clinicaltrials.gov ( NCT01457261 ).

Safety, tolerability and pharmacokinetics of GSK3008348, a novel integrin αvß6 inhibitor, in healthy participants.

PURPOSE: Inhaled drug delivery is an attractive route by which to deliver drugs to lungs of patients with idiopathic pulmonary fibrosis (IPF). GSK3008348 is a potent and selective small molecule being developed as the first inhaled inhibitor of the αvß6 integrin for the treatment of IPF. The phase 1 first-time-in-human clinical trial (NCT02612051) presented here was designed to investigate the safety, tolerability and pharmacokinetic (PK) profile of single doses of GSK3008348 in healthy participants. METHODS: Single ascending doses of GSK3008348 were administered to three cohorts of eight healthy participants in a randomised, double-blind, placebo-controlled, 4-period crossover design. Safety, tolerability and PK were assessed after single doses of 1-3000 mcg given by nebulisation. RESULTS: A total of 29 participants were enrolled and received at least one dose of study treatment. There were no serious adverse events (AE) reported in any participant. No trends or clinically important differences were noted in the incidence or intensity of AEs or other safety assessments. Maximum plasma concentrations of GSK3008348 were generally attained within approximately 30 min after start of nebulisation, with geometric mean terminal elimination half-lives ranging from 7.95 to 10.2 h. Exposures, as measured by area under the plasma concentration-time curve (AUC), were dose proportional across all doses where estimates were possible (100-3000 mcg). Dose normalised geometric mean Cmax increased with dose up to 3000 mcg. This supra proportionality was relatively modest, with a less than 3-fold increase over the range from 30 to 3000 mcg. The reason(s) for this observation are currently not known but may be due to slower absorption at the lowest doses. All exposures were within the exposure margins set by the non-clinical toxicity studies and so this is not expected to have any impact on safety. CONCLUSIONS: In summary, GSK3008348 was well tolerated at single doses up to 3000 mcg in healthy participants, and its PK profile was dose proportional at potentially clinically relevant doses (300-3000 mcg). These findings support further development of GSK3008348 as a novel inhaled treatment option for IPF.

The fibroblast hormone endotrophin is a biomarker of mortality in chronic diseases.

Fibrosis, driven by fibroblast activities, is an important contributor to morbidity and mortality in most chronic diseases. Endotrophin, a signaling molecule derived from processing of type VI collagen by highly activated fibroblasts, is involved in fibrotic tissue remodeling. Circulating levels of endotrophin have been associated with an increased risk of mortality in multiple chronic diseases. We conducted a systematic literature review collecting evidence from original papers published between 2012 and January 2023 that reported associations between circulating endotrophin (PRO-C6) and mortality. Cohorts with data available to the study authors were included in an Individual Patient Data (IPD) meta-analysis that evaluated the association of PRO-C6 with mortality (PROSPERO registration number: CRD42023340215) after adjustment for age, sex and BMI, where available. In the IPD meta-analysis including sixteen cohorts of patients with different non-communicable chronic diseases (NCCDs) (N=15,205) the estimated summary hazard ratio for 3-years all-cause mortality was 2.10 (95% CI 1.75-2.52) for a 2-fold increase in PRO-C6, with some heterogeneity observed between the studies (I2=70%). This meta-analysis is the first study documenting that fibroblast activities, as quantified by circulating endotrophin, are independently associated with mortality across a broad range of NCCDs. This indicates that, irrespective of disease, interstitial tissue remodeling, and consequently fibroblast activities, has a central role in adverse clinical outcomes, and should be considered with urgency from drug developers as a target to treat.

Association study of human leukocyte antigen variants and idiopathic pulmonary fibrosis.

Introduction: Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia marked by progressive lung fibrosis and a poor prognosis. Recent studies have highlighted the potential role of infection in the pathogenesis of IPF, and a prior association of the HLA-DQB1 gene with idiopathic fibrotic interstitial pneumonia (including IPF) has been reported. Owing to the important role that the human leukocyte antigen (HLA) region plays in the immune response, here we evaluated if HLA genetic variation was associated specifically with IPF risk. Methods: We performed a meta-analysis of associations of the HLA region with IPF risk in individuals of European ancestry from seven independent case-control studies of IPF (comprising 5159 cases and 27 459 controls, including a prior study of fibrotic interstitial pneumonia). Single nucleotide polymorphisms, classical HLA alleles and amino acids were analysed and signals meeting a region-wide association threshold of p<4.5×10-4 and a posterior probability of replication >90% were considered significant. We sought to replicate the previously reported HLA-DQB1 association in the subset of studies independent of the original report. Results: The meta-analysis of all seven studies identified four significant independent single nucleotide polymorphisms associated with IPF risk. However, none met the posterior probability for replication criterion. The HLA-DQB1 association was not replicated in the independent IPF studies. Conclusion: Variation in the HLA region was not consistently associated with risk in studies of IPF. However, this does not preclude the possibility that other genomic regions linked to the immune response may be involved in the aetiology of IPF.

Genome-wide SNP-sex interaction analysis of susceptibility to idiopathic pulmonary fibrosis.

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic lung condition that is more prevalent in males than females. The reasons for this are not fully understood, with differing environmental exposures due to historically sex-biased occupations, or diagnostic bias, being possible explanations. To date, over 20 independent genetic variants have been identified to be associated with IPF susceptibility, but these have been discovered when combining males and females. Our aim was to test for the presence of sex-specific associations with IPF susceptibility and assess whether there is a need to consider sex-specific effects when evaluating genetic risk in clinical prediction models for IPF. Methods: We performed genome-wide single nucleotide polymorphism (SNP)-by-sex interaction studies of IPF risk in six independent IPF case-control studies and combined them using inverse-variance weighted fixed effect meta-analysis. In total, 4,561 cases (1,280 females and 2,281 males) and 23,500 controls (8,360 females and 14,528 males) of European genetic ancestry were analysed. We used polygenic risk scores (PRS) to assess differences in genetic risk prediction between males and females. Findings: Three independent genetic association signals were identified. All showed a consistent direction of effect across all individual IPF studies and an opposite direction of effect in IPF susceptibility between females and males. None had been previously identified in IPF susceptibility genome-wide association studies (GWAS). The predictive accuracy of the PRSs were similar between males and females, regardless of whether using combined or sex-specific GWAS results. Interpretation: We prioritised three genetic variants whose effect on IPF risk may be modified by sex, however these require further study. We found no evidence that the predictive accuracy of common SNP-based PRSs varies significantly between males and females.

The Burden and Impact of Cough in Patients with Idiopathic Pulmonary Fibrosis: An Analysis of the Prospective Observational PROFILE Study.

Rationale: Cough is a commonly reported symptom in idiopathic pulmonary fibrosis (IPF) that negatively impacts patient-reported quality of life (QoL). However, both the burden of cough at diagnosis and the behavior of cough over time have not been systematically described in patients with IPF. Objectives: By utilizing data prospectively collected as part of the PROFILE study, we sought to assess cough burden and the impact that this has on QoL within a cohort of patients with newly diagnosed IPF. We also reexamined the previously described relationship between cough and mortality and the association of cough with the MUC5B promoter polymorphism. Methods: The PROFILE study is a multicenter, prospective, observational, longitudinal cohort study of incident IPF. Scores on the Leicester Cough Questionnaire (LCQ) were recorded at baseline in 632 subjects and then repeated 6 monthly in a subset (n = 216) of the cohort. Results: The median LCQ score at diagnosis was 16.1 (interquartile range, 6.5). LCQ scores remained stable over the subsequent year in the majority of patients. There was a weak association between LCQ score and baseline lung function, with worse cough-related QoL associated with more severe physiological impairment. Cough scores were not associated with subsequent mortality after correcting for baseline lung function. Furthermore, there was no relationship between LCQ score and MUC5B promoter polymorphism status. Conclusions: The burden of cough in IPF is high. Although cough is weakly associated with disease severity at baseline, cough-specific QoL, as measured by the LCQ, confers no prognostic value. Cough-specific QoL burden remains relatively stable over time and does not associate with MUC5B promoter polymorphism.