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.

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.

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.

Strategies for biomarker discovery in fibrotic disease.

The discovery and development of biomarkers for fibrotic diseases have potential utility in clinical decision-making as well as in pharmaceutical research and development. This review describes strategies for identifying diagnostic, prognostic and theranostic biomarkers. A range of technologies and platforms for biomarker discovery are highlighted, including several with specific relevance for fibrosis. Some challenges specific to fibrotic diseases are outlined including; benchmarking biomarkers against imperfect clinical measures of fibrosis, the complexity resulting from diverse aetiologies and target organs, and the availability of samples (including biopsy) from well-characterised patients with fibrotic disease. To overcome these challenges collaboration amongst clinical specialities as well as between academia and industry is essential. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.

Diverse functions of clusterin promote and protect against the development of pulmonary fibrosis.

Pulmonary fibrosis is a progressive scarring disorder of the lung with dismal prognosis and no curative therapy. Clusterin, an extracellular chaperone and regulator of cell functions, is reduced in bronchoalveolar lavage fluid of patients with pulmonary fibrosis. However, its distribution and role in normal and fibrotic human lung are incompletely characterized. Immunohistochemical localization of clusterin revealed strong staining associated with fibroblasts in control lung and morphologically normal areas of fibrotic lung but weak or undetectable staining in fibrotic regions and particularly fibroblastic foci. Clusterin also co-localized with elastin in vessel walls and additionally with amorphous elastin deposits in fibrotic lung. Analysis of primary lung fibroblast isolates in vitro confirmed the down-regulation of clusterin expression in fibrotic compared with control lung fibroblasts and further demonstrated that TGF-ß1 is capable of down-regulating fibroblast clusterin expression. shRNA-mediated down-regulation of clusterin did not affect TGF-ß1-induced fibroblast-myofibroblast differentiation but inhibited fibroblast proliferative responses and sensitized to apoptosis. Down-regulation of clusterin in fibrotic lung fibroblasts at least partly due to increased TGF-ß1 may therefore represent an appropriate but insufficient response to limit fibroproliferation. Reduced expression of clusterin in the lung may also limit its extracellular chaperoning activity contributing to dysregulated deposition of extracellular matrix proteins.

An epithelial biomarker signature for idiopathic pulmonary fibrosis: an analysis from the multicentre PROFILE cohort study.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disorder with a variable disease trajectory. The aim of this study was to assess potential biomarkers to predict outcomes for people with IPF. METHODS: PROFILE is a large prospective longitudinal cohort of treatment-naive patients with IPF. We adopted a two-stage discovery and validation design using patients from the PROFILE cohort. For the discovery analysis, we examined 106 patients and 50 age and sex matched healthy controls from Nottingham University Hospitals NHS Trust and the Royal Brompton Hospital. We did an unbiased, multiplex immunoassay assessment of 123 biomarkers. We further investigated promising novel markers by immunohistochemical assessment of IPF lung tissue. In the validation analysis, we examined samples from 206 people with IPF from among the remaining 212 patients recruited to PROFILE Central England. We used the samples to attempt to replicate the biomarkers identified from the discovery analysis by use of independent immunoassays for each biomarker. We investigated the predictive power of the selected biomarkers to identify individuals with IPF who were at risk of progression or death. The PROFILE studies are registered on ClinicalTrials.gov, numbers NCT01134822 (PROFILE Central England) and NCT01110694 (PROFILE Royal Brompton Hospital). FINDINGS: In the discovery analysis, we identified four serum biomarkers (surfactant protein D, matrix metalloproteinase 7, CA19-9, and CA-125) that were suitable for replication. Histological assessment of CA19-9 and CA-125 suggested that these proteins were markers of epithelial damage. Replication analysis showed that baseline values of surfactant protein D (46·6 ng/mL vs 34·6 ng/mL, p=0·0018) and CA19-9 (53·7 U/mL vs 22·2 U/mL; p<0·0001) were significantly higher in patients with progressive disease than in patients with stable disease, and rising concentrations of CA-125 over 3 months were associated with increased risk of mortality (HR 2·542, 95% CI 1·493-4·328, p=0·00059). INTERPRETATION: We have identified serum proteins secreted from metaplastic epithelium that can be used to predict disease progression and death in IPF. FUNDING: GlaxoSmithKline R&D and the UK Medical Research Council.

Longitudinal change in collagen degradation biomarkers in idiopathic pulmonary fibrosis: an analysis from the prospective, multicentre PROFILE study.

BACKGROUND: Idiopathic pulmonary fibrosis, a progressive and inevitably fatal disorder, has a highly variable clinical course. Biomarkers that reflect disease activity are urgently needed to inform patient management and for use as biomarkers of therapeutic response (theragnostic biomarkers) in clinical trials. We aimed to determine whether dynamic change in markers of extracellular matrix (ECM) turnover predicts progression of idiopathic pulmonary fibrosis as determined by change in forced vital capacity and death. METHODS: In this ongoing prospective, multicentre, observational cohort study (PROFILE), participants with idiopathic pulmonary fibrosis or idiopathic non-specific interstitial pneumonia diagnosed within the preceding 6 months were recruited from two coordinating centres (Nottingham, UK, and, Royal Brompton Hospital, London, UK). Serum samples were prospectively collected at baseline, 1 month, 3 months, and 6 months and were analysed for a panel of novel matrix metalloprotease (MMP)-degraded ECM proteins, by ELISA-based, neoepitope assay. 11 neoepitopes were tested in a discovery cohort of 55 patients to identify biomarkers of sufficient rigour for more detailed analyses. Eight were then further assessed in a validation cohort of 134 patients with 50 age-matched and sex-matched controls. Changes in biomarker concentrations were related to subsequent progression of idiopathic pulmonary fibrosis (defined as death or decline in forced vital capacity >10% at 12 months after study enrolment) using a repeated measures model. The PROFILE study is registered on ClinicalTrials.gov, numbers NCT01134822 and NCT01110694. FINDINGS: Of 214 eligible participants recruited between Sept 1, 2010, and March 31, 2012, 189 had a confirmed diagnosis of idiopathic pulmonary fibrosis and were included in subsequent analyses. In the discovery cohort, mean concentrations of seven neoepitopes (BGM, p=0·009; C1M, p=0·009; C3M, p=0·046; C6M, p=0·032; CRPM, p=0·008; ELM2, p=0·02; and VICM, p=0·0007) differed significantly between healthy controls and participants with idiopathic pulmonary fibrosis. Baseline concentrations of six neoepitopes (C1M, p=0·012; C3A, p=0·012; C3M, p=0·0005; C6M, p=0·0003; CRPM, p=0·021; and VICM, p=0·046) were significantly higher in patients with progressive idiopathic pulmonary fibrosis (n=32) than in those with stable disease (n=23). In the validation cohort, mean concentrations of C1M (p=0·001), C3M (p=0·044), C6M (p=0·003), and CRPM (p=0·024) at baseline were higher in patients with idiopathic pulmonary fibrosis than in healthy controls. When assessed longitudinally, concentrations of six neoepitopes (BGM, C1M, C3A, C3M, C6M, and CRPM) were significantly higher in patients with progressive idiopathic pulmonary fibrosis (n=71) than in patients with stable idiopathic pulmonary fibrosis (n=60) by 6 months. Baseline concentrations of two neoepitopes were associated with increased mortality (C1M: HR 1·62 [95% CI 1·14-2·31], p=0·0069; C3A: 1·91 [1·06-3·46], p=0·032). The rate of change between baseline and 3 months of six neoepitopes (BGM: HR 1·084 [95% CI 1·03-1·14], p=0·0019; C1M: 1·01 [1·003-1·017], p=0·0039; C3M: 1·106 [1·045-1·170], p=0·0005; C5M: 1·003 [1·001-1·005], p=0·0011; C6M: 1·042 [1·007-1·078], p=0·017; and CRPM: 1·38 [1·16-1·63], p=0·0002) was strongly predictive of overall survival, and the increased risk was proportional to the magnitude of change in neoepitope concentrations. The strongest association with 3-month rate of biomarker change was recorded for CRPM; greater than 0 ng/mL per month conferred a HR of 2·16 (95% CI 1·15-4·07), whereas a rate greater than 1 ng/mL per month resulted in an HR 4·08 (2·14-7·8), and a rate greater than 1·7 ng/mL per month was associated with an HR 6·61 (2·74-15·94). INTERPRETATION: Concentrations of protein fragments generated by MMP activity are increased in the serum of individuals with idiopathic pulmonary fibrosis compared with healthy controls. Increased neoepitope concentrations were associated with disease progression, and the rate of this increase predicted survival. Serial measurements of neoepitopes have potential to be used as theragnostic biomarkers in clinical trials and to guide management of idiopathic pulmonary fibrosis. FUNDING: GlaxoSmithKline R&D and the Medical Research Council.