Phase 2, Double-Blind, Placebo-controlled Trial of a c-Jun N-Terminal Kinase Inhibitor in Idiopathic Pulmonary Fibrosis.

Rationale: Idiopathic pulmonary fibrosis is a fatal and progressive disease with limited treatment options. Objectives: We sought to assess the efficacy and safety of CC-90001, an oral inhibitor of c-Jun N-terminal kinase 1, in patients with idiopathic pulmonary fibrosis. Methods: In a Phase 2, randomized (1:1:1), double-blind, placebo-controlled study (ClinicalTrials.gov ID: NCT03142191), patients received CC-90001 (200 or 400 mg) or placebo once daily for 24 weeks. Background antifibrotic treatment (pirfenidone) was allowed. The primary endpoint was change in the percentage of predicted FVC (ppFVC) from baseline to Week 24; secondary endpoints included safety. Measurements and Main Results: In total, 112 patients received at least one dose of study drug. The study was terminated early because of a strategic decision made by the sponsor. Ninety-one patients (81%) completed the study. The least-squares mean changes from baseline in ppFVC at Week 24 were -3.1% (placebo), -2.1% (200 mg), and -1.0% (400 mg); the differences compared with placebo were 1.1% (200 mg; 95% confidence interval: -2.1, 4.3; P = 0.50) and 2.2% (400 mg; 95% confidence interval: -1.1, 5.4; P = 0.19). Adverse event frequency was similar in patients in the combined CC-90001 arms versus placebo. The most common adverse events were nausea, diarrhea, and vomiting, which were more frequent in patients in CC-90001 arms versus placebo. Fewer patients in the CC-90001 arms than in the placebo arm experienced cough and dyspnea. Conclusions: Treatment with CC-90001 over 24 weeks led to numerical improvements in ppFVC in patients with idiopathic pulmonary fibrosis compared with placebo. CC-90001 was generally well tolerated, which was consistent with previous studies. Clinical trial registered with www.clinicaltrials.gov (NCT03142191).

CC-90001, a c-Jun N-terminal kinase (JNK) inhibitor, in patients with pulmonary fibrosis: design of a phase 2, randomised, placebo-controlled trial.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a progressive and often fatal interstitial lung disease (ILD); other ILDs have a progressive, fibrotic phenotype (PF-ILD). Antifibrotic agents can slow but not stop disease progression in patients with IPF or PF-ILD. c-Jun N-terminal kinases (JNKs) are stress-activated protein kinases implicated in the underlying mechanisms of fibrosis, including epithelial cell death, inflammation and polarisation of profibrotic macrophages, fibroblast activation and collagen production. CC-90001, an orally administered (PO), one time per day, JNK inhibitor, is being evaluated in IPF and PF-ILD. METHODS AND ANALYSIS: This is a phase 2, randomised, double-blind, placebo-controlled study evaluating efficacy and safety of CC-90001 in patients with IPF (main study) and patients with PF-ILD (substudy). Both include an 8-week screening period, a 24-week treatment period, up to an 80-week active-treatment extension and a 4-week post-treatment follow-up. Patients with IPF (n=165) will be randomised 1:1:1 to receive 200 mg or 400 mg CC-90001 or placebo administered PO one time per day; up to 25 patients/arm will be permitted concomitant pirfenidone use. Forty-five patients in the PF-ILD substudy will be randomised 2:1 to receive 400 mg CC-90001 or placebo. The primary endpoint is change in per cent predicted forced vital capacity from baseline to Week 24 in patients with IPF. ETHICS AND DISSEMINATION: This study will be conducted in accordance with Good Clinical Practice guidelines, Declaration of Helsinki principles and local ethical and legal requirements. Results will be reported in a peer-reviewed publication. TRIAL REGISTRATION NUMBER: NCT03142191.

Interleukin-1beta causes acute lung injury via alphavbeta5 and alphavbeta6 integrin-dependent mechanisms.

Interleukin (IL)-1beta has previously been shown to be among the most biologically active cytokines in the lungs of patients with acute lung injury (ALI). Furthermore, there is experimental evidence that lung vascular permeability increases after short-term exposure to IL-1 protein, although the exact mechanism is unknown. Therefore, the objective of this study was to determine the mechanisms of IL-1beta-mediated increase in lung vascular permeability and pulmonary edema following transient overexpression of this cytokine in the lungs by adenoviral gene transfer. Lung vascular permeability increased with intrapulmonary IL-1beta production with a maximal effect 7 days after instillation of the adenovirus. Furthermore, inhibition of the alphavbeta6 integrin and/or transforming growth factor-beta attenuated the IL-1beta-induced ALI. The results of in vitro studies indicated that IL-1beta caused the activation of transforming growth factor-beta via RhoA/alphavbeta6 integrin-dependent mechanisms and the inhibition of the alphavbeta6 integrin and/or transforming growth factor-beta signaling completely blocked the IL-1beta-mediated protein permeability across alveolar epithelial cell monolayers. In addition, IL-1beta increased protein permeability across lung endothelial cell monolayers via RhoA- and alphavbeta5 integrin-dependent mechanisms. The final series of in vivo experiments demonstrated that pretreatment with blocking antibodies to both the alphavbeta5 and alphavbeta6 integrins had an additive protective effect against IL-1beta-induced ALI. In summary, these results demonstrate a critical role for the alphavbeta5/beta6 integrins in mediating the IL-1beta-induced ALI and indicate that these integrins could be a potentially attractive therapeutic target in ALI.

Inhibition of integrin alpha(v)beta6, an activator of latent transforming growth factor-beta, prevents radiation-induced lung fibrosis.

RATIONALE: In experimental models, lung fibrosis is dependent on transforming growth factor (TGF)-beta signaling. TGF-beta is secreted in a latent complex with its propeptide, and TGF-beta activators release TGF-beta from this complex. Because the integrin alpha(v)beta6 is a major TGF-beta activator in the lung, inhibition of alpha(v)beta6-mediated TGF-beta activation is a logical strategy to treat lung fibrosis. OBJECTIVES: To determine, by genetic and pharmacologic approaches, whether murine radiation-induced lung fibrosis is dependent on alpha(v)beta6. METHODS: Wild-type mice, alpha(v)beta6-deficient (Itgb6-/-) mice, and mice heterozygous for a Tgfb1 mutation that eliminates integrin-mediated activation (Tgfb1(+/RGE)) were exposed to 14 Gy thoracic radiation. Some mice were treated with an anti-alpha(v)beta6 monoclonal antibody or a soluble TGF-beta receptor fusion protein. Alpha(v)beta6 expression was determined by immunohistochemistry. Fibrosis, inflammation, and gene expression patterns were assessed 20-32 weeks postirradiation. MEASUREMENTS AND MAIN RESULTS: Beta6 integrin expression increased within the alveolar epithelium 18 weeks postirradiation, just before onset of fibrosis. Itgb6-/- mice were completely protected from fibrosis, but not from late radiation-induced mortality. Anti-alpha(v)beta6 therapy (1-10 mg/kg/wk) prevented fibrosis, but only higher doses (6-10 mg/kg/wk) caused lung inflammation similar to that in Itgb6-/- mice. Tgfb1-haploinsufficient mice were also protected from fibrosis. CONCLUSIONS: Alpha(v)beta6-mediated TGF-beta activation is required for radiation-induced lung fibrosis. Together with previous data, our results demonstrate a robust requirement for alpha(v)beta6 in distinct fibrosis models. Inhibition of alphavbeta6-mediated TGF-beta activation is a promising new approach for antifibrosis therapy.

Partial inhibition of integrin alpha(v)beta6 prevents pulmonary fibrosis without exacerbating inflammation.

RATIONALE: Transforming growth factor (TGF)-beta has a central role in driving many of the pathological processes that characterize pulmonary fibrosis. Inhibition of the integrin alpha(v)beta6, a key activator of TGF-beta in lung, is an attractive therapeutic strategy, as it may be possible to inhibit TGF-beta at sites of alpha(v)beta6 up-regulation without affecting other homeostatic roles of TGF-beta. OBJECTIVES: To analyze the expression of alpha(v)beta6 in human pulmonary fibrosis, and to functionally test the efficacy of therapeutic inhibition of alpha(v)beta6-mediated TGF-beta activation in murine bleomycin-induced pulmonary fibrosis. METHODS: Lung biopsies from patients with a diagnosis of systemic sclerosis or idiopathic pulmonary fibrosis were stained for alpha(v)beta6 expression. A range of concentrations of a monoclonal antibody that blocks alpha(v)beta6-mediated TGF-beta activation was evaluated in murine bleomycin-induced lung fibrosis. MEASUREMENTS AND MAIN RESULTS: Alpha(v)beta6 is overexpressed in human lung fibrosis within pneumocytes lining the alveolar ducts and alveoli. In the bleomycin model, alpha(v)beta6 antibody was effective in blocking pulmonary fibrosis. At high doses, there was increased expression of markers of inflammation and macrophage activation, consistent with the effects of TGF-beta inhibition in the lung. Low doses of antibody attenuated collagen expression without increasing alveolar inflammatory cell populations or macrophage activation markers. CONCLUSIONS: Partial inhibition of TGF-beta using alpha(v)beta6 integrin antibodies is effective in blocking murine pulmonary fibrosis without exacerbating inflammation. In addition, the elevated expression of alpha(v)beta6, an activator of the fibrogenic cytokine, TGF-beta, in human pulmonary fibrosis suggests that alpha(v)beta6 monoclonal antibodies could represent a promising new therapeutic strategy for treating pulmonary fibrosis.

Role of integrin alphav beta6 in acute lung injury induced by Pseudomonas aeruginosa.

Deletion of integrin alphav beta6 has been associated with significant protection in experiments where lung injury was induced by bleomycin, lipophilic polysaccharides, and high tidal volume ventilation. This has led to the suggestion that antibody blockade of this integrin is a novel therapy for acute lung injury. We questioned whether beta6 gene deletion would also protect against Pseudomonas aeruginosa-induced acute lung injury. Wild-type and littermate beta6-null mice, as well as recombinant soluble TGF-beta receptor type II-Fc (rsTGF-betaRII-Fc) and anti-alphav beta6 treated wild-type mice, were instilled with live P. aeruginosa. Four or 8 h after bacterial instillation, the mice were euthanized, and either bronchoalveolar lavage fluid or lung homogenates were obtained. Deletion of the beta6 gene resulted in an overall increase in inflammatory cells in the lungs. Bacterial numbers from the lung homogenates of infected beta6-null mice were significantly decreased compared to the numbers in the wild-type mice (1.6 x 10(6) CFU versus 4.2 x 10(6) CFU [P < 0.01]). There were no significant differences in P. aeruginosa-mediated increases in lung endothelial permeability between wild-type and beta6-null mice. Similarly, pretreatment with the alphav beta6 antibody or with rsTGF-betaRII-Fc did not significantly affect the P. aeruginosa-induced lung injury or rate of survival compared to pretreatment with control immunoglobulin G. We conclude that deletion or inhibition of the integrin alphav beta6 did not protect animals from P. aeruginosa-induced lung injury. However, these therapies also did not increase the lung injury, suggesting that host defense was not compromised by this promising new therapy.

Long-acting forms of Sonic hedgehog with improved pharmacokinetic and pharmacodynamic properties are efficacious in a nerve injury model.

The therapeutic effects of the Sonic hedgehog (Shh) have been difficult to evaluate because of its relatively short serum half-life. To address this issue polyethylene glycol modification (PEGylation) was investigated as an approach to improve systemic exposure. Shh was PEGylated by a targeted approach using cysteines that were engineered into the protein by site-directed mutagenesis as the sites of attachment. Sixteen different versions of the protein containing one, two, three, or four sites of attachment were characterized. Two forms were selected for extensive testing in animals, Shh A192C, which provided a single site for PEGylation, and Shh A192C/N91C, which provided two sites. The PEGylated proteins were evaluated for reaction specificity by SDS-PAGE and peptide mapping, in vitro potency, pharmacokinetic and pharmacodynamic properties, and efficacy in a sciatic nerve injury model. Targeted PEGylation was highly selective for the engineered cysteines and had no deleterious effect on Shh function in vitro. Systemic clearance values in rats decreased from 117.4 mL/h/kg for unmodified Shh to 29.4 mL/h/kg for mono-PEGylated Shh A192C that was modified with 20 kDa PEG-maleimide and to 2.5 mL/h/kg for di-PEGylated Shh A192C/N91C modified with 2, 20 kDa PEG vinylsulfone adducts. Serum half-life increased from 1 h for unmodified Shh to 7.0 and 12.6 h for the mono- and di-PEGylated products. These changes in clearance and half-life resulted in higher serum levels of Shh in the PEG-Shh-treated animals. In Ptc-LacZ knock-in mice expressing lacZ under regulation of the Shh receptor Patched, about a 10-fold lower dose of PEG-Shh was needed to induce beta-galactosidase than for the unmodified protein. Therapeutic treatment of mice with PEG-Shh enhanced the regeneration of injured sciatic nerves. These studies demonstrate that targeted PEGylation greatly alters the pharmacokinetic and pharmacodynamic properties of Shh, resulting in a form with improved pharmaceutical properties.

Mice that lack activity of alphavbeta6- and alphavbeta8-integrins reproduce the abnormalities of Tgfb1- and Tgfb3-null mice.

The arginine-glycine-aspartate (RGD)-binding integrins alphavbeta6 and alphavbeta8 activate latent TGFbeta1 and TGFbeta3 in vivo, but it is uncertain whether other RGD-binding integrins such as integrins alphavbeta5 and alphavbeta3 activate these TGFbeta isoforms. To define the combined role of alphavbeta6- and alphavbeta8-integrin in TGFbeta activation, we analyzed mice lacking function of both integrins by means of gene deletion and/or pharmacologic inhibition. Most Itgb6-/-;Itgb8-/- embryos die at mid-gestation; those that survive develop cleft palate-as observed in Tgfb3-/- mice. Itgb8-/- mice treated with an anti-alphavbeta6-integrin antibody develop severe autoimmunity and lack Langerhans cells-similar to Tgfb1-null mice. These results support a model in which TGFbeta3-mediated palate fusion and TGFbeta1-mediated suppression of autoimmunity and generation of Langerhans cells require integrins alphavbeta6 and alphavbeta8 but not other RGD-binding integrins as TGFbeta activators.

Antibody-mediated blockade of integrin alpha v beta 6 inhibits tumor progression in vivo by a transforming growth factor-beta-regulated mechanism.

The alpha(v)beta(6) integrin is up-regulated on epithelial malignancies and has been implicated in various aspects of cancer progression. Immunohistochemical analysis of alpha(v)beta(6) expression in 10 human tumor types showed increased expression relative to normal tissues. Squamous carcinomas of the cervix, skin, esophagus, and head and neck exhibited the highest frequency of expression, with positive immunostaining in 92% (n = 46), 84% (n = 49), 68% (n = 56), and 64% (n = 100) of cases, respectively. We studied the role of alpha(v)beta(6) in Detroit 562 human pharyngeal carcinoma cells in vitro and in vivo. Prominent alpha(v)beta(6) expression was detected on tumor xenografts at the tumor-stroma interface resembling the expression on human head and neck carcinomas. Nonetheless, coculturing cells in vitro with matrix proteins did not up-regulate alpha(v)beta(6) expression. Detroit 562 cells showed alpha(v)beta(6)-dependent adhesion and activation of transforming growth factor-beta (TGF-beta) that was inhibited >90% with an alpha(v)beta(6) blocking antibody, 6.3G9. Although both recombinant soluble TGF-beta receptor type-II (rsTGF-beta RII-Fc) and 6.3G9 inhibited TGF-beta-mediated Smad2/3 phosphorylation in vitro, there was no effect on proliferation. Conversely, in vivo, 6.3G9 and rsTGF-beta RII-Fc inhibited xenograft tumor growth by 50% (n = 10, P < 0.05) and >90% (n = 10, P < 0.001), respectively, suggesting a role for the microenvironment in this response. However, stromal collagen and smooth muscle actin content in xenograft sections were unchanged with treatments. Although further studies are required to consolidate in vitro and in vivo results and define the mechanisms of tumor inhibition by alpha(v)beta(6) antibodies, our findings support a role for alpha(v)beta(6) in human cancer and underscore the therapeutic potential of function blocking alpha(v)beta(6) antibodies.

Alphav beta6 integrin regulates renal fibrosis and inflammation in Alport mouse.

The transforming growth factor (TGF)-beta-inducible integrin alpha v beta6 is preferentially expressed at sites of epithelial remodeling and has been shown to bind and activate latent precursor TGF-beta. Herein, we show that alpha v beta6 is overexpressed in human kidney epithelium in membranous glomerulonephritis, diabetes mellitus, IgA nephropathy, Goodpasture's syndrome, and Alport syndrome renal epithelium. To assess the potential regulatory role of alpha v beta6 in renal disease, we studied the effects of function-blocking alpha v beta6 monoclonal antibodies (mAbs) and genetic ablation of the beta6 subunit on kidney fibrosis in Col4A3-/- mice, a mouse model of Alport syndrome. Expression of alpha v beta6 in Alport mouse kidneys was observed primarily in cortical tubular epithelial cells and in correlation with the progression of fibrosis. Treatment with alpha v beta6-blocking mAbs inhibited accumulation of activated fibroblasts and deposition of interstitial collagen matrix. Similar inhibition of renal fibrosis was observed in beta6-deficient Alport mice. Transcript profiling of kidney tissues showed that alpha v beta6-blocking mAbs significantly inhibited disease-associated changes in expression of fibrotic and inflammatory mediators. Similar patterns of transcript modulation were produced with recombinant soluble TGF-beta RII treatment, suggesting shared regulatory functions of alpha v beta6 and TGF-beta. These findings demonstrate that alpha v beta6 can contribute to the regulation of renal fibrosis and suggest this integrin as a potential therapeutic target.