Effect of Dupilumab on Type 2 Biomarkers in Chronic Rhinosinusitis With Nasal Polyps: SINUS-52 Study Results

OBJECTIVES

Chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and non-steroidal anti-inflammatory drug-exacerbated respiratory disease (NSAID-ERD) are frequent coexisting conditions and share type 2 inflammatory pathophysiology, with interleukin (IL)-4 and IL-13 as key cytokines. Dupilumab is a monoclonal antibody that blocks the shared receptor for IL-4 and IL-13. The objective of this analysis was to evaluate dupilumab's effect on type 2 inflammation biomarkers in patients with CRSwNP with/without coexisting asthma or NSAID-ERD from the SINUS-52 (NCT02898454) study.

METHODS

Patients received treatment with dupilumab or placebo for 52 weeks. Blood and urinary biomarkers were evaluated through 52 weeks, and nasal secretions and mucosa brushings through 24 weeks.

RESULTS

Of 447 patients, 60% had coexisting asthma and 27% had coexisting NSAID-ERD. At baseline, blood eotaxin-3, eosinophils, and periostin, nasal secretion eotaxin-3, and urinary leukotriene E4 were significantly higher in patients with coexisting NSAID-ERD than without. Dupilumab reduced eotaxin-3, thymus and activation-regulated chemokine, periostin, and total immunoglobulin E in blood, eotaxin-3, periostin, IL-5, and eosinophil cationic protein in nasal secretions, and leukotriene E4 in urine. Reductions were generally similar or greater in the subgroups with asthma and NSAID-ERD than without. Dupilumab also reduced MUC5AC and mast cell counts in nasal mucosa brushings.

CONCLUSION

Dupilumab reduced local and systemic type 2 inflammatory biomarkers in patients with CRSwNP, including mast cells in nasal mucosa and cysteinyl leukotrienes in urine. These findings provide insight into the processes driving CRSwNP and the mechanisms of dupilumab's therapeutic effects.

CLINICAL TRIAL REGISTRY NAME

SINUS-52 https://www.clinicaltrials.gov/ct2/show/NCT02898454.

CLINICALTRIALS.GOV IDENTIFIER

NCT02898454.

Investigation of new biomarkers of kidney injury in renal transplant recipients undergoing graft biopsy

AIM

Urinary and blood kidney biomarkers (BM) remain insufficient for early kidney injury detection. We aimed to compare new kidney BM with histopathological data in kidney allograft recipients.

METHODS

Blood and urine samples were collected from consecutive adult patients just before graft biopsy. All kidney samples were classified according to the Banff 2007 classification. The diagnostic performance of 16 new BM was compared to those of urinary proteins, blood urea nitrogen, eGFR, and serum creatinine to identify histopathological groups.

RESULTS

Two hundred and twenty-three patients were analyzed. Microalbuminuria and urinary proteins performed well to discriminate glomerular injury from slightly modified renal parenchyma (SMRP). Urinary neutrophil gelatinase-associated lipocalin (NGAL) had the best performance relative to SMRP (AUROC .93) for acute tubular necrosis (ATN) diagnosis. Other BM had a slightly lower AUROC (.89). For the comparison of ATN to acute rejection, several new urinary BM (NGAL, cystatin C, MCP1) and classical BM (eGFR, serum creatinine) gave similar AUROC values (from .80 to .85). Urinary NGAL values in patients with ATN were 10-time higher than those with acute rejection (P=.0004).

CONCLUSION

The new BM did not outperform classical BM in the context of renal transplantation. Urinary NGAL may be useful for distinguishing between ATN and acute rejection.

Translational engagement of lysophosphatidic acid receptor 1 in skin fibrosis: from dermal fibroblasts of patients with scleroderma to tight skin 1 mouse

Background and Purpose

Genetic deletion and pharmacological studies suggest a role for lysophosphatidic acid (LPA₁) receptor in fibrosis. We investigated the therapeutic potential in systemic sclerosis (SSc) of a new orally active selective LPA₁ receptor antagonist using dermal fibroblasts from patients and an animal model of skin fibrosis.

Experimental Approach

Dermal fibroblast and skin biopsies from systemic sclerosis patients were used. Myofibroblast differentiation, gene expression and cytokine secretion were measured following LPA and/or SAR100842 treatment. Pharmacolgical effect of SAR100842 was assessed in the tight skin 1 (Tsk1) mouse model.

Key Results

SAR100842 is equipotent against various LPA isoforms. Dermal fibroblasts and skin biopsies from patients with systemic sclerosis expressed high levels of LPA₁ receptor. The LPA functional response (Ca²⁺) in systemic sclerosis dermal fibroblasts was fully antagonized with SAR100842. LPA induced myofibroblast differentiation in systemic sclerosis dermal and idiopathic pulmonary fibrosis lung fibroblasts and the secretion of inflammatory markers and activated Wnt markers. Results from systemic sclerosis dermal fibroblasts mirror those obtained in a mouse Tsk1 model of skin fibrosis. Using a therapeutic protocol, SAR100842 consistently reversed dermal thickening, inhibited myofibroblast differentiation and reduced skin collagen content. Inflammatory and Wnt pathway markers were also inhibited by SAR100842 in the skin of Tsk1 mice.

Conclusion and Implications

The effects of SAR100842 on LPA‐induced inflammation and on mechanisms linked to fibrosis like myofibroblast differentiation and Wnt pathway activation indicate that LPA₁ receptor activation plays a key role in skin fibrosis. Our results support the therapeutic potential of LPA₁ receptor antagonists in systemic sclerosis.

Efficacy of dupilumab on clinical outcomes in patients with asthma and perennial allergic rhinitis

BACKGROUND

Comorbid perennial allergic rhinitis (PAR) or year-round aeroallergen sensitivity substantially contributes to disease burden in patients with asthma. Dupilumab blocks the shared receptor for interleukin (IL) 4 and IL-13, key drivers of type 2 inflammation that play important roles in asthma and PAR. In the LIBERTY ASTHMA QUEST trial (NCT02414854), dupilumab reduced severe asthma exacerbations and improved forced expiratory volume in 1 second (FEV₁) in patients with uncontrolled, moderate-to-severe asthma, with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers at baseline (blood eosinophils and fractional exhaled nitric oxide).

OBJECTIVE

To assess dupilumab efficacy in LIBERTY ASTHMA QUEST patients with comorbid PAR.

METHODS

Severe asthma exacerbation rates, FEV₁, asthma control (5-item Asthma Control Questionnaire), rhinoconjunctivitis-specific health-related quality of life (Standardized Rhinoconjunctivitis Quality of Life Questionnaire +12 scores), and type 2 inflammatory biomarkers during the 52-week treatment period were assessed.

RESULTS

A total of 814 of the 1902 patients (42.8%) had comorbid PAR (defined as an allergic rhinitis history and ≥1 perennial aeroallergen specific immunoglobulin E (IgE) level ≥0.35 kU/L at baseline). Dupilumab, 200 and 300 mg every 2 weeks, vs placebo reduced severe exacerbations rates by 32.2% and 34.6% (P < .05 for both) and improved FEV₁ at week 12 by 0.14 L and 0.18 L (P < .01 for both); greater efficacy was observed in patients with elevated baseline blood eosinophil counts (≥300 cells/μL) and fractional exhaled nitric oxide. Dupilumab treatment also numerically improved the 5-item Asthma Control Questionnaire and Standardized Rhinoconjunctivitis Quality of Life Questionnaire +12 scores and suppressed type 2 inflammatory biomarkers.

CONCLUSION

Dupilumab improved key asthma-related outcomes, asthma control, and rhinoconjunctivitis-specific health-related quality of life while suppressing type 2 inflammatory biomarkers and perennial allergen-specific IgE in patients with moderate-to-severe asthma and comorbid PAR, highlighting its dual inhibitory effects on IL-4 and IL-13 and its role in managing asthma and PAR.

Idiopathic Pulmonary Fibrosis: Prospective, Case-Controlled Study of Natural History and Circulating Biomarkers

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with 3 to 5 years' survival. Although FVC is used to assess disease progression and treatment response, identifying predictive circulating blood biomarkers could help identify specific biologic pathways for treatment. An international, prospective, noninterventional, case-controlled, 52-week study was therefore conducted to identify a clinical and biomarker baseline profile predictive of longitudinal disease behavior.

METHODS

Patients with IPF and control subjects had lung function tests and blood sampling for biomarker quantification (control subjects at baseline only). The primary end point was disease progression rate (composite end point: decrease ≥ 10% from baseline in FVC % predicted, decrease ≥ 15% from baseline in diffusing capacity of the lung for carbon monoxide % predicted, lung transplantation, death) at week 52 and its relationship to selected biomarkers at baseline.

RESULTS

Altogether, 211 subjects (154 patients with IPF and 57 control subjects) were enrolled; one-third of patients (n = 47) with IPF had progressed by week 52. Biomarkers CC-chemokine ligand 18 (CCL18), intercellular adhesion molecule 1, Krebs von den Lungen-6, surfactant protein (SP)-A, SP-D, matrix metallopeptidase 7, urokinase-type plasminogen activator receptor, and two novel biomarkers, human epididymis protein-4 (HE4) and prostasin, discriminated patients with IPF vs control subjects. There was no difference in baseline CCL18 concentration between progressors and nonprogressors at week 52 (area under the receiver operating characteristic curve, 0.62; corrected P = .161). No biomarkers were predictive for disease progression.

CONCLUSIONS

Several biomarkers, including CCL18, were associated with IPF, but none predicted disease progression. Two novel biomarkers, HE4 and prostasin, were identified and warrant further investigation.

Dupilumab Efficacy in Patients with Uncontrolled, Moderate-to-Severe Allergic Asthma

BACKGROUND

Dupilumab blocks the shared receptor component for IL-4 and IL-13, key drivers of type 2 inflammation, including IgE-mediated allergic inflammation in asthma. In the LIBERTY ASTHMA QUEST (NCT02414854) study, dupilumab reduced severe asthma exacerbations and improved forced expiratory volume in 1 second (FEV₁) in patients with uncontrolled, moderate-to-severe asthma with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers (blood eosinophils and fractional exhaled nitric oxide) at baseline.

OBJECTIVE

We assessed dupilumab's effect on key asthma outcomes in QUEST patients with/without evidence of allergic asthma (total serum IgE ≥30 IU/mL and ≥1 perennial aeroallergen-specific IgE ≥0.35 kU/L at baseline).

METHODS

Severe exacerbation rates and change from baseline in FEV₁, asthma control, and markers of type 2 inflammation during the 52-week treatment period were assessed.

RESULTS

In the allergic asthma subgroup (n = 1083), dupilumab 200/300 mg every 2 weeks versus placebo reduced severe asthma exacerbation rates (-36.9%/-45.5%; both P < .01), improved FEV₁ at week 12 (0.13 L/0.16 L; both P < .001; improvements were evident by the first evaluation at week 2) with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers at baseline, and improved asthma control. Dupilumab treatment also resulted in rapid and sustained reductions in type 2 inflammatory biomarkers. Comparable results were observed in patients without evidence of allergic asthma (n = 819).

CONCLUSION

Dupilumab reduced severe exacerbation rates, improved FEV₁ and asthma control, and suppressed type 2 inflammatory biomarkers in patients with uncontrolled, moderate-to-severe asthma with or without evidence of allergic asthma, highlighting the key role of IL-4 and IL-13 in airway inflammation.

Dupilumab Efficacy in Uncontrolled, Moderate-to-Severe Asthma with Self-Reported Chronic Rhinosinusitis

BACKGROUND

Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for IL-4 and IL-13 signaling, key drivers of type 2 inflammation. In the phase 3 study (NCT02414854), add-on dupilumab 200 mg/300 mg every 2 weeks, versus placebo, significantly reduced severe asthma exacerbations and improved pre-bronchodilator forced expiratory volume in 1 second (FEV₁) and quality-of-life measures in patients with uncontrolled, moderate-to-severe asthma, with greater efficacy observed in those with a high baseline type 2 phenotype.

OBJECTIVE

To assess the efficacy and safety of dupilumab in patients with uncontrolled, moderate-to-severe asthma with or without self-reported comorbid chronic rhinosinusitis (CRS or non-CRS).

METHODS

Comorbid CRS was self-reported by patients using an e-diary. Annualized severe exacerbation rates, changes from baseline in pre- and post-bronchodilator FEV₁, patient-reported outcomes, type 2 biomarkers, and safety were assessed.

RESULTS

CRS was self-reported by 382 of 1902 (20.1%) patients. Dupilumab 200 mg/300 mg reduced annualized severe exacerbation rates by 63%/61%, respectively, in patients with CRS, and by 42%/40% in patients without CRS (all P < .001 vs placebo). Dupilumab also improved lung function and patient-reported asthma control and quality of life, and suppressed type 2 biomarkers versus placebo in both subgroups. Clinical responses were rapid, with near-maximal responses observed at the earliest measured time points and sustained at week 52. Improvements observed in the CRS subgroup were similar to or numerically greater than those in the non-CRS subgroup.

CONCLUSION

Dupilumab showed efficacy and was generally well tolerated in patients with uncontrolled, moderate-to-severe asthma with or without CRS.

Human thrombopoietin structure-function relationships: identification of functionally important residues

Thrombopoietin (TPO) is a haematopoietic growth factor responsible for megakaryocyte progenitor proliferation and differentiation. It belongs to the four-helix-bundle cytokine family and exerts its biological effects through binding to a specific receptor, c-Mpl. With the use of site-directed mutagenesis we have generated 20 TPO mutants. Each of the TPO mutants was produced in a eukaryotic expression system and the mutants' ability to induce the proliferation of factor-dependent c-Mpl-expressing megakaryoblastic M-O7e cells was compared with that of wild-type TPO. Among the mutations studied, 10 lead to a significant decrease in TPO bioactivity. Of these ten residues, three are located in helix A of the protein (Arg10, Lys14 and Arg17) and four in helix D (His133, Gln132, Lys138 and Phe141), indicating that in TPO, as in other cytokines, these two helices are important for functional cytokine/receptor interactions. Surprisingly, mutant Arg10-->Ala (R10A) lacked any proliferative activity, despite the fact that this mutation was recently reported to have no effect on TPO/c-Mpl binding in a TPO phage ELISA [Pearce, Potts, Presta, Bald, Fendly and Wells (1997) J. Biol. Chem. 272, 20595-20602]. The lack of M-O7e proliferation is probably due to an inability of R10A mutant to promote receptor dimerization and thus receptor activation. Moreover we found that the Arg10 and Arg17 residues of TPO seem to be specific determinants for TPO/c-Mpl recognition. We also demonstrate that the O-glycosylation site located at position 110 of TPO is not necessary for the bioactivity of the cytokine.

Binding sites and transduction process of the cholecystokininB receptor: involvement of highly conserved aromatic residues of the transmembrane domains evidenced by site-directed mutagenesis

The functional significance of the extracellular amino-terminal region and of three highly conserved aromatic residues present in the fifth (TM-V) and sixth (TM-VI) transmembrane domains of the rat cholecystokinin (CCK)B receptor, transfected in Cos-7 cells, was investigated by site-directed mutagenesis. The amino-terminal region of the CCKB receptor seemed to be weakly involved in CCK binding in that the affinities of CCK8 and selective agonists and antagonists were not modified by truncation of this region. Substitution of Phe347 in TM-VI with alanine produced a mutant receptor that displays the same affinity and selectivity as the wild-type receptor for agonists, but a slightly increased affinity for the selective CCKB antagonist L-365,260. However, the addition of saturating CCK8 concentrations to cells expressing this mutant did not result in the production of inositol phosphates, demonstrating the critical role of Phe347 in CCKB receptor to G protein coupling. Substitution of Phe227 with alanine was without effect on the affinities of CCKB ligands and on phosphoinositide turnover but modified the affinity of the CCKA antagonist L-364,718. Residue Trp351 located within the CCKB receptor TM-VI is involved in the binding of CCK8 and CCK4 and of the CCK4-based antagonist PD-134,308, as illustrated by the decreased affinities of these ligands in W351A mutant. The lower affinity for CCK8 observed with this mutated CCKB receptor accounts for the higher EC50 value for phosphotidylinositol hydrolysis. This study suggests that at least part of the binding site for the agonist is located inside the transmembrane domain of the CCKB receptor, partially overlapping that of antagonists, and gives new insights into the regions involved in the transduction process.

His381 of the rat CCKB receptor is essential for CCKB versus CCKA receptor antagonist selectivity

A great interest is devoted to antagonists of the cholecystokinin type B (CCKB) receptor such as L-365,260, which reduces panic attacks in humans and to antagonists of the cholecystokinin type A (CCKA) receptor, such as L-364,718 which might be efficient in mental diseases. The A/B specificity of these antagonists was proposed to be mainly dependent on the amino acid sequence of the seventh transmembrane domain (Mantamadiotis and Baldwin (1994) Biochem. Biophys. Res. Commun. 201,1382). In our study, one of these residues, His381 was replaced in the rat CCKB receptor by leucine (the corresponding residue in the CCKA receptor), phenylalanine or arginine using site-directed mutagenesis. Changing histidine for leucine or phenylalanine did not modify significantly the affinity of the CCKB receptor antagonists, L-365,260 and PD-134,308 although both compounds belong to different chemical classes, but strongly improved the affinity of the CCKA receptor antagonists tested. Interestingly, the A selectivity of these CCKA receptor antagonists was recovered by substituting His381 by arginine. Moreover, these results are discussed on the basis of a three dimentional model of the CCKB receptor. The mutated receptors possessed unchanged binding properties for agonists, suggesting that determinants confering specificity for agonists and antagonists are different.

Mutation of Asp100 in the second transmembrane domain of the cholecystokinin B receptor increases antagonist binding and reduces signal transduction

We examined the functional significance of two residues present in the second (Asp100) and seventh (Asn391) transmembrane domains of the rat cholecystokininB (CCKB) receptor that are highly conserved among the members of the G protein-coupled receptor family. Substitution of Asn for Asp100 by using site-directed mutagenesis did not change the affinity and selectivity for agonists but slightly increased the affinity of three CCKB-selective antagonists of different chemical structures. Cells expressing the mutant receptor exhibited a 50% reduction in CCKB-induced phosphoinositide turnover compared with cells expressing the wild-type receptor, suggesting a critical role for this residue in the coupling of the CCKB receptor to G protein. This latter was shown to be insensitive to pertussis toxin treatment and could therefore belong to the Gq family. Replacement of Asn391 by Asp located in the seventh transmembrane domain did not change agonist binding or phosphoinositide turnover. This suggests that in contrast to the gonadotropin-releasing hormone receptor, there is no direct interaction in the CCKB receptor between Asp100 and Asn391. However, a rhodopsin-based molecular modeling of the CCKB receptor showed a spatial proximity between Asp100 and the carboxyl terminal part of the third intracellular loop, known to interact with G protein. This could explain the reduction in phosphoinositide turnover observed with the Asn100 mutant.

Identification and characterization of various cholecystokinin B receptor mRNA forms in rat brain tissue and partial determination of the cholecystokinin B receptor gene structure

Using the powerful method of DNA amplification, we have been able to isolate several cholecystokinin B (CCKB) receptor (CCKB-R) mRNA forms from rat brain tissue, allowing the detection of a truncated mRNA species and the determination of the CCKB-R gene structure. Unspliced precursor mRNA and the mature form were identified in the cerebral cortex, hypothalamus, and hippocampus in apparently differing proportions according to the region examined, suggesting that the expression of the CCKB-R could be modulated at a posttranscriptional level. In the case of the cerebellum, only a completely unspliced mRNA form was detected, in agreement with previous studies in which CCKB ligand binding sites were not observed. In contrast, a truncated CCKB-R mRNA, lacking 250 bp, was detected in all the studied brain regions except for the cerebellum. This mRNA, for which a cellular function has not been assigned, potentially encodes a protein consisting of 168 amino acids.