Contribution of the factors to EuroQol 5 Dimensions in rheumatoid arthritis patients achieving low disease activity/remission with abatacept treatment: post-hoc subgroup analyses of the Japanese real-world observational "ORIGAMI" study.

OBJECTIVES: To address improvements in quality of life (QOL), we analysed the relative contributions of factors to EuroQol 5 Dimensions (EQ-5D) in abatacept-treated rheumatoid arthritis (RA) patients in the ORIGAMI study. METHODS: Patients who were evaluable for disease activity through to Week 52 in the ORIGAMI study were divided into those achieving Simplified Disease Activity Index-remission/low disease activity (remission/LDA; n=178) and patients with moderate/high disease activity (MDA/HDA; n=99). We compared the changes in EQ-5D and other outcomes through to Week 52. Focusing on the remission/LDA group, the contribution of each factor to the variance of EQ-5D at baseline and Week 52 was examined using analysis of variance. RESULTS: The remission/LDA group showed greater improvements than the MDA/HDA group in EQ-5D, Japanese Health Assessment Questionnaire, visual analogue scale for pain (Pain VAS), and patient global assessment (PtGA). In the remission/LDA group, factors significantly contributing to EQ-5D were sex, C-reactive protein, and Pain VAS at baseline, and PtGA and age at Week 52. CONCLUSIONS: In RA patients who achieved remission/LDA during abatacept treatment, PtGA and age at Week 52 contribute to the variance of EQ-5D, suggesting that identification of factors associated with PtGA may be important to address improvements of QOL.

Influence of concomitant methotrexate use on the clinical effectiveness, retention, and safety of abatacept in biologic-naïve patients with rheumatoid arthritis: Post-hoc subgroup analysis of the ORIGAMI study.

OBJECTIVES: We performed post-hoc analyses of the ORIGAMI study to investigate whether concomitant methotrexate (MTX) influences the clinical outcomes of abatacept in biologic-naïve patients with rheumatoid arthritis. METHODS: Enrolled patients (n = 325) were divided into two groups according to whether abatacept was prescribed without (MTX-) or with (MTX+) concomitant MTX. We compared the changes in Simplified Disease Activity Index (SDAI), Disease Activity Score-28 with C-reactive protein (DAS28-CRP), and Japanese Health Assessment Questionnaire (J-HAQ) through to 52 weeks of treatment, the abatacept retention rate, and safety. RESULTS: At Week 52, the mean SDAI (8.9 vs. 8.8), DAS28-CRP (2.6 vs. 2.6), and J-HAQ (0.92 vs. 0.91) scores were comparable in the MTX- (n = 129) and MTX+ (n = 150) groups. Multivariable logistic regression revealed no significant association between MTX use and SDAI (low disease activity) or J-HAQ (minimum clinically important difference). The abatacept retention rates, estimated using the Kaplan-Meier method, were 73.2% and 66.7% in the MTX- and MTX+ groups, respectively. Adverse events occurred in 47.5% (of 139) and 52.2% (of 159) of patients in the MTX- and MTX+ groups, respectively. CONCLUSION: The effectiveness and safety of abatacept appeared comparable with or without concomitant MTX in this real-world clinical setting.

Increased expression of CysLT2 receptors in the lung of asthmatic mice and role in allergic responses.

Compared with CysLT1 receptors, the functional role of CysLT2 receptors in asthma has not been clarified. The purpose of this study was to determine 1) whether CysLT2 receptors are expressed in the lung of mice and if expression increases in asthmatic mice, and 2) whether CysLT2 receptors are involved in allergic leukocyte infiltration into the lung and in the development of airway remodeling in asthmatic mice. BALB/c mice were sensitized with ovalbumin (OVA) + Al(OH)3, and intratracheally challenged with OVA 4 times. Lung tissue was isolated before and after the 4th OVA challenge for detection of CysLT2 receptors by immunohistochemistry and flow cytometry. The effect of a CysLT2 receptor antagonist BayCysLT2RA on multiple antigen challenge-induced leukocyte infiltration into the lung and the development of airway remodeling was evaluated. Even in non-challenged mice, CysLT2 receptors were expressed in bronchial smooth muscle. After multiple challenges, expression was also observed in leukocytes infiltrating into alveolar spaces. CysLT2R+ leukocytes included alveolar macrophages, conventional dendritic cells, and eosinophils. BayCysLT2RA significantly inhibited multiple antigen challenge-induced increases in eosinophils and mononuclear cells in the lung. The development of airway remodeling was tended to be suppressed by CysLT2 receptor antagonist. In conclusion, CysLT2 receptors were constitutively expressed in the lung, and expression was strengthened in asthmatic mice. Activation of CysLT2 receptors was functionally involved in allergic leukocyte infiltration into the lung. The CysLT2 receptor can be a molecular target for the development of new pharmacotherapies for asthma.

A new CysLT1 and CysLT2 receptors-mediated anaphylaxis guinea pig model.

Although the effectiveness of CysLT1 receptor antagonists on asthma has been clinically established, the effects of CysLT2 receptor antagonists are still unclear. The purpose of this study was to develop a new CysLT1 and CysLT2 receptors-mediated anaphylaxis guinea pig model using S-hexyl GSH, a γ-glutamyl transpeptidase (GTP) inhibitor, to suppress conversion of LTC4 to LTD4. Actively sensitized guinea pigs were challenged with OVA in the absence or presence of S-hexyl GSH, and survival rate following anaphylactic response was monitored. OVA-induced fatal anaphylaxis in the absence of S-hexyl GSH was almost completely inhibited by montelukast, a CysLT1 receptor antagonist, but not by the CysLT2 receptor antagonist BayCysLT2RA. However, under treatment with S-hexyl-GSH, the inhibitory effect of motelukast was dramatically diminished, whereas that of BayCysLT2RA was markedly increased. The dual CysLT1/2 receptor antagonist ONO-6950 effectively inhibited anaphylactic response in both S-hexyl GSH-treated and non-treated animals. LC/MS/MS analysis revealed that S-hexyl GSH treatment actually inhibited LTC4 metabolism in the blood and lung tissues. Using S-hexyl GSH, we developed a novel CysLT1 and CysLT2 receptors-mediated anaphylaxis guinea pig model that can be useful for not only screening both CysLT2 and CysLT1/2 receptors antagonists, but also for functional analysis of CysLT2 receptors.

CysLT2 receptor activation is involved in LTC4-induced lung air-trapping in guinea pigs.

CysLT1 receptors are known to be involved in the pathogenesis of asthma. However, the functional roles of CysLT2 receptors in this condition have not been determined. The purpose of this study is to develop an experimental model of CysLT2 receptor-mediated LTC4-induced lung air-trapping in guinea pigs and use this model to clarify the mechanism underlying response to such trapping. Because LTC4 is rapidly converted to LTD4 by γ-glutamyltranspeptidase (γ-GTP) under physiological conditions, S-hexyl GSH was used as a γ-GTP inhibitor. In anesthetized artificially ventilated guinea pigs with no S-hexyl GSH treatment, i.v. LTC4-induced bronchoconstriction was almost completely inhibited by montelukast, a CysLT1 receptor antagonist, but not by BayCysLT2RA, a CysLT2 receptor antagonist. The inhibitory effect of montelukast was diminished by treatment with S-hexyl GSH, whereas the effect of BayCysLT2RA was enhanced with increasing dose of S-hexyl GSH. Macroscopic and histological examination of lung tissue isolated from LTC4-/S-hexyl-GSH-treated guinea pigs revealed air-trapping expansion, particularly at the alveolar site. Inhaled LTC4 in conscious guinea pigs treated with S-hexyl GSH increased both airway resistance and airway hyperinflation. On the other hand, LTC4-induced air-trapping was only partially suppressed by treatment with the bronchodilator salmeterol. Although montelukast inhibition of LTC4-induced air-trapping was weak, treatment with BayCysLT2RA resulted in complete suppression of this air-trapping. Furthermore, BayCysLT2RA completely suppressed LTC4-induced airway vascular hyperpermeability. In conclusion, we found in this study that CysLT2 receptors mediate LTC4-induced bronchoconstriction and air-trapping in S-hexyl GSH-treated guinea pigs. It is therefore believed that CysLT2 receptors contribute to asthmatic response involving air-trapping.

Expression of CysLT2 receptors in asthma lung, and their possible role in bronchoconstriction.

BACKGROUND: The expression and functional role of CysLT2 receptors in asthma have not been clarified. In this study, we evaluated CysLT2 receptors expression, and effects of CysLT2-and CysLT1/2-receptor antagonists on antigen-induced bronchoconstriction using isolated lung tissues from both asthma and non-asthma subjects. METHODS: CysLT1 and CysLT2 receptors expression in asthma and non-asthma lung tissue preparations was examined in immunohistochemistry experiments, and their functional roles in antigen-induced bronchoconstriction were assessed using ONO-6950, a dual CysLT1/2-receptor antagonist, montelukast, a CysLT1 receptor antagonist, and BayCysLT2RA, a CysLT2 receptor-specific antagonist. RESULTS: CysLT1 receptors were expressed on the bronchial smooth muscle and epithelium, and on alveolar leukocytes in 5 in 5 non-asthma subjects and 2 in 2 asthma subjects. On the other hand, although degrees of CysLT2 receptors expression were variable among the 5 non-asthma subjects, the expression in the asthma lung was detected on bronchial smooth muscle, epithelium and alveolar leukocytes in 2 in 2 asthma subjects. In the non-asthma specimens, antagonism of CysLT2 receptors did not affect antigen-induced bronchial contractions, even after pretreatment with the CysLT1-receptor specific antagonist, montelukast. However, in the bronchus isolated from one of the 2 asthma subjects, antagonism of CysLT2 receptors suppressed contractions, and dual antagonism of CysLT1 and CysLT2 receptors resulted in additive inhibitory effect on anaphylactic contractions. CONCLUSIONS: CysLT2 receptors were expressed in lung specimens isolated from asthma subjects. Activation of CysLT2 receptors may contribute to antigen-induced bronchoconstriction in certain asthma population.

Effects of ONO-6950, a novel dual cysteinyl leukotriene 1 and 2 receptors antagonist, in a guinea pig model of asthma.

We assessed in this study the anti-asthmatic effects of ONO-6950, a novel cysteinyl leukotriene 1 (CysLT1) and 2 (CysLT2) receptors dual antagonist, in normal and S-hexyl glutathione (S-hexyl GSH)-treated guinea pigs, and compared these effects to those of montelukast, a CysLT1 selective receptor antagonist. Treatment with S-hexyl GSH reduced animals LTC4 metabolism, allowing practical evaluation of CysLT2 receptor-mediated airway response. ONO-6950 antagonized intracellular calcium signaling via human and guinea pig CysLT1 and CysLT2 receptors with IC50 values of 1.7 and 25 nM, respectively (human receptors) and 6.3 and 8.2 nM, respectively (guinea pig receptors). In normal guinea pigs, both ONO-6950 (1 or 0.3 mg/kg, p.o.) and the CysLT1 receptor antagonist montelukast (0.3 or 0.1 mg/kg, p.o.) fully attenuated CysLT1-mediated bronchoconstriction and airway vascular hyperpermeability induced by LTD4. On the other hand, in S-hexyl GSH-treated guinea pigs ONO-6950 at 3 mg/kg, p.o. or more almost completely inhibited bronchoconstriction and airway vascular hyperpermeability elicited by LTC4, while montelukast showed only partial or negligible inhibition of these airway responses. In ovalbumin sensitized guinea pigs, treatment with S-hexyl GSH on top of pyrilamine and indomethacin rendered antigen-induced bronchoconstriction sensitive to both CysLT1 and CysLT2 receptor antagonists. ONO-6950 strongly inhibited this asthmatic response to the level attained by combination therapy with montelukast and BayCysLT2RA, a selective CysLT2 receptor antagonist. These results clearly demonstrate that ONO-6950 is an orally active dual CysLT1/LT2 receptor antagonist that may provide a novel therapeutic option for patients with asthma.

Discovery of Gemilukast (ONO-6950), a Dual CysLT1 and CysLT2 Antagonist As a Therapeutic Agent for Asthma.

An orally active dual CysLT1 and CysLT2 antagonist possessing a distinctive structure which consists of triple bond and dicarboxylic acid moieties is described. Gemilukast (ONO-6950) was generated via isomerization of the core indole and the incorporation of a triple bond into a lead compound. Gemilukast exhibited antagonist activities with IC50 values of 1.7 and 25 nM against human CysLT1 and human CysLT2, respectively, and potent efficacy at an oral dose of 0.1 mg/kg given 24 h before LTD4 challenge in a CysLT1-dependent guinea pig asthmatic model. In addition, gemilukast dose-dependently reduced LTC4-induced bronchoconstriction in both CysLT1- and CysLT2-dependent guinea pig asthmatic models, and it reduced antigen-induced constriction of isolated human bronchi. Gemilukast is currently being evaluated in phase II trials for the treatment of asthma.

Leukotriene C4 induces bronchoconstriction and airway vascular hyperpermeability via the cysteinyl leukotriene receptor 2 in S-hexyl glutathione-treated guinea pigs.

Cysteinyl leukotrienes act through G-protein-coupled receptors termed cysteinyl leukotriene 1 (CysLT1) and cysteinyl leukotriene 2 (CysLT2) receptors. However, little is known about the pathophysiological role of CysLT2 receptors in asthma. To elucidate the possible involvement of CysLT2 receptors in bronchoconstriction and airway vascular hyperpermeability, we have established a novel guinea pig model of asthma. In vitro study confirmed that CHO-K1 cells, expressing guinea pig CysLT2 and CysLT1 receptors are selectively stimulated by LTC4 and LTD4, respectively. However, when LTC4 was intravenously injected to guinea pigs, the resulting bronchoconstriction was fully abrogated by montelukast, a CysLT1 receptor antagonist, indicating rapid metabolism of LTC4 to LTD4 in the lung. We found that treatment with S-hexyl glutathione (S-hexyl GSH), an inhibitor of gamma-glutamyl transpeptidase, significantly increased LTC4 content and LTC4/(LTD4 plus LTE4) ratio in the lung. Under these circumstances, LTC4-induced bronchoconstriction became resistant to montelukast, but sensitive to Compound A, a CysLT2 receptor antagonist, depending on the dose of S-hexyl GSH. Combination with montelukast and Compound A completely abrogated this spasmogenic response. Additionally, we confirmed that LTC4 elicits airway vascular hyperpermeability via CysLT2 receptors in the presence of high dose of S-hexyl GSH as evidenced by complete inhibition of LTC4-induced hyperpermeability by Compound A, but not montelukast. These results suggest that CysLT2 receptors mediate bronchoconstriction and airway vascular hyperpermeability in guinea pigs and that the animal model used in this study may be useful to elucidate the functional role of CysLT2 receptors in various diseases, including asthma.