Emerging drugs for asthma

Network pharmacology-based study of the protective mechanism of conciliatory anti-allergic decoction on asthma

BACKGROUND

This study aimed to explore the underlying anti-asthma pharmacological mechanisms of conciliatory anti-allergic decoction (CAD) with a network pharmacology approach.

METHODS

Traditional Chinese medicine related databases were utilized to screen the active ingredients of CAD. Targets of CAD for asthma treatment were also identified based on related databases. The protein-protein interaction network, biological function and KEGG pathway enrichment analysis, and molecular docking of the targets were performed. Furthermore, an asthma mouse model experiment involving HE staining, AB-PAS staining, and ELISA was also performed to assess the anti-asthma effect of CAD.

RESULTS

There were 77 active ingredients in CAD, including quercetin, kaempferol, stigmasterol, luteolin, cryptotanshinone, beta-sitosterol, acacetin, naringenin, baicalin, and 48 related targets for asthma treatment, mainly including TNF, IL4, IL5, IL10, IL13 and IFN-γ, were identified with ideal molecular docking binding scores by network pharmacology analysis. KEGG pathway analysis revealed that these targets were directly involved in the asthma pathway, Th1 and Th2 cell differentiation, and signaling pathways correlated with asthma (NF-κB, IL17, T cell receptor, TNF, JAK-STAT signaling pathways, etc.). Animal experiments also confirmed that CAD could attenuate inflammatory cell invasion, goblet cell hyperplasia and mucus secretion. The levels of the major targets TNF-α, IL4, IL5, and IL13 can also be regulated by CAD in an asthma mouse model.

CONCLUSION

The anti-asthma mechanism of CAD possibly stemmed from the active ingredients targeting asthma-related targets, which are involved in the asthma pathway and signaling pathways to exhibit therapeutic effects.

Experimental Glucocorticoid Receptor Agonists for the Treatment of Asthma: A Systematic Review

Inhaled corticosteroids (ICSs) are considered the cornerstone of asthma treatment. Despite the solid evidence documenting the efficacy and safety of ICSs at the level of the airways, their use can be affected by pulmonary and systemic adverse events (AEs) when administered chronically and/or at high doses. Thus, there is a pharmacological and medical need for new glucocorticoid (GC) receptor (GR) ligands with a more favorable therapeutic index, in order to overcome the shortcomings of currently available ICSs. The therapeutic profile of GCs can be improved by enhancing genomic mechanisms mediated by transrepression, which is assumed to be responsible for several anti-inflammatory and immunomodulatory actions, rather than transactivation, which causes most of the GC-associated AEs. It was assumed that an independent modulation of the molecular mechanisms underlying transactivation and transrepression could translate into the dissociation of beneficial effects from AEs. Therefore, current research is looking for GCs that are able to elicit prevalently transrepression with negligible transactivating activity. These compounds are known as selective glucocorticoid receptor agonists (SEGRAs). In this review, experimental GR agonists currently in pre-clinical and clinical development for the treatment of asthma have been systematically assessed. Several compounds are currently under pre-clinical development, but only three novel experimental GR agonists (GW870086X, AZD5423, AZD7594) seem to have some potential therapeutic relevance and have entered clinical trials for the treatment of asthma. Since data from pre-clinical studies have not always been confirmed in clinical investigations, well-designed randomized controlled trials are needed in asthmatic patients to confirm the potentially positive benefit/risk ratio of each specific SEGRA and to optimize the development strategy of these agents in respiratory medicine.

Novel glucocorticoid receptor agonists in the treatment of asthma

INTRODUCTION

Inhaled corticosteroids are the only drugs that effectively suppress the airway inflammation, but they can induce considerable systemic and adverse effects when they are administered chronically at high doses. Consequently, the pharmaceutical industry is still searching for newer entities with an improved therapeutic index.

AREAS COVERED

Herein, the authors review the research in the glucocorticoid field to identify ligands of the glucocorticoid receptor (GR). These ligands preferentially induce transrepression with little or no transactivating activity, in order to have a potent anti-inflammatory action and a low side-effects profile.

EXPERT OPINION

Several agents have been synthesized, but few have been tested in experimental models of asthma. Furthermore, only three (BI-54903, GW870086X and AZD5423) have entered clinical development, although the development of at least one of them (BI-54903) was discontinued. The reason for the limited success so far obtained is that the model of transactivation versus transrepression is a too simplistic representation of GR activity. It is difficult to uncouple the therapeutic and harmful effects mediated by GR, but some useful information that might change the current perspective is appearing in the literature. The generation of gene expression 'fingerprints' produced by different GR agonists in target and off-target human tissues could be useful in identifying drug candidates with an improved therapeutic ratio.

Toxicological in vitro and subchronic evaluation of LASSBio-596

LASSBio-596, 2-[4-(1,4-tiazinan-4-ylsulfonyl) phenylcarbamoyl] benzoic acid, is an achiral compound containing a subunit carboxylic amide, was capable of preventing induced mechanical and morphological changes in the lungs that commonly caused the onset of asthma. Previous studies to determine the acute toxicity of oral LASSBio-596 at dose of 2000mg/kg caused no deaths in any of the tested animals. To further evaluate the safety of LASSBio-596, in vitro and in vivo tests were carried out. Regarding to in vitro test were used renal, hepatic, pulmonary, cardiac, neurologic and intestinal cell lines. They were evaluated using neutral red (NR) and [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assays. Micronuclei also was performed. Concerning to in vivo was performed subchronic on Wistar rats at doses of 10, 50, and 250mg/kg and zebrafish test. The in vitro tests results showed the safety of LASSBio-596. However, subchronic toxicity study results revealed changes in the blood parameters of amylase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose and creatine kinase (CK) which is used for cardiotoxicity evaluation, although, did not identify any histopathological alterations. However, zebrafish test demonstrated cardiac damage. It was impossible to estimate the no-observed-adverse-effect-levels and lowest observed-adverse-effect level due to the presence of cardiotoxicity in all tested doses.

Future biologic therapies in asthma

Despite the administration of appropriate treatment, a high number of patients with asthma remain uncontrolled. This suggests the need for alternative treatments that are effective, safe and selective for the established asthma phenotypes, especially in patients with uncontrolled severe asthma. The most promising options among the new asthma treatments in development are biological therapies, particularly those monoclonal antibodies directed at selective targets. It should be noted that the different drugs, and especially the new biologics, act on very specific pathogenic pathways. Therefore, determination of the individual profile of predominant pathophysiological alterations of each patient will be increasingly important for prescribing the most appropriate treatment in each case. The treatment of severe allergic asthma with anti-IgE monoclonal antibody (omalizumab) has been shown to be effective in a large number of patients, and new anti-IgE antibodies with improved pharmacodynamic properties are being investigated. Among developing therapies, biologics designed to block certain pro-inflammatory cytokines, such as IL-5 (mepolizumab) and IL-13 (lebrikizumab), have a greater chance of being used in the clinic. Perhaps blocking more than one cytokine pathway (such as IL-4 and IL-13 with dulipumab) might confer increased efficacy of treatment, along with acceptable safety. Stratification of asthma based on the predominant pathogenic mechanisms of each patient (phenoendotypes) is slowly, but probably irreversibly, emerging as a tailored medical approach to asthma, and is becoming a key factor in the development of drugs for this complex respiratory syndrome.

Identification of 2-(2-(1-naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid (setipiprant/ACT-129968), a potent, selective, and orally bioavailable chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) antagonist

Herein we describe the discovery of the novel CRTh2 antagonist 2-(2-(1-naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid 28 (setipiprant/ACT-129968), a clinical development candidate for the treatment of asthma and seasonal allergic rhinitis. A lead optimization program was started based on the discovery of the recently disclosed CRTh2 antagonist 2-(2-benzoyl-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid 5. An already favorable and druglike profile could be assessed for lead compound 5. Therefore, the lead optimization program mainly focused on the improvement in potency and oral bioavailability. Data of newly synthesized analogs were collected from in vitro pharmacological, physicochemical, in vitro ADME, and in vivo pharmacokinetic studies in the rat and the dog. The data were then analyzed using a traffic light selection tool as a visualization device in order to evaluate and prioritize candidates displaying a balanced overall profile. This data-driven process and the excellent results of the PK study in the rat (F = 44%) and the dog (F = 55%) facilitated the identification of 28 as a potent (IC50 = 6 nM), selective, and orally available CRTh2 antagonist.

Zinc-rich inhibitor of apoptosis proteins (IAPs) as regulatory factors in the epithelium of normal and inflamed airways

Integrity of the airway epithelium (AE) is important in the context of inhaled allergens and noxious substances, particularly during asthma-related airway inflammation where there is increased vulnerability of the AE to cell death. Apoptosis involves a number of signaling pathways which activate procaspases leading to cleavage of critical substrates. Understanding the factors which regulate AE caspases is important for development of strategies to minimize AE damage and airway inflammation, and therefore to better control asthma. One such factor is the essential dietary metal zinc. Zinc deficiency results in enhanced AE apoptosis, and worsened airway inflammation. This has implications for asthma, where abnormalities in zinc homeostasis have been observed. Zinc is thought to suppress the steps involved in caspase-3 activation. One target of zinc is the family of inhibitor of apoptosis proteins (IAPs) which are endogenous regulators of caspases. More studies are needed to identify the roles of IAPs in regulating apoptosis in normal and inflamed airways and to study their interaction with labile zinc ions. This new information will provide a framework for future clinical studies aimed at monitoring and management of airway zinc levels as well as minimising airway damage and inflammation in asthma.

Asthma in primary care: a case-based review of pharmacotherapy

Asthma remains a significant public health burden in the United States. Primary care providers are in an ideal position to be able to target treatment for their patients on an individual basis. It is important to determine the level of control and then base treatment on both the severity and activity of disease and the ability of the patient to be adherent to the therapy regimen. Because prescription medications along with office visits represent most asthma expenses, it is imperative to choose wisely from among the quick-relief and the long-term control medications to find the right choice for your patient.