Update on montelukast and its role in the treatment of asthma, allergic rhinitis and exercise-induced bronchoconstriction

Association between Sex-Related ALOX5 Gene Polymorphisms and Lung Atopy Risk

Atopy is an exaggerated IgE-mediated immune response to foreign antigens in which metabolic abnormalities of the leukotrienes (LTs) pathway play a crucial role. Recent studies have described sex as a key variable in LT biosynthesis, partly explaining why treatment with anti-LT drugs in atopic subjects leads to better control of symptoms in women. In addition, variability in LT production is often associated with single nucleotide polymorphisms (SNPs) in the arachidonate 5-lipoxygenase (ALOX5) gene, which encodes the leukotriene-synthesizing enzyme machinery, 5-lipoxygenase (5-LO). This study aimed to investigate whether two SNPs of ALOX5 are implicated in sex differences in allergic diseases in a prospective cohort of 150 age- and sex-matched atopic and healthy subjects. Rs2029253 and rs2115819 were genotyped using allele-specific RT-PCR, and serum levels of 5-LO and LTB4 were measured by ELISA. Both polymorphisms are significantly more common in women than in men, and their influences on LT production vary as a function of sex, leading to a decrease in men's and an increase in women's serum levels of 5-LO and LTB4. These data represent a new resource for understanding sex-related differences in lung inflammatory diseases, partly explaining why women are more likely to develop allergic disorders than men.

Risk of Neuropsychiatric Diseases According to the use of a Leukotriene Receptor Antagonist in Middle-Aged and Older Adults with Asthma: a Nationwide Population-Based Study Using Health Claims Data in Korea

BACKGROUND

Although a leukotriene receptor antagonist (LTRA) is an effective drug for asthma, there has been increasing concern regarding neuropsychiatric (NP) adverse reactions. However, evidence for this association is not sufficient, especially in adults.

OBJECTIVE

To investigate the association between the use of an LTRA and the risk of developing NP diseases in adults with asthma.

METHODS

We performed a nationwide, retrospective, cohort study using data from the National Health Insurance Service-Health Screening Cohort (NHIS-HEALS). We selected asthma patients with no previous use of an LTRA, and NP outcomes were defined by the registration of certain International Classification of Diseases, 10th Revision codes (F00-F59) during follow-up. We obtained the hazard ratio (HR) for NP diseases according to the use of an LTRA.

RESULTS

Overall, 61,571 asthma patients without LTRA experience were enrolled, and 12,168 of them took an LTRA during the follow-up period. In the adjusted model, the HR for newly diagnosed NP diseases showed no significant difference according to use of an LTRA (HR 1.01; 95% confidence interval 0.83-1.23; P = .952). Subgroup analysis for associations between duration of LTRA use and risk of NP disease indicated no significance for all groups (<6, 6 to <12, 12 to <24, and ≥24 months). Common NP diseases included dementia (75.4% vs 76.1%), mood disorders (12.68% vs 12.80%), and panic disorders (5.63% vs 3.53%) in LTRA users and non-LTRA users, respectively, and there was no significant difference in the prevalence of each NP disease in either group.

CONCLUSIONS

The current study showed the use or duration of LTRA exposure was not associated with the occurrence of NP diseases in Korean adult asthmatics.

Modulation of autophagy and transient receptor potential vanilloid 4 channels by montelukast in a rat model of hemorrhagic cystitis

AIMS

Hemorrhagic cystitis (HC) is a major urotoxic complication of cyclophosphamide (CPA) therapy. This study investigated the uroprotective effect of montelukast on CPA-induced HC, compared to the efficacy of 2-mercaptoethane sulfonate sodium (MESNA).

MAIN METHODS

Male albino rats were pretreated with MESNA (40 mg/kg/day, IP) or montelukast (10 mg/kg/day, orally) for three days then received a single dose of CPA (200 mg/kg, IP), 1 h after the last dose, and compared to CPA-treated rats receiving drug vehicle. Age-matched rats were used as controls. Bladders of rats were assessed biochemically, macroscopically and microscopically by light and electron microscope 24 h later.

KEY FINDINGS

CPA injection contributed to increased bladder weight, urothelial ulceration, vascular congestion, hemorrhage, increased collagen deposition and mast cell infiltration, compared to control rats. Montelukast preconditioning suppressed mast cell infiltration and inflammatory mediators to greater extent than MESNA. Also, montelukast enhanced autophagosomes formation in detrusor myocytes and up-regulated the autophagy-related proteins (beclin-1 & LC3-II), likely through inhibition of phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. Montelukast preconditioning offset the up-regulation of transient receptor potential vanilloid 4 (TRPV4) in urothelial tissue of CPA-treated rats, to greater extent than MESNA.

SIGNIFICANCE

These results demonstrate the uroprotective effect of montelukast on CPA-induced HC, which appears to be more superior to MESNA. These findings suggest that montelukast can emerge as a novel strategy to protect against CPA-induced urotoxicity.

Targeting SARS-CoV-2 RNA-dependent RNA polymerase: An in silico drug repurposing for COVID-19

Background: The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), took more lives than combined epidemics of SARS, MERS, H1N1, and Ebola. Currently, the prevention and control of spread are the goals in COVID-19 management as there are no specific drugs to cure or vaccines available for prevention. Hence, the drug repurposing was explored by many research groups, and many target proteins have been examined. The major protease (M pro), and RNA-dependent RNA polymerase (RdRp) are two target proteins in SARS-CoV-2 that have been validated and extensively studied for drug development in COVID-19. The RdRp shares a high degree of homology between those of two previously known coronaviruses, SARS-CoV and MERS-CoV. Methods: In this study, the FDA approved library of drugs were docked against the active site of RdRp using Schrodinger's computer-aided drug discovery tools for in silico drug-repurposing. Results: We have shortlisted 14 drugs from the Standard Precision docking and interaction-wise study of drug-binding with the active site on the enzyme. These drugs are antibiotics, NSAIDs, hypolipidemic, coagulant, thrombolytic, and anti-allergics. In molecular dynamics simulations, pitavastatin, ridogrel and rosoxacin displayed superior binding with the active site through ARG555 and divalent magnesium. Conclusion: Pitavastatin, ridogrel and rosoxacin can be further optimized in preclinical and clinical studies to determine their possible role in COVID-19 treatment.

Efficacy of Chinese Medicine Acupoint Application Combined with Montelukast on Children with Perennial Allergic Rhinitis: A Randomized Controlled Trial

OBJECTIVE

To evaluate the efficacy of Chinese medicine acupoint application (CMAA) combined with Western medicine for perennial allergic rhinitis (PAR) in children.

METHODS

In this prospective, parallel, randomized, placebo-controlled and single-blind trial from August to September, 2017, 180 children with PAR were randomly assigned to an integrative group (CMAA and Montelukast), CMAA group (CMAA and placebo tablet), or Montelukast group (placebo CMAA and Montelukast). Participants were applied with CMAA for 6 sessions over 2 weeks, and/or Montelukast Chewable Tablet orally once daily for 12 weeks. The changes in severity of symptoms were measured by Visual Analog Scale (VAS) and rhinitis control assessment test (RCAT) at 0, 2, 4 and 12 weeks of treatment. Blood samples were collected for serum interleukin-4, interferon gamma γ and T helper type 1 (Th1)/Th2 flow cytometric analysis at the time points of 0, 4 and 12 weeks.

RESULTS

Eight cases dropped out from the trial, 3 in the integrative group, 2 in the CMAA group and 3 in the Montelukast group. The VAS scores decreased significantly while the RCAT scores increased significantly in all three groups at 4 and 12 weeks compared with baseline (P<0.01 or P<0.05). The VAS scores were significantly lower while the RCAT scores were significantly higher in the integrative and CMAA groups than the Montelukast group at 2 and 4 weeks (P<0.01 or P<0.05). At 2, 4 and 12 weeks, the scores of nasal congestion, sneezing, sleep problem, and rhinitis symptom control in the integrative and CMAA groups increased significantly compared with baseline (P<0.01 or P<0.05). The least percentages of Th2 and the most alleviated Th2 shift (highest Th1/Th2) were observed in the integrative group at 12 weeks compared with the other two groups (P<0.05).

CONCLUSION

The combination of CMAA with Montelukast might be more effective and appropriate than either option alone for children with PAR. (Registered at Chinese Clinical Trial Register, registration No. ChiCTR-IOR-17012434).

HMGB1 in the Pathogenesis of Nasal Inflammatory Diseases and its Inhibition as New Therapeutic Approach: A Review from the Literature

Introduction  This study is a systematic review on recent developments about the importance of HMGB1 protein in the pathogenesis of rhino-sinusal inflammatory diseases. We also report data on the use of 18-β-glycyrrhetic acid (GA), which has been shown able to inhibit the pro-inflammatory activities of HMGB1, in young patients affected by allergic rhinitis and complaining of nasal obstruction as main symptom.

Objectives  The objective of this study was to review the literature to demonstrate the importance of HMGB1 in the pathogenesis of nasal inflammatory disorders and understand whether the inhibition of this protein may be an efficacious and innovative therapeutic strategy for patients with rhino-sinusal inflammation.

Data Synthesis  Authors searched for pertinent articles indexed in PubMed, Scopus, and other health journals between 2004 and 2015.

In total, the authors gathered 258 articles: 219 articles through Pubmed and 39 articles from other search engines. The search terms used were as follows: HMGB1 AND “respiratory epithelium,” “airway inflammation,” “rhinitis,” “allergic rhinitis,” “rhinosinusitis,” “nasal polyposis,” “glycyrrhetic acid,” “children.”

Conclusions  Patients with severe symptoms have the highest serum levels and the highest extracellular expression of HMGB1. GA inhibits HMGB1 chemotactic and mitogenic function by a scavenger mechanism on extracellular HMGB1 accumulation stimulated by lipopolysaccharides in vitro. Treatment of allergic rhinitis with GA is not associated with local or systemic side effects in children and adults.

Montelukast medicines of today and tomorrow: from molecular pharmaceutics to technological formulations

Montelukast sodium is a leukotriene antagonist of growing interest as an alternative therapy for asthma across different age groups due to its bronchoprotective, anti-inflammatory and anti-allergic properties. Currently, montelukast is commercialized only in oral solid dosage forms, which are the favorite of adult patients but may pose challenges in administration to children of young age or patients suffering from dysphagia. This review presents a comprehensive revision of scientific reports and patents on emerging strategies for the delivery of montelukast. A common ground to these reports is the pursue of an enhanced montelukast performance, by increasing its bioavailability and physico-chemical stability. A wide variety of strategies can be found, from the formation of supramolecular adducts with cyclodextrins to encapsulation in nanoparticles and liposomes. The new dosage forms for montelukast are designed for non-enteric absorption, some for absorption in the oral cavity and another two being for local action in the nasal mucosa or in the pulmonary epithelium. The review describes the emerging delivery strategies to circumvent the current limitations to the use of montelukast that are expected to ultimately lead to the development of more patient-compliant dosage forms.

Montelukast-loaded nanostructured lipid carriers: part I oral bioavailability improvement

The purpose of the study was to formulate montelukast-loaded nanostructured lipid carrier (MNLC) to improve its systemic bioavailability, avoid hepatic metabolism and reduce hepatic cellular toxicity due to metabolites. MNLC was prepared using melt-emulsification-homogenization method. Preformulation study was carried out to evaluate drug-excipient compatibility. MNLCs were prepared using spatially different solid and liquid lipid triglycerides. CAE (DL-Pyrrolidonecarboxylic acid salt of L-cocyl arginine ethyl ester), a cationic, biodegradable, biocompatible surfactant was used to stabilize the system. MNLCs were characterized by FTIR, XRPD and DSC to evaluate physicochemical properties. MNLCs having a particle size of 181.4 ± 6.5 nm with encapsulation efficiency of 96.13 ± 0.98% were prepared. FTIR findings demonstrated no interaction between the drug and excipients of the formulation which could lead to asymmetric vibrations. DSC and XRPD study confirmed stable amorphous form of the montelukast in lipid matrix. In vitro release study revealed sustained release over a period of 24 h. In vivo single dose oral pharmacokinetic study demonstrated 143-fold improvement in bioavailability as compared to montelukast-aqueous solution. Thus, the result of this study implies that developed MNLC formulation be suitable to sustain the drug release with improvement in the bioavailability.

Pharmacodynamics, pharmacokinetics and safety of GSK2190915, a novel oral anti-inflammatory 5-lipoxygenase-activating protein inhibitor

AIM

To assess the pharmacokinetics, pharmacodynamics, safety and tolerability of the 5-lipoxygenase-activating protein inhibitor, GSK2190915, after oral dosing in two independent phase I studies, one in Western European and one in Japanese subjects, utilizing different formulations.

METHOD

Western European subjects received single (50-1000 mg) or multiple (10-450 mg) oral doses of GSK2190915 or placebo in a dose-escalating manner. Japanese subjects received three of four GSK2190915 doses (10-200 mg) plus placebo once in a four period crossover design. Blood samples were collected for GSK2190915 concentrations and blood and urine were collected to measure leukotriene B₄ and leukotriene E₄, respectively, as pharmacodynamic markers of drug activity.

RESULTS

There was no clear difference in adverse events between placebo and active drug-treated subjects in either study. Maximum plasma concentrations of GSK2190915 and area under the curve increased in a dose-related manner and mean half-life values ranged from 16-34 h. Dose-dependent inhibition of blood leukotriene B₄ production was observed and near complete inhibition of urinary leukotriene E₄ excretion was shown at all doses except the lowest dose. The EC₅₀ values for inhibition of LTB₄ were 85 nM and 89 nM in the Western European and Japanese studies, respectively.

CONCLUSION

GSK2190915 is well-tolerated with pharmacokinetics and pharmacodynamics in Western European and Japanese subjects that support once daily dosing for 24 h inhibition of leukotrienes. Doses of ≥50 mg show near complete inhibition of urinary leukotriene E₄ at 24 h post-dose, whereas doses of ≥150 mg are required for 24 h inhibition of blood LTB₄.

Effect of montelukast for treatment of asthma in cigarette smokers

OBJECTIVE

Many asthmatic patients are unable to quit cigarettes; therefore information is needed on treatment options for smokers. This study evaluates 10 mg/d montelukast and 250 μg of fluticasone propionate twice daily, each compared with placebo, in patients with self-reported active smoking (unable to quit) and asthma.

METHODS

Patients (ages 18-55 years, with asthma [≥1 year], FEV1 of 60% to 90% of predicted value, airway reversibility [≥12%], and self-reported active smoking [≥0.5 to ≤2 packs per day]) were randomized (after a 3-week, single-blind, placebo, run-in period) to 1 of 3 parallel, 6-month, double-blind treatment arms. The primary efficacy end point was the percentage of days with asthma control during treatment. Adverse experiences (AEs) were also evaluated.

RESULTS

There were 347, 336, and 336 patients randomized to montelukast, fluticasone, and placebo, respectively. The mean percentage of days with asthma control over 6 months of treatment was 45% (montelukast, P < .05 vs placebo), 49% (fluticasone, P < .001 vs placebo), and 39% (placebo); the difference between montelukast and fluticasone was not significant (P = .14). Patients with a smoking history of ≤11 pack years (the median value) tended to show more benefit with fluticasone, whereas those with a smoking history of >11 pack years tended to show more benefit with montelukast. AEs occurred in similar proportions among treatment groups.

CONCLUSIONS

In a population of asthmatic patients actively smoking cigarettes, both 10 mg/d montelukast and 250 μg of fluticasone propionate twice daily significantly increased the mean percentage of days with asthma control compared with placebo.

Role of leukotriene receptor antagonists in the management of pediatric asthma: an update

At present, the main indications for leukotriene receptor antagonists (LTRA) in pediatric asthma are as add-on therapy to inhaled corticosteroids (ICS) and as initial controller therapy in children with mild asthma, especially those who cannot or will not use ICS. LTRA are also useful for patients who have concomitant rhinitis, and patients with viral-induced wheeze and exercise-induced asthma. It should be noted that the benefits of LTRA therapy have been demonstrated in children as young as 6 months of age and recent clinical trials have further proven the benefits of LTRA in acute asthma exacerbations. However, considering the important pro-inflammatory effects that leukotrienes (LT) have in experimental models of asthma, it may seem surprising that LTRA treatment outcomes are not better and that in some clinical trials only a minority of patients could be classified as full responders. This could be explained by potential additional LT receptors that are not affected by LTRA. Such receptors could represent new therapeutic targets in asthma. Furthermore, progress in differentiating between asthma phenotypes that result from different pathogenic mechanisms, some of which may involve LT to a lesser degree, should lead to an improved, personalized use of LTRA for treating asthma.

The efficacy and tolerability of intravenous montelukast in acute asthma exacerbations in Japanese patients

OBJECTIVES

In Japan, the Asthma Prevention and Management Guidelines recommend nebulized β-agonists, IV (intravenous) drip corticosteroids, as well as IV drip aminophylline for acute asthma treatment. However, current treatment for acute asthma provides inadequate benefit for some patients. We evaluated the efficacy and safety of IV montelukast added to standard therapy in Japanese patients with acute asthma exacerbations.

METHODS

This multicenter, randomized, double-blind, parallel-group study compared IV montelukast 7 mg, 14 mg, and placebo in Japanese patients with acute asthma exacerbations (N = 242). Fifteen- to sixty-five-year-old patients with acute asthma were treated with standard care during a screening period that lasted ≤60 minutes. Patients with FEV(1) (forced expiratory volume in 1 second) ≤70 predicted were randomly allocated to one of three treatment groups. The primary end point was the time-weighted average change in FEV(1) from baseline over 60 minutes [ΔFEV(1) (0-60 minutes)] after study drug administration. Secondary end points included the time-weighted average change in FEV(1) over 20, 40, and 120 minutes [ΔFEV(1) (0-T min)].

RESULTS

IV montelukast 7 mg was significantly more effective than placebo for the time-weighted average ΔFEV(1) (0-60 minutes) [least squares (LS) mean 0.09 L vs. 0.01 L; p < .05]. IV montelukast 14 mg was also more effective than placebo (LS mean 0.17 L; p < .001). Similar improvements in time-weighted average [ΔFEV(1) (0-T min)] were seen at all time points (all p < .05). Both doses of IV montelukast demonstrated a significant increase in average ΔFEV(1) compared with placebo within 10 minutes of administration (p < .001 to p < .01). The tolerability of IV montelukast was similar to that of placebo.

CONCLUSION

IV montelukast was significantly more effective than placebo in the improvement of ΔFEV(1) in Japanese patients, suggesting its role as an adjunctive therapy to existing guideline recommendations.

Enhanced vascular permeability is hypothesized to promote inflammation-induced carcinogenesis and tumor development via extravasation of large molecular proteins into the tissue

We propose that the growth of solid tumors is dependent, in part, on the entry of large molecular blood-borne growth regulators into the tissue and is facilitated by the highly permeable nature of tumor blood vessels. There is abundant evidence that the tumor vasculature is hyperpermeable and tumor growth is dependent on mediators that increase vascular permeability (e.g., VEGF and mast cells). Therefore, the extravasation of plasma proteins into the interstitial space could be an important determinant of tumor growth. Angiogenesis promotes cancer by creating a network of blood vessels that supplies oxygen and nutriment. A highly permeable vasculature could complement this by facilitating the entry of plasma proteins into the tumor space, permitting them to exert effects on growth and survival pathways. Plasma proteins could act directly (on the cancer cells) or indirectly (via the stroma), and could conceivably stimulate cell proliferation, enhance cell survival, promote angiogenesis, and/or provide the cells with essential nutrients. Since increased vascular permeability is a hallmark of inflammation and since chronic inflammation is a forerunner to cancer, we also suggest that the prolonged influx of plasma proteins during chronic inflammation could contribute to the carcinogenic process. Perhaps over time and in sufficient quantity, the extruded plasma proteins and the attendant edema set up a feed-forward cycle that exacerbates the inflammation and potentiates the formation of mutagens and growth regulators. It is tempting to speculate that differences in tumor growth/metastasis and patient outcome are at least partly due to the degree of permeability of the tumor vasculature.

The efficacy and tolerability of inhaled montelukast plus inhaled mometasone compared with mometasone alone in patients with chronic asthma

BACKGROUND

The efficacy of oral montelukast in chronic asthma is well established. Montelukast is also an effective adjunctive therapy to inhaled corticosteroids (ICS) in asthma uncontrolled on ICS alone. Inhaled montelukast was recently shown to provide significant bronchodilation compared with placebo in patients with chronic asthma. The purpose of this study was to evaluate the efficacy of inhaled montelukast added to inhaled mometasone.

METHODS

This was an 8-week, multicenter, randomized, double-blind, placebo-controlled study comparing once-daily inhaled montelukast 1 mg plus inhaled mometasone 220 μg (delivered by separate dry powder inhalers) with placebo plus inhaled mometasone 220 μg. Men and women aged 15-85 years with chronic asthma, forced expiratory volume in 1 second (FEV(1)) 50-80% of the predicted value, and β-agonist reversibility ≥12% were eligible. Patients were required to meet a minimum symptom threshold while receiving open-label inhaled mometasone during a 3-week prestudy/run-in period. Patients received blinded (montelukast vs. placebo) treatment for 2 weeks, entered a 1-week washout period, then crossed over to the other treatment for 2 weeks. The primary endpoint was the average change from baseline in FEV(1) over the 2-week treatment period. Secondary endpoints included daytime and nighttime symptom scores. Other endpoints included short-acting β-agonist (SABA) use, asthma exacerbations, asthma control, peak expiratory flow (PEF), and blood eosinophil count.

RESULTS

A total of 134 patients were randomized. For the primary endpoint, change from baseline in FEV(1), inhaled montelukast plus inhaled mometasone was significantly more effective than placebo plus inhaled mometasone (least squares mean 0.22 L vs. 0.17 L; p = .033 [two-sided at α = 0.05]). Inhaled montelukast plus inhaled mometasone was also significantly more effective than placebo plus inhaled mometasone in improving daytime asthma symptom scores (p = .005) and nighttime asthma symptom scores (p = .015), increasing the percentage of days with asthma control (p = .004), decreasing the percentage of days with asthma exacerbations (p ≤ .001), and decreasing the blood eosinophil count (p = .013). Differences were not significant on AM or PM PEF or SABA use, although the latter approached significance (p = .073). Both treatments were well tolerated.

CONCLUSION

Inhaled montelukast plus inhaled mometasone was significantly more effective than placebo plus inhaled mometasone in improving FEV(1), symptoms, asthma control, and blood eosinophil count.

A phase I randomized, placebo-controlled, dose-exploration study of single-dose inhaled montelukast in patients with chronic asthma

BACKGROUND

The efficacy of oral montelukast has been well established in asthma and allergic rhinitis in adults and children. The purpose of this study was to evaluate dose-related bronchodilation and tolerability of inhaled montelukast.

METHODS

Randomized, double-blind, crossover, adaptive-design study comparing single-dose administration of inhaled montelukast versus placebo in patients age 15-65 years with chronic asthma (n = 68). Montelukast was delivered as a witnessed dose through dry powder inhaler at doses of 25, 250, or 1000 μg, and doses of 50, 100, and 500 μg could be used if needed based on a prespecified dose-response algorithm. Each administration was followed by a 4- to 7-day washout period before crossing over to the next treatment. The primary endpoint was the change from baseline in a forced expiratory volume in 1 second (FEV₁) over the first 4 hours after administration, calculated as a time-weighted average (ΔFEV₁ [0-4 hours]). Other endpoints included the onset and duration of bronchodilation and the effect of albuterol when added to inhaled montelukast.

RESULTS

Over 4 hours postdose, and compared with placebo (least-squares [LS] mean 0.03 L), inhaled montelukast 100 μg (0.13 L; p ≤ .001), 250 μg (0.10 L; p < .01), and 1000 μg (0.12 L; p ≤ .001) had significantly greater ΔFEV₁ (0-4 hours). At 24 hours postdose, inhaled montelukast 100 μg (0.10 L) and 1000 μg (0.09 L) had significantly greater bronchodilation compared with placebo (0.02 L; p < .05 vs. montelukast). Montelukast 1000 μg provided significant bronchodilation versus placebo within 20 minutes of administration (0.03 L vs. -0.05 L), whereas montelukast 100 μg provided significant bronchodilation relative to placebo within 2 hours of dosing (0.09 L vs. 0.01 L). Montelukast (pooled doses) plus albuterol was significantly more effective than montelukast plus placebo for ΔFEV₁ (0-90 minutes) (0.34 L vs. 0.15 L; p = .015). The tolerability of inhaled montelukast was similar to that of placebo. No serious adverse experiences were reported.

CONCLUSIONS

Inhaled montelukast provided significant bronchodilation compared with placebo as early as 20 minutes after the administration that persisted for 24 hours and provided additive bronchodilation to albuterol.

The discovery of setileuton, a potent and selective 5-lipoxygenase inhibitor

The discovery of novel and selective inhibitors of human 5-lipoxygenase (5-LO) is described. These compounds are potent, orally bioavailable, and active at inhibiting leukotriene biosynthesis in vivo in a dog PK/PD model. A major focus of the optimization process was to reduce affinity for the human ether-a-go-go gene potassium channel while preserving inhibitory potency on 5-LO. These efforts led to the identification of inhibitor (S)-16 (MK-0633, setileuton), a compound selected for clinical development for the treatment of respiratory diseases.

Cysteinyl leukotrienes acting via granule membrane-expressed receptors elicit secretion from within cell-free human eosinophil granules

BACKGROUND

Cysteinyl leukotrienes (cysLTs) are recognized to act via receptors (cysLTRs) expressed on cell surface plasma membranes. Agents that block cysLT(1) receptor (cysLT(1)R) are therapeutics for allergic disorders. Eosinophils contain multiple preformed proteins stored within their intracellular granules. Cell-free eosinophil granules are present extracellularly as intact membrane-bound organelles in sites associated with eosinophil infiltration, including asthma, rhinitis, and urticaria, but have unknown functional capabilities.

OBJECTIVE

We evaluated the expression of cysLTRs on eosinophil granule membranes and their functional roles in eliciting protein secretion from within eosinophil granules.

METHODS

We studied secretory responses of human eosinophil granules isolated by subcellular fractionation. Granules were stimulated with cysLTs, and eosinophil cationic protein and cytokines were measured in the supernatants. Receptor expression on granule membranes and eosinophils was evaluated by flow cytometry and Western blot.

RESULTS

We report that receptors for cysLTs, cysLT(1)R, cysLT(2) receptor, and the purinergic P2Y12 receptor, are expressed on eosinophil granule membranes. Leukotriene (LT) C(4) and extracellularly generated LTD(4) and LTE(4) stimulated isolated eosinophil granules to secrete eosinophil cationic protein. MRS 2395, a P2Y12 receptor antagonist, inhibited cysLT-induced eosinophil cationic protein release. Montelukast, likely not solely as an inhibitor of cysLT(1)R, inhibited eosinophil cationic protein release elicited by LTC(4) and LTD(4) as well as by LTE(4).

CONCLUSION

These studies identify previously unrecognized sites of localization, the membranes of intracellular eosinophil granule organelles, and function for cysLT-responsive receptors that mediate cysteinyl leukotriene-stimulated secretion from within eosinophil granules, including those present extracellularly.

Exercise-induced asthma: critical analysis of the protective role of montelukast

Exercise-induced asthma/exercise-induced bronchospasm (EIA/EIB) is a prevalent and clinically important disease affecting young children through older adulthood. These terms are often used interchangeably and the differences are not clearly defined in the literature. The pathogenesis of EIA/EIB may be different in those with persistent asthma compared to those with exercise-induced symptoms only. The natural history of EIA is unclear and may be different for elite athletes. Leukotriene biology has helped the understanding of EIB. The type and intensity of exercise are important factors for EIB. Exercise participation is necessary for proper development and control of EIA is recommended. Symptoms of EIB should be confirmed by proper testing. Biologic markers may also be helpful in diagnosis. Not all exercise symptoms are from EIB. Many medication and nonpharmacologic treatments are available. Asthma education is an important component of managing EIA. Many medications have been tested and the comparisons are complicated. Montelukast is a US Food and Drug Administration-approved asthma and EIB controller and has a number of potential advantages to other asthma medications including short onset of action, ease of use, and lack of tolerance. Not all patients improve with montelukast and rescue medication should be available.

Leukotriene modifiers in the treatment of asthma in children

Asthma is one of the most common respiratory disorders in clinical practice, affecting up to 13% of people worldwide. Inflammation is the most important component of asthma and inhaled corticosteroids (ICS) are recommended as the first line controller treatment for patients of all ages. Treatment with corticosteroids is often unable to fully control asthma symptoms and progression. Recently, leukotrienes have come to the forefront of research as they have been found play a pivotal role in the airway inflammatory process, and specific drugs have been developed to target them. Cysteiny leukotriene antagonists (LTRAs) have recently emerged as important therapeutic options that show a large potential clinical utility. Three specific LTRAs are licensed for clinical use: montelukast, zafirlukast and pranlukast, although montelukast is the only drug approved in the paediatric age range. It is well tolerated (although adverse effects such as headaches, abdominal pain, rashes, angioedema, pulmonary eosinophilia and arthralgia have been reported) and shows many positive effects in asthmatic patients. Current Global Initiative for Asthma guidelines recommend LTRAs as: (1) a second choice treatment to ICS for patients with mild persistent asthma, (2) an add-on therapy to reduce the dose of ICS in patients with moderate or severe asthma, due to the different and complementary mechanisms of action of these agents. LTRAs may be particularly appropriate choices in a number of clinical situations, including the following: patients with concomitant rhinitis; patients with viral-induced wheeze; patients with exercise-induced bronchoconstriction (EIB) and, in children aged 2-5 years, to reduce the frequency of asthma exacerbations.

Clinical studies of the DP1 antagonist laropiprant in asthma and allergic rhinitis

BACKGROUND

Prostaglandin D(2) is a proinflammatory mediator believed to be important in asthma and allergic rhinitis (AR). Allelic variants in the prostaglandin D(2) receptor type 1 (DP1) gene (PTGDR) have been suggested to be associated with asthma susceptibility.

OBJECTIVES

We sought to investigate the efficacy of the DP1 antagonist laropiprant (alone or with montelukast) in asthma and seasonal AR and explore whether sequence variations in PTGDR are associated with asthma severity.

METHODS

For asthma, in a double-blind crossover study, 100 patients with persistent asthma were randomized to placebo or laropiprant, 300 mg/d for 3 weeks, followed by addition of montelukast, 10 mg/d for 2 weeks. PTGDR promoter haplotypes were categorized as high, medium, or low transcriptional efficiency. The primary efficacy end point was FEV(1). For AR, in a double-blind parallel-group study, 767 patients sensitized to a regionally prevalent fall allergen with symptomatic fall rhinitis were allocated to laropiprant, 25 mg/d or 100 mg/d; cetirizine, 10mg/d; or placebo for 2 weeks. The primary end point was the Daytime Nasal Symptoms Score.

RESULTS

For asthma, no significant differences in FEV(1) or asthma symptoms were noted for laropiprant versus placebo or laropiprant plus montelukast vs montelukast (differences between montelukast and placebo: P <or= .001). No clear association was seen between haplotype pair (ie, diplotype) and asthma severity. For AR, although cetirizine (vs placebo) demonstrated an improvement in the Daytime Nasal Symptoms Score (P < .001), laropiprant did not.

CONCLUSION

Laropiprant did not demonstrate efficacy in asthmatic patients or patients with AR. Variations in PTGDR did not appear related to baseline asthma severity or treatment response (NCT00533208; NCT00783601).

The efficacy of montelukast during the allergy season in pediatric patients with persistent asthma and seasonal aeroallergen sensitivity

OBJECTIVE

To determine the effect of montelukast on asthma during the allergy season in children with persistent asthma and seasonal aeroallergen sensitivity.

DESIGN

This 3-week double-blind, placebo-controlled, parallel-group multicenter study compared daily montelukast 5 mg chewable tablets and placebo in patients 6-14 years of age with forced expiratory volume in 1 second (FEV(1)) > or = 60 and < or = 85% predicted, persistent asthma that is also active during allergy season, and documented sensitivity to seasonal allergens. Concomitant inhaled corticosteroid use was permitted in up to 40% of enrolled patients. The primary endpoint was the percentage change from baseline in FEV(1) over 3 weeks of treatment. Additional endpoints included the percentage change from baseline in beta-agonist use, average changes in daytime and nighttime symptom score, AM and PM peak expiratory flow rate (PEFR), investigator's global asthma evaluation, and parent/guardian global asthma evaluation at the end of the treatment period. Adverse experiences (AEs) were collected to assess safety and tolerability.

RESULTS

A total of 421 patients were randomized to montelukast (N = 203) or placebo (N = 218). For the primary endpoint, the percentage change from baseline FEV(1), montelukast was not significantly different from placebo (least squares mean 9.53% vs. 9.15%, respectively; p = 0.810). Compared with placebo, montelukast was associated with significantly lower (better) investigator's global asthma evaluation (LS mean 2.71 vs. 2.98; p < 0.05) and parent/guardian global asthma evaluation (LS mean: 2.63 vs. 2.90; p < 0.05) scores. There were no significant differences between treatment groups for the other efficacy evaluations. Both treatments were well tolerated, with no significant differences observed in AE rates.

CONCLUSION

Montelukast did not significantly improve FEV(1) compared with placebo over three weeks of treatment during the allergy season in pediatric patients with seasonal allergen sensitivity. (ClinicalTrials.gov identifier: NCT00289874).

Safety and tolerability of montelukast in placebo-controlled pediatric studies and their open-label extensions

BACKGROUND

Montelukast is a potent leukotriene-receptor antagonist administered once daily that provides clinical benefit in the treatment of asthma and allergic rhinitis in children and adults. Because of its wide use as a pediatric controller, there is a need for a further review of the safety and tolerability of montelukast in children.

OBJECTIVE

To summarize safety and tolerability data for montelukast from previously reported as well as from unpublished placebo-controlled, double-blind, pediatric studies and their active-controlled open-label extension/extended studies.

METHODS

These studies evaluated 2,751 pediatric patients 6 months to 14 years of age with persistent asthma, intermittent asthma associated with upper respiratory infection, or allergic rhinitis. These patients were enrolled in seven randomized, placebo-controlled, double-blind registration and post-registration studies and three active-controlled open-label extension/extended studies conducted by Merck Research Laboratories between 1995 and 2004.

RESULTS

Montelukast was well tolerated in all studies. Clinical and laboratory adverse experiences for patients treated with montelukast were generally mild and transient. The most frequent clinical adverse events for all treatments (placebo, montelukast, active control/usual care) in virtually all studies were upper respiratory infection, worsening asthma, pharyngitis, and fever.

CONCLUSION

The clinical and laboratory safety profile for montelukast was similar to that observed for placebo or active control/usual care therapies. The safety profile of montelukast did not change with long-term use.

Efficacy of add-on montelukast in patients with non-controlled asthma: a Belgian open-label study

OBJECTIVE

To evaluate the efficacy of add-on montelukast on asthma control and allergic rhinitis symptoms in asthmatic patients still symptomatic with chronic treatment with inhaled corticosteroid and long-acting beta(2) agonist (ICS/LABA), irrespective of the dose.

RESEARCH DESIGN AND METHODS

This 2-month, open-label, real-life, multicentre, observational study was undertaken by 499 general practitioners in Belgium. Patients (>or= 4 years old) with uncontrolled asthma despite fluticasone/salmeterol or budesonide/formoterol therapy had oral montelukast 4, 5, or 10 mg daily added to their therapy, depending on the registered dose for their age. Asthma control, assessed by the 6-item Juniper Asthma Control Questionnaire (ACQ) was recorded at baseline and after 2 months of treatment with montelukast and the patients' global evaluation of asthma was also recorded at the end of the study. Concomitant allergic rhinitis symptoms were evaluated according to the patients' perception.

RESULTS

A total of 5769 patients were eligible for analysis. Addition of montelukast was associated with significant decrease in mean (SD) ACQ score (from 1.97 [0.77] at baseline to 1.05 [0.69] after add-on treatment, p < 0.001). There was also a significant improvement in all individual symptoms of the ACQ score (p < 0.001). After 2 months, 89% of the patients reported global improvement of their asthma, with a good correlation between patients' global evaluation and change in ACQ scores. Of the 2442 patients who reported allergic rhinitis symptoms at baseline, 91% showed a global improvement of their asthma symptoms and 82% in their rhinitis symptoms after adding montelukast.

CONCLUSION

This open-label observational study showed an improvement, after 2 months of add-on therapy with montelukast, in both asthma and allergic rhinitis symptoms in patients not adequately controlled on a fixed association of ICS/LABA.

Relationship between cysteinyl-leukotriene-1 receptor and human transitional cell carcinoma in bladder

OBJECTIVES

To investigate the leukotriene (LT) D(4) (LTD(4)) receptor (cysteinyl-LT(1) receptor [CysLT(1)R]) expression in transitional cell carcinoma (TCC) of the bladder, as well as the effects of the CysLT(1)R antagonist on cell proliferation in TCC cell lines. The metabolism of arachidonic acid by either cyclooxygenase or lipoxygenase is thought to play an important role in carcinogenesis. LTD(4) is a pro-inflammatory mediator derived from arachidonic acid through various enzymatic steps, and 5-lipoxygenase is an important factor in generating LTD(4).

METHODS

CysLT(1)R expression in TCC tissue and normal bladder tissue was examined. CysLT(1)R expression was detected using immunohistochemistry. The effects of the CysLT(1)R antagonist on TCC cell growth were examined by 3-(4,5-dimethylthiazol-2-thiazolyl)-2,5-diphenyltetrazolium bromide assay and reverse transcriptase-polymerase chain reaction. Flow cytometry was used to determine whether the CysLT(1)R antagonist induced apoptosis.

RESULTS

Initially, only slight CysLT(1)R expression was detected in normal bladder tissues and marked CysLT(1)R expression was detected in the TCC tissues. CysLT(1)R expression was greater in high-grade cancer than in low-grade cancer. Furthermore, CysLT(1)R expression was also greater in advanced-stage cancer than in early-stage cancer. Finally, the CysLT(1)R antagonist caused marked inhibition of TCC cells by inducing early apoptosis.

CONCLUSIONS

CysLT(1)R was induced in TCC. The results suggest that the CysLT(1)R antagonist might mediate potent antiproliferative effects on TCC cells. Thus, the target of the CysLT(1)R is potentially a new therapy in the treatment of TCC.