Safety Profile and Effectiveness of Rivaroxaban for Patients With Venous Thromboembolism in Japan　- Results From Post-Marketing Surveillance (XASSENT).

BACKGROUND: The incidence of venous thromboembolism (VTE; pulmonary embolism [PE] and/or deep vein thrombosis [DVT]) in Japan is increasing, but relatively small numbers of patients from Japan have been included in studies investigating rivaroxaban (a direct factor Xa inhibitor) for the treatment of VTE and preventing its recurrence.Methods and Results: An open-label, prospective, observational study (XASSENT [NCT02558465]) investigated the safety profile and effectiveness of rivaroxaban for ≤2 years in the treatment of VTE and prevention of its recurrence in Japanese clinical practice. Primary outcomes were major bleeding and symptomatic recurrent VTE. Statistical analyses were exploratory and descriptive. Overall, 2,540 patients were enrolled (safety analysis population [SAP], n=2,387; effectiveness analysis population [EAP], n=2,386). In the SAP, >80% of patients received the approved rivaroxaban dose, the mean (standard deviation) age was 66.6 (15.0) years, ≈74% were >50 kg, and 43% had a creatinine clearance ≥80 mL/min. PE+DVT, PE only, and DVT only were reported in 42%, 8%, and 50% of patients, respectively, and active cancer in 17% of patients. Major bleeding was reported in 69 patients (2.89%; 3.60%/patient-year; SAP) and symptomatic PE/DVT recurrence in 26 patients (1.09%; 1.36%/patient-year; EAP) during the treatment period. CONCLUSIONS: XASSENT provided information on the expected proportions of bleeding and VTE recurrence during rivaroxaban treatment in Japanese clinical practice; no new concerns of safety or effectiveness were found.

Intravitreal aflibercept for diabetic macular edema in real-world clinical practice in Japan: 24-month outcomes.

PURPOSE: To report the safety and effectiveness of intravitreal aflibercept (IVT-AFL) for diabetic macular edema (DME) in the real-world clinical practice setting in Japan. METHODS: In this prospective, multicenter, observational, post-marketing surveillance, patients with DME newly receiving IVT-AFL were enrolled. During a 24-month follow-up, the primary outcome was the occurrence of safety events. Other pre-specified endpoints were effectiveness indicators, such as best-corrected visual acuity (BCVA), central retinal thickness, and injection frequency. RESULTS: In total, 646 patients administered at least one IVT-AFL injection were included in the safety analysis. During the follow-up period, adverse events occurred in 42 patients (6.50%), whereas adverse drug reactions occurred in 12 (1.86%). In the 12 patients who had adverse drug reactions, seven events occurred in seven patients within the first month of the most recent injection. In addition, 622 patients were included in the effectiveness analysis set. The number of injections over 24 months was 3.6 ± 3.0 (mean ± standard deviation [SD]). BCVA (logarithm of the minimum angle of resolution) was 0.437 ± 0.362 (mean ± SD) (n = 622) at baseline and 0.321 ± 0.348 (n = 177) after 24 months of treatment with IVT-AFL. Central retinal thickness was 440.8 ± 134.2 µm (mean ± SD) (n = 444) at baseline and 355.5 ± 126.4 µm (n = 140) at 24 months. CONCLUSION: Routine administration of IVT-AFL for DME was not associated with new safety concerns, and BCVA outcomes were maintained over 24 months in the real-world setting. Nonetheless, patients in this real-world setting received fewer injections than those in clinical trials, suggesting that a margin for improvement exists in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02425501.

Bleeding patterns of women with heavy menstrual bleeding or dysmenorrhoea using the levonorgestrel-releasing intrauterine system: results from a real-world observational study in Japan (J-MIRAI).

PURPOSE: To collect real-world safety and clinical outcome data on the levonorgestrel-releasing intrauterine system (LNG-IUS) for functional/organic heavy menstrual bleeding (HMB) and dysmenorrhoea in Japanese women (J-MIRAI). MATERIALS AND METHODS: In this prospective, multicentre, single-cohort, open-label, post-authorisation study, we assessed menstrual blood loss after LNG-IUS insertion by changes from baseline in pictorial blood loss assessment chart (PBAC) scores. Scores for the menorrhagia multi-attribute scale (MMAS) were collected for 12 months to assess quality of life. RESULTS: We included 47 patients with complete PBAC score and patient diary data. The median PBAC score before LNG-IUS insertion was 159.0, which decreased significantly to 6.0 at 12 months post-insertion; for patients with adenomyosis (n = 20), PBAC score decreased from 174.5 pre-insertion to 19.5 at 12 months. The number of patient-reported bleeding days was correlated with PBAC score ≥5. The proportion of women with prolonged bleeding decreased from 85.7% to 34.6% by the study's end. Some women reported no bleeding after the first 90-day reference period. The mean MMAS overall score significantly increased from 50.50 before insertion to 88.67 at 12 months. CONCLUSIONS: Japanese women with functional/organic HMB experienced substantial reductions in bleeding symptoms and improvements in quality of life after 12-month use of the LNG-IUS.

Large-scale, prospective observational study of regorafenib in Japanese patients with advanced gastrointestinal stromal tumors in a real-world clinical setting.

Background: Regorafenib improves overall survival (OS) of patients with advanced progressive gastrointestinal stromal tumors (GISTs) after standard chemotherapy in phase III trials in the 3rd-line setting. This large-scale, prospective observational study evaluated the safety and effectiveness of regorafenib in Japanese patients with GIST in a real-world clinical setting. Methods: Patients with GIST received oral regorafenib at a maximum daily dose of 160 mg for weeks 1-3 of each 4-week cycle (dose could be modified at investigator's discretion). The primary objective was to assess safety, particularly significant adverse drug reactions (ADRs), as well as the frequency of occurrence of ADRs, hand and foot syndrome (HFS), discontinuation of treatment due to disease progression and adverse events. A Cox proportional hazards model was used to evaluate associations between OS or time to treatment failure (TTF) and baseline characteristics or HFS. Results: Between August 2013 and March 2021, 143 evaluable patients were enrolled. ADRs occurred in 90.2% of patients and led to treatment discontinuation in 28.3%. The most frequent ADRs were HFS, hypertension, and liver injury. The overall response rate was 11.3% and disease control rate 56.5% (RECIST) based on investigators' assessments. Median OS was 17.4 months (95% CI 14.24-23.68). Median TTF was 5.3 (95% CI 4.0-6.5) months. Improved OS and TTF responses occurred in patients with an Eastern Cooperative Oncology Group performance status (ECOG-PS) of 0 or 1. Conclusion: The outcomes in this real-world study were consistent with those seen in clinical trials. No new safety concerns were identified. Clinical trial registration: https://clinicaltrials.gov, identifier NCT01933958.

Long-term surveillance provides real-world evidences of safety and effectiveness in intravitreal aflibercept treatment for age-related macular degeneration.

This prospective, multicentre, postmarketing surveillance were conducted to report on the long-term safety and effectiveness of intravitreal aflibercept (IVT-AFL) treatment in clinical practice of Japanese patients with neovascular age-related macular degeneration (nAMD) who newly initiated IVT-AFL treatment. The primary outcomes were the incidence of adverse events (AEs) and of adverse drug reactions (ADRs) over 36 months. Number of injections, timing of ADR occurrence, and some effectiveness index were also summarised. A total of 3,872 patients received 7.2 ± 5.8 (mean ± standard deviation) injections, and AEs occurred in 5.73% of patients. ADRs were reported in 2.76% of patients, with ocular and nonocular ADRs in 2.07% and 0.72% of patients, respectively. Most vitreo-retinal events developed within 6 months of initial IVT-AFL treatment, and most instances of increased intraocular pressure and cerebral infarction developed after 6 months of follow-up. Mean best-corrected visual acuity and central retinal thickness were numerically better throughout the follow-up period compared with baseline. These results indicated acceptable tolerability and effectiveness of IVT-AFL treatment in patients with nAMD in clinical practice in Japan. Information regarding the risk and the timing of ADRs is valuable for safe and effective long-term treatment of patients with nAMD.Trial registration number: NCT01756248.

Real-World Data on Intravitreal Aflibercept for Macular Edema Secondary to Central Retinal Vein Occlusion: 24-Month Outcomes.

Purpose: To report on the safety and effectiveness of intravitreal aflibercept (IVT-AFL) for macular edema secondary to central retinal vein occlusion (CRVO) in clinical practice in Japan. Patients and Methods: This prospective, noninterventional, multicenter post-authorization safety study enrolled patients who were treated with IVT-AFL for macular edema secondary to CRVO and followed up for 24 months. The primary outcome was the occurrence of safety events. Other pre-specified outcomes were indicators of effectiveness, including best corrected visual acuity (BCVA), central retinal thickness (CRT), and frequency of injections. Results: The safety analysis included 377 patients who received at least one IVT-AFL. Adverse events (AEs) occurred in 22 patients (5.84%) and adverse drug reactions occurred in 5 (1.33%) over 24 months. Of the 22 patients with AEs, 72.7% experienced their first AEs by the third injection. The effectiveness analysis set comprised 360 patients for whom data on each outcome could be collected. The number of injections over 24 months was 3.4 ± 2.4 (mean ± standard deviation [SD]). BCVA (logarithm of the minimum angle of resolution) was 0.709 ± 0.535 (mean ± SD) (n = 357) at baseline and 0.543 ± 0.559 (n = 97) after 24 months of treatment with IVT-AFL. CRT was 552.6 ± 211.3 µm (mean ± SD) (n = 214) at baseline and 331.5 ± 144.0 µm (n = 54) at 24 months. Conclusion: There were no new safety issues concerning routine administration of IVT-AFL for macular edema secondary to CRVO. BCVA recovered during 24 months of IVT-AFL treatment in the real-world setting. However, there was a trend toward less improvement compared with the results of randomized controlled trials, likely due in part to undertreatment.

Real-world outcomes of the levonorgestrel-releasing intrauterine system for heavy menstrual bleeding or dysmenorrhea in Japanese patients: A prospective observational study (J-MIRAI).

OBJECTIVES: We collected real-world data on the safety and clinical outcomes of the levonorgestrel-releasing intrauterine system (LNG-IUS) for heavy menstrual bleeding and dysmenorrhea. STUDY DESIGN: This was a prospective, multicenter, single-cohort, open-label, post-authorization 12-month follow-up study of Japanese patients initiating the LNG-IUS for heavy menstrual bleeding and/or dysmenorrhea. The primary endpoint was the safety profile based on adverse events and adverse drug reactions (ADRs), including expulsions and abnormal bleeding, within 12 months of LNG-IUS insertion. Secondary endpoints included changes from baseline in menstrual blood loss based on bleeding days and dysmenorrhea graded on a visual analog scale (VAS). RESULTS: Of the 595 patients included, many had underlying conditions such as adenomyosis (39.5%), uterine leiomyoma (30.8%), or endometriosis (12.9%). The incidences of ADRs and serious ADRs were 59.7% and 0.3%, respectively. Frequently reported ADRs were metrorrhagia (48.9%), procedural pain (14.1%), and ovarian cyst (6.2%). The cumulative incidence of expulsions at 12 months was 8.7%. Risk factors for expulsion were obesity (body mass index ≥25 kg/m2), adenomyosis, and uterine cavity length ≥8 cm. The median [interquartile range] VAS score for dysmenorrhea improved from 46.5 [13.0-68.0] at insertion to 1.0 [0.0-13.0] at 12 months, and improvements were also observed in chronic pelvic pain and painful defecation. CONCLUSIONS: The LNG-IUS safely and effectively reduced dysmenorrhea, chronic pelvic pain, and painful defecation. Risk factors for expulsion suggest that patients with underlying organic disease should be monitored carefully when using the LNG-IUS. IMPLICATIONS: The LNG-IUS is an effective treatment for secondary dysmenorrhea with organic disease, and for the reduction of chronic pelvic pain; however, physicians should be aware of the increased risk of expulsion in patients with organic conditions.

Impact of three major risk factors on clinical outcomes in patients with nonvalvular atrial fibrillation receiving rivaroxaban: Sub-analysis from the XAPASS study.

Background: To evaluate the impact of three risk factors (age [≥75 years], renal impairment [creatinine clearance <50 ml/min], and low body weight [≤50 kg]) on the risk of any bleeding events, all-cause mortality, and stroke, non-central nervous system (non-CNS) systemic embolism (SE), and myocardial infarction (MI) in patients with nonvalvular atrial fibrillation (NVAF) treated with rivaroxaban in a real-world clinical setting. Methods: The Xarelto Post-Authorization Safety and Effectiveness Study in Japanese Patients with Atrial Fibrillation (XAPASS) is a prospective, single-arm, observational study. Enrolled patients were divided into four subgroups by the number of risk factors. Results: Overall, 9823 patients were included: 4299 with low risk, 2816 with moderate risk, 1574 with high risk, and 1134 with very high risk. The hazard ratios (95% confidence interval) (reference: low risk) for the moderate-, high-, and very-high-risk groups were 1.62 (1.19, 2.21) (p = 0.002), 2.15 (1.47, 3.15) (p < 0.001), and 2.49 (1.60, 3.87) (p <0.001) for major bleeding, and 1.98 (1.47, 2.66), 2.29 (1.59, 3.29), and 2.74 (1.81, 4.16) (p <0.001 for all) for stroke/non-CNS SE/MI, respectively. Conclusions: Age ≥75 years and renal impairment, but not low body weight, were determinants for major bleeding. The accrual of three risk factors was associated with increased risk for major bleeding and stroke/non-CNS SE/MI in patients with NVAF receiving rivaroxaban; there was no increase in the cumulative risk for these with an increasing number of risk factors.

Real-world safety and effectiveness of rivaroxaban using Japan-specific dosage during long-term follow-up in patients with atrial fibrillation: XAPASS.

BACKGROUND: The Xarelto Post-Authorization Safety and Effectiveness Study in Japanese Patients with Atrial Fibrillation (XAPASS) was designed to investigate safety and effectiveness during long-term follow-up of rivaroxaban treatment, using reduced doses compared with other global regions, in Japanese patients with non-valvular atrial fibrillation in real-world clinical practice. METHODS: In this prospective, open-label, single-arm, observational study, 11,308 patients with non-valvular atrial fibrillation newly prescribed rivaroxaban (15/10 mg once daily) at 1416 sites across Japan were enrolled and followed for a mean of 2.5 years. RESULTS: In total, 10,664 and 10,628 patients were included in the safety and effectiveness analyses, respectively. In the safety population, mean (standard deviation) age was 73.1 (9.8) years and Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, previous Stroke/TIA (2 points) (CHADS2) score was 2.2 (1.3). Incidences (95% confidence intervals) of any and major bleeding were 3.77 (3.53-4.01) and 1.16 (1.03-1.29) events per 100 patient-years, respectively. Age ≥75 years, creatinine clearance <50 mL/min, diabetes mellitus, and vascular disease were independently associated with incidence of major bleeding. The primary composite effectiveness outcome of stroke, non-central nervous system systemic embolism, and myocardial infarction occurred at an incidence (95% confidence interval) of 1.32 (1.18-1.46) events per 100 patient-years. Age ≥75 years, hypertension, prior ischemic stroke/transient ischemic attack, and concomitant use of antiplatelets were independently associated with incidence of the composite outcome of stroke, non-central nervous system systemic embolism, and myocardial infarction. CONCLUSION: In the XAPASS, a large-scale study involving a broad range of patients with non-valvular atrial fibrillation newly prescribed rivaroxaban using Japan-specific dosage in real-world clinical practice, no unexpected safety or effectiveness concerns were detected during up to 5 years of follow-up.

Design and Baseline Data for a Prospective Observational Study of Rivaroxaban in Patients with Venous Thromboembolism in Japan (XASSENT).

Background The efficacy and safety of rivaroxaban have been demonstrated in phase 3 trials of patients with venous thromboembolism (VTE; pulmonary embolism [PE] and deep vein thrombosis [DVT]). Data regarding rivaroxaban treatment of VTE in routine Japanese clinical practice remain limited. Objectives XASSENT will evaluate rivaroxaban treatment of VTE in real-world Japanese clinical practice. We report the study design and baseline patient characteristics. Methods XASSENT (NCT02558465) is an open-label, prospective observational, post-marketing surveillance cohort study in patients receiving rivaroxaban treatment for VTE. Enrolment took place between November 2015 and March 2018. XASSENT will follow patients for up to 2 years. Primary outcome variables: major bleeding and symptomatic recurrent VTE. Statistical analyses are exploratory and descriptive. Results Baseline patient characteristics at June 2020 ( n = 2,299) are presented (58.2% female; mean age 66.7 years; mean weight 60.9 kg). The population encompasses patients with wide-ranging characteristics including older age, low weight, and renal dysfunction. Most participants (67.6%) had a history of VTE risk factors at baseline. Half of the population (50.4%) had DVT only; 41.4% had DVT with PE; 8.2% had PE only. Overall, 68.4% were inpatients and 77.1% had symptomatic VTE. Rivaroxaban was prescribed for initial treatment in 84.6% of patients and maintenance treatment in 15.4%. Most were prescribed the approved dose of rivaroxaban for initial (30 mg daily; 84.4%) or maintenance (15 mg daily; 81.9%) treatment of VTE in Japan. The most common reason for selecting non-recommended dose was 'elderly'. Conclusions Results from XASSENT will complement phase 3 trial data and inform clinical practice.

Mouse strain differences in immobility and sensitivity to fluvoxamine and desipramine in the forced swimming test: analysis of serotonin and noradrenaline transporter binding.

Strain differences in immobility time in the forced swimming test were investigated in five strains of mice, namely, ICR, ddY, C57BL/6, DBA/2 and BALB/c mice. There were significant strain differences. The immobility times of ICR, ddY and C57BL/6 mice were longer than those of DBA/2 and BALB/c mice. Immobility times were not significantly related to locomotor activity in these strains. There were also differences in sensitivity to the selective serotonin reuptake inhibitor (SSRI) fluvoxamine. In ICR, ddY and C57BL/6 mice, fluvoxamine did not affect immobility time, while it reduced the immobility time of DBA/2 and BALB/c mice dose-dependently. The noradrenaline reuptake inhibitor desipramine decreased immobility time in all strains of mice. Serotonin (5-HT) transporter binding in the brains of all five strains of mice was also investigated. Analysis of 5-HT transporter binding revealed significant strain differences, being lower in DBA/2 and BALB/c mice than in other strains of mice. The amount of 5-HT transporter binding was correlated to baseline immobility time. However, there was no significant relation between noradrenaline transporter binding and immobility time. These results suggest that the duration of baseline immobility depends on the levels of 5-HT transporter binding, leading to apparent strain differences in immobility time in the forced swimming test. Furthermore, differences in 5-HT transporter binding may cause variations in responses to fluvoxamine.

Synthesis of 1-arylpiperazyl-2-phenylcyclopropanes designed as antidopaminergic agents: cyclopropane-based conformationally restricted analogs of haloperidol.

A series of the cyclopropane-based conformationally restricted analogs of haloperidol were designed as potential antidopaminergic agents and were effectively synthesized using highly stereoselective Grignard reaction with tert-butanesulfinyl imines as the key step. Pharmacological evaluation of the compounds showed that the conformational restriction method can effectively work for improving the pharmacological selectivity of a parent compound and also for investigating the bioactive conformation.

Kv7.2-7.5 voltage-gated potassium channel (KCNQ2-5) opener, retigabine, reduces capsaicin-induced visceral pain in mice.

K(v)7.2-7.5 voltage-gated potassium channels (KCNQ2-5) are associated with M-current and known to distribute in the nociceptive sensory pathway (e.g., dorsal root ganglia and spinal cord). Opening of these channels leads to cell membrane hyperpolarization that results in decreased neuronal action potentials. Since, KCNQ/M-current is located in the visceral sensory system, we examined the anti-nociceptive effect of the KCNQ opener, retigabine, on visceral pain induced by an intracolonic injection of capsaicin in mice. Intraperitoneal administration of retigabine (1, 3 and 10 mg/kg) dose-dependently suppressed visceral pain behavior (i.e., the number of licking) induced by the capsaicin treatment and prolonged the latency to first licking. These data provide the first evidence that increased KCNQ channel conductance plays an inhibitory role in the visceral pain pathway.

Brain neurotransmitter receptor-binding characteristics in rats after oral administration of haloperidol, risperidone and olanzapine.

The present study was conducted to characterize the binding of neurotransmitter receptors (dopamine D(2), serotonin 5-HT(2), histamine H(1), adrenaline alpha(1) and muscarine M(l) receptors) in the rat's brain after the oral administration of haloperidol, risperidone, and olanzapine. Haloperidol at 1 and 3 mg/kg displayed significant activity to bind the D(2) receptor (increase in the Kd value for [(3)H]raclopride binding) in the corpus striatum with little change in the activity toward the 5-HT(2) receptor (binding parameters for [(3)H]ketanserin). In contrast, risperidone (0.1-3 mg/kg) showed roughly 30 times more affinity for the 5-HT(2) receptor than D(2) receptor. Also, olanzapine (1-10 mg/kg) was most active toward the H(1) receptor in the cerebral cortex, corpus striatum, and hippocampus, was less active in binding 5-HT(2) and D(2) receptors, and showed the least affinity for alpha(1) and M(1) receptors. In conclusion, haloperidol and risperidone administered orally selectively bind D(2) and 5-HT(2) receptors, respectively, in the rat brain, while olanzapine binds H(1), 5-HT(2), and D(2) receptors more than alpha(1) and M(1) receptors.

Relationship between brain serotonin transporter binding, plasma concentration and behavioural effect of selective serotonin reuptake inhibitors.

1. The present study was undertaken to characterise the relationship between in vivo brain serotonin transporter (SERT) binding, plasma concentration and pharmacological effect of selective serotonin reuptake inhibitors (SSRIs) in mice. Oral administration of fluvoxamine, fluoxetine, paroxetine and sertraline at pharmacologically relevant doses exerted dose- and time-dependent binding activity of brain SERT as revealed by significant increases in KD for specific [3H]paroxetine binding, and the in vivo SERT-binding potency was in the order of paroxetine>>fluoxetine, sertraline>fluvoxamine. 2. The time courses of brain SERT binding by SSRIs in mice were mostly in parallel to those of their plasma concentrations. Also, norfluoxetine (active metabolite) has been suggested to contribute largely to the long-lasting binding activity of brain SERT after the fluoxetine administration. 3. Oral administration of each SSRI suppressed significantly the marble-burying behaviour with no change in locomotor activity in mice, and the extent and time course of suppression agreed well with those of brain SERT binding. Thus, the pharmacological potencies of SSRIs in the attenuation of marble-burying behaviour correlated significantly with their brain SERT binding activities. 4. In conclusion, the present study has provided the first in vivo evidences to support that fluvoxamine, fluoxetine, paroxetine and sertraline orally administered bind to the pharmacologically relevant brain SERT in mice and that their SERT-binding characteristics is closely associated with the pharmacokinetics and inhibition of marble-burying behaviour.

Effects of continuous administration of paroxetine on ligand binding site and expression of serotonin transporter protein in mouse brain.

Selective serotonin reuptake inhibitors (SSRIs), such as paroxetine, are utilized in the treatment of depression and anxiety disorders. Although SSRIs potently interfere with the activity of brain serotonin transporter (SERT) after acute treatment, clinical improvement of psychiatric diseases is observed only after the repeated administration for several weeks (2-6 weeks). The present study was undertaken to investigate the effects of continuous administration of paroxetine on specific [3H]paroxetine binding sites and expression of SERT protein in mouse brain. Mice continuously and subcutaneously received paroxetine at doses of 2.67 or 13.3 mumol/kg/day for 21 days by using osmotic minipumps, and the steady-state plasma drug levels were within the range of reported concentrations in the clinical therapy. Continuous administration of paroxetine at theses doses produced significant (25-46%) reduction of [3H]paroxetine binding in each brain region (cerebral cortex, striatum, hippocampus, thalamus, midbrain) of mice. In Western blot analysis, expression levels of SERT protein in the thalamus and midbrain of mice were significantly (51% and 61%, respectively) decreased on day 21 after the implantation of minipumps at the higher dose. In conclusion, this study has firstly shown that continuous administration of paroxetine induces significant reduction of not only ligand binding sites of SERT but the protein expression level in mouse brain. Such down-regulation of SERT may partly underlie the therapeutic effect of long-term treatment with SSRIs in human.

Discovery of GSK2795039, a Novel Small Molecule NADPH Oxidase 2 Inhibitor.

AIMS: The NADPH oxidase (NOX) family of enzymes catalyzes the formation of reactive oxygen species (ROS). NOX enzymes not only have a key role in a variety of physiological processes but also contribute to oxidative stress in certain disease states. To date, while numerous small molecule inhibitors have been reported (in particular for NOX2), none have demonstrated inhibitory activity in vivo. As such, there is a need for the identification of improved NOX inhibitors to enable further evaluation of the biological functions of NOX enzymes in vivo as well as the therapeutic potential of NOX inhibition. In this study, both the in vitro and in vivo pharmacological profiles of GSK2795039, a novel NOX2 inhibitor, were characterized in comparison with other published NOX inhibitors. RESULTS: GSK2795039 inhibited both the formation of ROS and the utilization of the enzyme substrates, NADPH and oxygen, in a variety of semirecombinant cell-free and cell-based NOX2 assays. It inhibited NOX2 in an NADPH competitive manner and was selective over other NOX isoforms, xanthine oxidase, and endothelial nitric oxide synthase enzymes. Following systemic administration in mice, GSK2795039 abolished the production of ROS by activated NOX2 enzyme in a paw inflammation model. Furthermore, GSK2795039 showed activity in a murine model of acute pancreatitis, reducing the levels of serum amylase triggered by systemic injection of cerulein. INNOVATION AND CONCLUSIONS: GSK2795039 is a novel NOX2 inhibitor that is the first small molecule to demonstrate inhibition of the NOX2 enzyme in vivo.

Cyclopropane-based conformational restriction of histamine. (1S,2S)-2-(2-aminoethyl)-1-(1H-imidazol-4-yl)cyclopropane, a highly selective agonist for the histamine H3 receptor, having a cis-cyclopropane structure.

A series of cyclopropane-based conformationally restricted analogues of histamine, the "folded" cis-analogues, i.e., (1S,2R)-2-(aminomethyl)-1-(1H-imidazol-4-yl)cyclopropane (11), (1S,2S)-2-(2-aminoethyl)-1-(1H-imidazol-4-yl)cyclopropane (13), and their enantiomers ent-11 and ent-13, and the "extended" trans-analogues, i.e., (1R,2R)-2-(aminomethyl)-1-(1H-imidazol-4-yl)cyclopropane (12) and its enantiomer ent-12, were designed as histamine H(3) receptor agonists. These target compounds were synthesized from the versatile chiral cyclopropane units, (1S,2R)- and (1R,2R)-2-(tert-butyldiphenylsilyloxy)methyl-1-formylcyclopropane (14 and 15, respectively) or their enantiomers ent-14 and ent-15. Among the conformationally restricted analogues, the "folded" analogue 13 (AEIC) having the cis-cyclopropane structure was identified as a potent H(3) receptor agonist, which showed a significant binding affinity (K(i) = 1.31 +/- 0.16 nM) and had an agonist effect (EC(50) value of 10 +/- 3 nM) on the receptor. This compound owes its importance to being the first highly selective H(3) receptor agonist to have virtually no effect on the H(4) subtype receptor. These studies showed that the cis-cyclopropane structure is very effective in the conformational restriction of histamine to improve the specific binding to the histamine H(3) receptor.

In vivo identification and characterization of binding sites for selective serotonin reuptake inhibitors in mouse brain.

The present study was undertaken to identify and characterize in vivo binding sites of selective serotonin reuptake inhibitors (SSRIs) in the mouse brain by using [3H]paroxetine as radioligand. Relatively higher concentration of [3H]paroxetine was detected in the whole brain (minus cerebellum) than in the plasma of mice after the i.v. injection of the radioligand, and the half-life (t1/2) of elimination was much slower. The in vivo specific [3H]paroxetine binding in the mouse brain after the i.v. injection was defined as the difference of particulate-bound radioactivity between the whole brain and cerebellum, and it was dose-dependently attenuated by oral or intraperitoneal administration of fluoxetine (8.68-116 micromol/kg). Furthermore, oral administration of fluvoxamine, fluoxetine, paroxetine and sertraline at the pharmacologically relevant doses reduced significantly (25-94%) in vivo specific [3H]paroxetine binding in the cerebral cortex, striatum, hippocampus, thalamus and midbrain of mice, and their significant decreases were observed up to at least 8 h (fluvoxamine), 24 h (fluoxetine), and 12 h (paroxetine and sertraline) later. The value of area under the curve (AUC) for decrease in [3H]paroxetine binding vs. time in each brain region was largest for fluoxetine among these SSRIs, due to the relatively longer-lasting occupation of brain serotonin transporter. The AUC value in mouse brain after oral administration of each SSRI was 1.2-3.2 times greater in the thalamus and midbrain than in the cerebral cortex, striatum and hippocampus. Thus, the present study has revealed that [3H]paroxetine may be a suitable radioligand for in vivo characterization of brain binding sites and pharmacological effects of SSRIs.