Orexin 2 receptor-selective agonist danavorexton (TAK-925) promotes wakefulness in non-human primates and healthy individuals.

The orexin 2 receptor-selective agonist danavorexton (TAK-925) has been shown to produce wake-promoting effects in wild-type mice, narcolepsy-model mice, and individuals with narcolepsy type 1 and type 2. Here, we report wake-promoting effects of danavorexton in non-human primates and healthy men during their sleep phase. Electroencephalogram analyses revealed that subcutaneous administration of danavorexton significantly increased wakefulness in common marmosets (p < 0.05 at 0.1 mg kg-1 , and p < 0.001 at 1 mg kg-1 and 10 mg kg-1 ) and cynomolgus monkeys (p ≤ 0.05 at 1 mg kg-1 and 3 mg kg-1 ). In a phase 1b crossover, randomized, double-blind, placebo-controlled and active-controlled study in sleep-deprived healthy participants (ClinicalTrials.gov identifier: NCT03522506), modafinil 300 mg (used to demonstrate assay sensitivity) and continuous infusion of danavorexton 44 mg and danavorexton 112 mg showed statistically superior wake-promoting effects to placebo (n = 18). Measured using the Maintenance of Wakefulness Test, mean (standard deviation) sleep latencies during infusion of danavorexton 44 mg, danavorexton 112 mg and placebo were 21.4 (8.9), 31.8 (3.2) and 9.2 (6.4) min, respectively. Least-squares mean difference from placebo in average sleep latency was 16.8 min with danavorexton 44 mg and 30.2 min with danavorexton 112 mg (both p < 0.001). Karolinska Sleepiness Scale scores were statistically significantly lower (indicating decreased sleepiness) for participants receiving danavorexton than for those receiving placebo during infusion (danavorexton 44 mg, p = 0.010; danavorexton 112 mg, p < 0.001). Together, these results indicate that an orexin 2 receptor agonist increases wakefulness in non-human primates and healthy individuals during their sleep phase.

Orexin 2 receptor-selective agonist danavorexton improves narcolepsy phenotype in a mouse model and in human patients.

Narcolepsy type 1 (NT1) is a sleep disorder caused by a loss of orexinergic neurons. Narcolepsy type 2 (NT2) is heterogeneous; affected individuals typically have normal orexin levels. Following evaluation in mice, the effects of the orexin 2 receptor (OX2R)-selective agonist danavorexton were evaluated in single- and multiple-rising-dose studies in healthy adults, and in individuals with NT1 and NT2. In orexin/ataxin-3 narcolepsy mice, danavorexton reduced sleep/wakefulness fragmentation and cataplexy-like episodes during the active phase. In humans, danavorexton administered intravenously was well tolerated and was associated with marked improvements in sleep latency in both NT1 and NT2. In individuals with NT1, danavorexton dose-dependently increased sleep latency in the Maintenance of Wakefulness Test, up to the ceiling effect of 40 min, in both the single- and multiple-rising-dose studies. These findings indicate that OX2Rs remain functional despite long-term orexin loss in NT1. OX2R-selective agonists are a promising treatment for both NT1 and NT2.

Safety and efficacy of pioglitazone for the delay of cognitive impairment in people at risk of Alzheimer's disease (TOMMORROW): a prognostic biomarker study and a phase 3, randomised, double-blind, placebo-controlled trial.

BACKGROUND: The identification of people at risk of cognitive impairment is essential for improving recruitment in secondary prevention trials of Alzheimer's disease. We aimed to test and qualify a biomarker risk assignment algorithm (BRAA) to identify participants at risk of developing mild cognitive impairment due to Alzheimer's disease within 5 years, and to evaluate the safety and efficacy of low-dose pioglitazone to delay onset of mild cognitive impairment in these at-risk participants. METHODS: In this phase 3, multicentre, randomised, double-blind, placebo-controlled, parallel-group study, we enrolled cognitively healthy, community living participants aged 65-83 years from 57 academic affiliated and private research clinics in Australia, Germany, Switzerland, the UK, and the USA. By use of the BRAA, participants were grouped as high risk or low risk. Participants at high risk were randomly assigned 1:1 to receive oral pioglitazone (0·8 mg/day sustained release) or placebo, and all low-risk participants received placebo. Study investigators, site staff, sponsor personnel, and study participants were masked to genotype, risk assignment, and treatment assignment. The planned study duration was the time to accumulate 202 events of mild cognitive impairment due to Alzheimer's disease in White participants who were at high risk (the population on whom the genetic analyses that informed the BRAA development was done). Primary endpoints were time-to-event comparisons between participants at high risk and low risk given placebo (for the BRAA objective), and between participants at high risk given pioglitazone or placebo (for the efficacy objective). The primary analysis included all participants who were randomly assigned, received at least one dose of study drug, and had at least one valid post-baseline visit, with significance set at p=0·01. The safety analysis included all participants who were randomly assigned and received at least one dose of study medication. An efficacy futility analysis was planned for when approximately 33% of the anticipated events occurred in the high-risk, White, non-Hispanic or Latino group. This trial is registered with ClinicalTrials.gov, NCT01931566. FINDINGS: Between Aug 28, 2013, and Dec 21, 2015, we enrolled 3494 participants (3061 at high risk and 433 at low risk). Of those participants, 1545 were randomly assigned to pioglitazone and 1516 to placebo. 1104 participants discontinued treatment (464 assigned to the pioglitazone group, 501 in the placebo high risk group, and 139 in the placebo low risk group). 3399 participants had at least one dose of study drug or placebo and at least one post-baseline follow-up visit, and were included in the efficacy analysis. 3465 participants were included in the safety analysis (1531 assigned to the pioglitazone group, 1507 in the placebo high risk group, and 427 in the placebo low risk group). In the full analysis set, 46 (3·3%) of 1406 participants at high risk given placebo had mild cognitive impairment due to Alzheimer's disease, versus four (1·0%) of 402 participants at low risk given placebo (hazard ratio 3·26, 99% CI 0·85-12·45; p=0·023). 39 (2·7%) of 1430 participants at high risk given pioglitazone had mild cognitive impairment, versus 46 (3·3%) of 1406 participants at high risk given placebo (hazard ratio 0·80, 99% CI 0·45-1·40; p=0·307). In the safety analysis set, seven (0·5%) of 1531 participants at high risk given pioglitazone died versus 21 (1·4%) of 1507 participants at high risk given placebo. There were no other notable differences in adverse events between groups. The study was terminated in January, 2018, after failing to meet the non-futility threshold. INTERPRETATION: Pioglitazone did not delay the onset of mild cognitive impairment. The biomarker algorithm demonstrated a 3 times enrichment of events in the high risk placebo group compared with the low risk placebo group, but did not reach the pre-specified significance threshold. Because we did not complete the study as planned, findings can only be considered exploratory. The conduct of this study could prove useful to future clinical development strategies for Alzheimer's disease prevention studies. FUNDING: Takeda and Zinfandel.

Folate metabolism biomarkers from two randomised placebo-controlled clinical studies with paroxetine and venlafaxine.

OBJECTIVES: Based on the hypothesis of a role for folate and vitamin B12 in major depressive disorders (MDD), we aimed at validating the association between folate pathway biomarkers and depression or antidepressant response in clinical trial populations. METHODS: We investigated serum levels erythrocyte folate and serum levels of homocysteine, vitamin B12, and folate as disease and response biomarkers for MDD in two independent randomised, placebo-controlled clinical trials, where paroxetine or venlafaxine were used as active controls, for a total of 881 patients. RESULTS: Significant but weak correlations between depression severity and biomarker levels could be detected in the paroxetine study for serum folate and vitamin B12, with no correlations for any biomarker in the venlafaxine study. Besides a weak association for erythrocyte folate in the venlafaxine study, no significant associations were observed between treatment response and pre-treatment levels of any of the biomarkers tested. CONCLUSIONS: Notwithstanding the relatively large number of patients tested, we did not find consistent associations between folate biomarkers and MDD severity, or response to paroxetine and venlafaxine. Our results may be related to the particular study design or clinical population; however, our findings do not support the hypothesis of a dysfunction of one-carbon metabolism in MDD.

Neurokinin-1 antagonist orvepitant for EGFRI-induced pruritus in patients with cancer: a randomised, placebo-controlled phase II trial.

OBJECTIVE: To evaluate the efficacy of orvepitant (10 or 30 mg given once daily, orally for 4 weeks), a neurokinin-1 receptor antagonist, compared with placebo in reducing the intensity of epidermal growth factor receptor inhibitor (EGFRI)-induced intense pruritus. DESIGN: Randomised, double-blind, placebo-controlled clinical trial. SETTING: 15 hospitals in Italy and five hospitals in the UK. PARTICIPANTS: 44 patients aged ≥18 years receiving an EGFRI for a histologically confirmed malignant solid tumour and experiencing moderate or intense pruritus after EGFRI treatment. INTERVENTION: 30 or 10 mg orvepitant or placebo tablets once daily for 4 weeks (randomised 1:1:1). PRIMARY AND SECONDARY OUTCOME MEASURES: The primary endpoint was change from baseline in mean patient-recorded numerical rating scale (NRS) score (over the last three recordings) at week 4. Secondary outcome measures were NRS score, verbal rating scale score, Skindex-16 and Leeds Sleep Evaluation Questionnaire at each study visit (baseline, weeks 1, 4, 8); rescue medication use; EGFRI dose reduction; and study withdrawal because of intense uncontrolled pruritus. RESULTS: The trial was terminated early because of recruitment challenges; only 44 of the planned 90 patients were randomised. All patients were analysed for efficacy and safety. Mean NRS score change from baseline to week 4 was -2.78 (SD: 2.64) points in the 30 mg group, -3.04 (SD: 3.06) points in the 10 mg group and -3.21 (SD: 1.77) points in the placebo group; the difference between orvepitant and placebo was not statistically significant. No safety signal was detected. Adverse events related to orvepitant (asthenia, dizziness, dry mouth, hyperhidrosis) were all of mild or moderate severity. CONCLUSIONS: Orvepitant was safe and well tolerated. No difference in NRS score between the orvepitant and placebo groups was observed at the week 4 primary endpoint. A number of explanations for this outcome are possible. TRIAL REGISTRATION NUMBER: EudraCT2013-002763-25.

Biomarkers for response in major depression: comparing paroxetine and venlafaxine from two randomised placebo-controlled clinical studies.

The identification of biomarkers of response might speed drug development and set the premises to assist clinical practice in psychiatry. In this work, we evaluated a panel of peripheral biomarkers (including IL-6, IL-10, TNF-α, TNFRII, BDNF, CRP, MMP9 and PAI1) in depressed patients receiving paroxetine, venlafaxine, or placebo. Samples were obtained from two randomised placebo-controlled studies evaluating the efficacy and tolerability of a novel drug candidate, using either paroxetine or venlafaxine as active comparators. In both studies, the biomarker candidates were analysed in plasma collected at randomization and after 10 weeks of treatment with either placebo or active comparator (for a total of 106 and 108 subjects in the paroxetine and venlafaxine study, respectively). Data were obtained by multiplexing sandwich-ELISA system. Data were subjected to statistical analysis to assess their correlation with baseline severity and with response outcome. Increases in biomarker levels were correlated with reduction in depression severity for TNF-α, IL-6 IL-10 and CRP. Response to paroxetine treatment correlated with baseline IL-10, IL-6 and TNF-α levels, with the strongest signal being observed in males. In the venlafaxine study, a correlation was observed only between CRP level at randomisation and response, suggesting differences between the two active treatments and the two studies. Our investigations suggest that a combination of pro- and anti-inflammatory cytokines may predict response outcome in patients treated with paroxetine. The potential for IL-10, IL-6 and TNF-α as response biomarkers for a wider range of antidepressants warrants further investigations in clinical trials with other monoamine reuptake inhibitors.

Strategies to Address Challenges in Neuroscience Drug Discovery and Development.

The paucity of novel drugs for neuropsychiatric indications contrasts with the remarkable recent advances in neuroscience research. We have identified 5 challenges the field needs to address and recommend potential solutions. First, we need to drive discovery efforts based on human data. Second, we need to think more carefully about animal models, embracing them as tools to test pathophysiological alterations. Third, we need to develop strategies to select more homogenous groups of patients in our clinical trials. Fourth, we need to develop and validate translational biomarkers, which can be used for pharmacodynamic assessments as well as for patient selection. Fifth, we need to adopt more reliable and objective measures to capture clinical efficacy. The tools that will allow these solutions to be implemented may already be in place but not routinely adopted or are still being developed. Overall, a change in mindset to adopt science- and data-driven paths is needed.

The Italian autism network (ITAN): a resource for molecular genetics and biomarker investigations.

BACKGROUND: A substantial genetic component accounts for Autism Spectrum Disorders (ASD) aetiology, with some rare and common genetic risk factors recently identified. Large collections of DNAs from thoroughly characterized ASD families are an essential step to confirm genetic risk factors, identify new variants and investigate genotype-phenotype correlations. The Italian Autism Network aimed at constituting a clinical database and a biorepository of samples derived from ASD subjects and first-degree relatives extensively and consistently characterized by child psychiatry centers in Italy. METHODS: The study was approved by the ethical committee of the University of Verona, the coordinating site, and by the local ethical committees of each recruiting site. Certified staff was specifically trained at each site for the overall study conduct, for clinical protocol administration and handling of biological material. A centralized database was developed to collect clinical assessment and medical records from each recruiting site. Children were eligible for recruitment based on the following inclusion criteria: age 4-18 years, at least one parent or legal guardian giving voluntary written consent, meeting DSM-IV criteria for Autistic Disorder or Asperger's Disorder or Pervasive Developmental Disorder NOS. Affected individuals were assessed by full psychiatric, neurological and physical examination, evaluation with ADI-R and ADOS scales, cognitive assessment with Wechsler Intelligence Scale for Children or Preschool and Primary, Leiter International Performance Scale or Griffiths Mental Developmental Scale. Additional evaluations included language assessment, the Krug Asperger's Disorder Index, and instrumental examination such as EEG and structural MRI. DNA, RNA and plasma were collected from eligible individuals and relatives. A central laboratory was established to host the biorepository, perform DNA and RNA extraction and lymphocytes immortalisation. DISCUSSION: The study has led to an extensive collection of biological samples associated with standardised clinical assessments from a network of expert clinicians and psychologists. Eighteen sites have received ADI/ADOS training, thirteen of which have been actively recruiting. The clinical database currently includes information on 812 individuals from 249 families, and the biorepository has samples for 98% of the subjects. This effort has generated a highly valuable resource for conducting clinical and genetic research of ASD, amenable to further expansion.

Alpha6-Containing Nicotinic Acetylcholine Receptors Mediate Nicotine-Induced Structural Plasticity in Mouse and Human iPSC-Derived Dopaminergic Neurons.

Midbrain dopamine (DA) neurons are considered a critical substrate for the reinforcing and sensitizing effects of nicotine and tobacco dependence. While the role of the α4 and ß2 subunit containing nicotinic acetylcholine receptors (α4ß2∗nAChRs) in mediating nicotine effects on DA release and DA neuron activity has been widely explored, less information is available on their role in the morphological adaptation of the DA system to nicotine, eventually leading to dysfunctional behaviors observed in nicotine dependence. In particular, no information is available on the role of α6∗nAChRs in nicotine-induced structural plasticity in rodents and no direct evidence exists regarding the occurrence of structural plasticity in human DA neurons exposed to nicotine. To approach this problem, we used two parallel in vitro systems, mouse primary DA neuron cultures from E12.5 embryos and human DA neurons differentiated from induced pluripotent stem cells (iPSCs) of healthy donors, identified using TH+ immunoreactivity. In both systems, nicotine 1-10 µM produced a dose-dependent increase of maximal dendrite length, number of primary dendrites, and soma size when measured after 3 days in culture. These effects were blocked by pretreatments with the α6∗nAChR antagonists α-conotoxin MII and α-conotoxin PIA, as well as by the α4ß2nAChR antagonist dihydro-ß-erythroidine (DHßE) in both mouse and human DA neurons. Nicotine was also ineffective when the primary DA neurons were obtained from null mutant mice for either the α6 subunit or both the α4 and α6 subunits of nAChR. When pregnant mice were exposed to nicotine from gestational day 15, structural plasticity was also observed in the midbrain DA neurons of postnatal day 1 offspring only in wild-type mice and not in both null mutant mice. This study confirmed the critical role of α4α6∗nAChRs in mediating nicotine-induced structural plasticity in both mouse and human DA neurons, supporting the translational relevance of neurons differentiated from human iPSCs for pharmacological studies.

Neurokinin-1 receptor antagonist orvepitant is an effective inhibitor of itch-associated response in a Mongolian gerbil model of scratching behaviour.

Data suggest that substance P could play an important role in pruritus, and therefore, blockade of the neurokinin (NK)-1 receptor might be antipruritic. Thus, we explored in the Mongolian gerbil the effect on scratching behaviour, induced by intra-dermal injection of the NK-1 receptor-specific agonist GR73632, of oral administration of the NK-1 receptor antagonist orvepitant. Orvepitant at all doses tested (0.1-10 mg/kg p.o.) produced a profound inhibition of GR73632 (30 nmol i.d.) induced hindlimb scratching; the minimum effective dose of orvepitant in this model was identified as ≤0.1 mg/kg. The data generated supported the proposition that the antipruritic potential of orvepitant should be evaluated in clinical trials.

Evaluation of antidepressant properties of the p38 MAP kinase inhibitor losmapimod (GW856553) in Major Depressive Disorder: Results from two randomised, placebo-controlled, double-blind, multicentre studies using a Bayesian approach.

Pro-inflammatory cytokines (PICs) may play important pathophysiological roles in some forms of Major Depressive Disorder (MDD). The p38 MAPK inhibitor losmapimod (GW856553) attenuates the pro-inflammatory response in humans by reducing PIC production. Losmapimod (7.5 mg BD) was administered for 6 weeks in two randomised, placebo-controlled trials in subjects with MDD enriched with symptoms of loss of energy/interest and psychomotor retardation (Studies 574 and 009). Primary efficacy endpoints were the Bech 6-item depression subscale of the HAMD-17 (the 'Bech,') for Study 009; and the Bech, Inventory of Depressive Symptomatology-Clinician Rated (IDS-C), HAMD-17, and Quick Inventory of Depressive Symptomatology (self-rated) (QIDS-SR) for Study 574. Key cytokine biomarker levels were also measured. Study 574 (n=24) was terminated prematurely in light of emerging data from an internal study in rheumatoid arthritis. Efficacy results available at termination favoured losmapimod (Bech, 6 weeks: endpoint drug vs. placebo difference = -4.10; 95% CI, -7.36, -0.83; p=0.017). A subsequent study, Study 009 (n=128), designed using a Bayesian approach based on a prior derived from Study 574, showed no advantage for losmapimod (Bech, 6 weeks: endpoint drug vs. placebo difference = 1.11; 95% credible interval, -0.22, 2.50). Biomarker data showed no significant changes. In conclusion 7.5 mg BID losmapimod was not effective in MDD.

Characterising the plasma-target occupancy relationship of the neurokinin antagonist GSK1144814 with PET.

GSK1144814 is a potent, insurmountable antagonist at human NK1 and NK3 receptors. Understanding the relationship between plasma pharmacokinetics and receptor occupancy in the human brain, was crucial for dose selection in future clinical studies. GSK1144814 occupancy data were acquired in parallel with the first-time-in-human safety and tolerability study. [¹¹C]GR-205171 a selective NK1 receptor PET ligand was used to estimate NK1 occupancy at several time-points following single dose administration of GSK1144814. The time-plasma concentration-occupancy relationship post-single dose administration was assessed, and used to predict the plasma concentration-occupancy relationship following repeat dose administration. Repeat dose predictions were tested in a subsequent cohort of subjects examined following approximately 7 and 14 days dosing with GSK1144814. GSK1144814 was shown to demonstrate a dose-dependent occupancy of the NK1 receptor with an estimated in vivo EC50~0.9 ng/mL in the human brain. A direct relationship was seen between the GSK1144814 plasma concentration and its occupancy of the brain NK1 receptor, indicating that in future clinical trials the occupancy of brain receptors can be accurately inferred from the measured plasma concentration. Our data provided support for the further progression of this compound and have optimised the likely therapeutic dose range.

Efficacy of vestipitant, a neurokinin-1 receptor antagonist, in primary insomnia.

STUDY OBJECTIVES: Investigate the hypnotic effects of repeated doses of neurokinin-1 receptor antagonist, vestipitant, in primary insomnia. DESIGN: Randomized, double-blind, placebo-controlled 28-day parallel-group study. SETTING: Eleven sleep centers in Germany. PATIENTS: One hundred sixty-one patients with primary insomnia. INTERVENTIONS: Patients received vestipitant (15 mg) or placebo for 28 days; 2-night polysomnographic assessment occurred on nights 1/2 and 27/28. MEASUREMENTS AND RESULTS: Wake after sleep onset (WASO) was improved on nights 1/2 and 27/28 (ratio, vestipitant versus placebo [95% confidence interval]: 0.76 [0.65, 0.90], P = 0.001 and 0.79 [0.65, 0.96], P = 0.02, respectively), demonstrating maintenance of the effect following repeated dosing. Latency to persistent sleep was shorter with vestipitant on nights 1/2 (P = 0.0006 versus placebo), but not on nights 27/28. Total sleep time (TST) improved with vestipitant (nights 1/2: P < 0.0001, nights 27/28: P = 0.02 versus placebo). Next-day cognitive function tests demonstrated no residual effects of vestipitant (P > 0.05 versus placebo). Adverse events (AEs) occurred in 25% of vestipitant patients versus 22% for placebo. Headache was the most common AE (8% of vestipitant patients versus 9% for placebo). CONCLUSIONS: Vestipitant improved sleep maintenance in patients with primary insomnia, with no associated next-day cognitive impairment. The effects on wake after sleep onset and total sleep time were maintained following repeated dosing.

Identification, biological characterization and pharmacophoric analysis of a new potent and selective NK1 receptor antagonist clinical candidate.

The last two decades have provided a large weight of preclinical data implicating the neurokinin-1 receptor (NK1) and its cognate ligand substance P (SP) in a broad range of both central and peripheral disease conditions. However, to date, only the NK1 receptor antagonist aprepitant has been approved as a therapeutic and this is to prevent chemotherapy-induced nausea & vomiting (CINV). The belief remained that the full therapeutic potential of NK1 receptor antagonists had yet to be realized; therefore clinical evidence that NK1 receptor antagonists may be effective in major depression disorder, resulted in a significant further investment in discovering novel CNS penetrant druggable NK1 receptor antagonists to address this condition. At GlaxoSmithKline after the discovery of casopitant, that went on to demonstrate efficacy as a novel antidepressant in the clinic, additional novel analogues of this NK1 receptor antagonist were designed to further enhance its drug developability characteristics. Herein, we therefore describe the discovery process and the vivo pharmacological and pharmacokinetic profile of the new NK1 receptor antagonist 3a (also called orvepitant), selected as clinical candidate and further progressed into clinical studies for major depressive disorder. Moreover, molecular modeling studies enabled us to improve the pharmacophore model of the NK1 receptor antagonists with the identification of a region able to accommodate a variety of heterocycle moieties.

Why receptor reserve matters for neurokinin1 (NK1) receptor antagonists.

The difference in location between the receptor occupancy curve of an agonist and its functional response has been described as receptor reserve. This "reserve" for a specific receptor has been found to differ from tissue to tissue and between agonists acting on the same tissue. Recently, two structurally different neurokinin 1 (NK1) receptor antagonists were taken into human and both were tested as antidepressants and for insomnia. Vestipitant and Casopitant both have high affinity for the human NK1 receptor (pKi = 9.4 and 10.2, respectively). In human, at the chosen clinical doses, receptor occupancy was measured in the frontal cortex, at 24 hours post administration, as ∼90% for vestipitant (15 mg) and ∼100% for casopitant (30 mg). In patients with moderate to severe major depression, vestipitant given at 15 mg for 8 weeks showed no statistical significant benefit as measured by change in baseline in HAM-D total score; whereas casopitant at 80 mg achieved statistically significant improvement versus placebo at week 8 (LOCF HAMD17 = -2.7, p = 0.023). A lower dose of 30 mg showed a clear but not significant separation from placebo. However, in acute studies in insomnia, both vestipitant and casopitant at 15 mg and 30 mg, respectively, significantly reduced latency to persistent sleep, wakenings after sleep onset and increased total sleep time by similar amounts. These clinical results suggest that for major depression the receptor occupancy of an NK1 antagonist needs to be very high (almost 100%), whereas, for insomnia a lower occupation is sufficient to give clinical effect.

Full central neurokinin-1 receptor blockade is required for efficacy in depression: evidence from orvepitant clinical studies.

Full, persistent blockade of central neurokinin-1 (NK1) receptors may be a potential antidepressant mechanism. The selective NK1 antagonist orvepitant (GW823296) was used to test this hypothesis. A preliminary positron emission tomography study in eight male volunteers drove dose selection for two randomized six week studies in patients with major depressive disorder (MDD). Displacement of central [(11)C]GR205171 binding indicated that oral orvepitant doses of 30-60 mg/day provided >99% receptor occupancy for ≥24 h. Studies 733 and 833 randomized patients with MDD and 17-item Hamilton Depression Rating Scale (HAM-D)≥22 to double-blind treatment with orvepitant 30 mg/day, orvepitant 60 mg/day or placebo (1:1:1). Primary outcome measure was change from baseline in 17-item HAM-D total score at Week 6 analyzed using mixed models repeated measures. Study 733 (n=328) demonstrated efficacy on the primary endpoint (estimated drug-placebo differences of 30 mg: -2.41, 95% confidence interval (CI) (-4.50 to -0.31) p=0.0245; 60 mg: -2.86, 95% CI (-4.97 to -0.75) p=0.0082). Study 833 (n=345) did not show significance (estimated drug-placebo differences of 30 mg: -1.67, 95% CI (-3.73 to 0.39) p=0.1122; 60 mg: -0.76, 95% CI (-2.85 to 1.32) p=0.4713). The results support the hypothesis that full, long lasting blockade of central NK1 receptors may be an efficacious mechanism for the treatment of MDD.

The orexin antagonist SB-649868 promotes and maintains sleep in men with primary insomnia.

STUDY OBJECTIVES: To assess the acute effects of SB-649868 in male subjects with Primary Insomnia with regard to (1) objective and subjective sleep parameters, (2) safety and tolerability, (3) next-day residual effects. DESIGN: Multicenter, randomized, double-blind, placebo-controlled crossover study using a complete set of Williams orthogonal Latin Squares SETTING: 9 sleep centers in Germany PATIENTS: 52 male subjects with a diagnosis of primary insomnia (difficulty in sleep initiation and maintenance) confirmed by polysomnography INTERVENTIONS: SB-649868 (10, 30, 60 mg) and placebo administered after dinner 90 minutes before bedtime MEASUREMENTS AND RESULTS: Sleep effects assessed by polysomnography during 2 consecutive nights and by sleep questionnaires completed by subjects after each night at the sleep laboratory. Safety and tolerability were assessed by adverse events collection, electrocardiogram (ECG), vital signs, laboratory tests. Next-day residual effects were assessed by Digit Symbol Substitution Test, and modified Verbal Learning Memory Test administered at "lights on" after night 2. SB-649868 significantly reduced latency to persistent sleep, wake after sleep onset (WASO), and increased total sleep time (TST) compared to placebo. A dose-dependent effect was observed. A dose-dependent increase in absolute and percent REM sleep and reduction in REM sleep latency was observed mainly at the 60-mg dose. SB-649868 was well tolerated with inconsistent next day residual effects. SB-649868 sleep effects were correlated with SB-649868 circulating levels. CONCLUSION: The data demonstrate the sleep-promoting properties of the orexin antagonist SB-649868 in male patients with insomnia.

The association of rs4307059 and rs35678 markers with autism spectrum disorders is replicated in Italian families.

OBJECTIVE: The objective of this study was to replicate an association study on a newly collected Italian autism spectrum disorder (ASD) cohort by studying the genetic markers associated with ASDs from recent genome-wide and candidate gene association studies. METHODS: We have genotyped 746 individuals from 227 families of the Italian Autism Network using allelic discrimination TaqMan assays for seven common single-nucleotide polymorphisms: rs2292813 (SLC25A12 gene), rs35678 (ATP2B2 gene), rs4307059 (between CDH9 and CDH10 genes), rs10513025 (between SEMA5A and TAS2R1 genes), rs6872664 (PITX1 gene), rs1861972 (EN2 gene), and rs4141463 (MACROD2 gene). A family-based association study was conducted. RESULTS: A significant association was found for two of seven markers: rs4307059 T allele (odds ratio: 1.758, SE=0.236; P-value=0.017) and rs35678 TC genotype (odds ratio: 0.528, SE=0.199; P-value=0.0013). CONCLUSION: A preferential allele transmission of two markers located at loci previously associated with social and verbal communication skill has been confirmed in patients of a new ASD family sample.

Efficacy, safety, and tolerability of a triple reuptake inhibitor GSK372475 in the treatment of patients with major depressive disorder: two randomized, placebo- and active-controlled clinical trials.

GSK372475 is a triple reuptake inhibitor with approximately equipotent inhibition of serotonin, norepinephrine, and dopamine transporters. Two randomized, placebo- and active-controlled, double-blind studies examined the efficacy and safety of GSK372475 in outpatients (aged 18-64 years) with a diagnosis of major depressive episode associated with major depressive disorder (MDD). Patients were randomized 1:1:1 to placebo, GSK372475 (1-2 mg/d), or active control (Study 1: venlafaxine XR 150-225 mg/d; Study 2: paroxetine 20-30 mg/d). GSK372475 did not significantly differ from placebo on any of the key efficacy endpoints (six-item Bech scale, IDS-Clinician Rated, MADRS) in either study. Both active controls demonstrated significant antidepressant activity compared with placebo on both primary and secondary endpoints. The most common adverse effects (AEs) with GSK372475 were dry mouth, headache, insomnia, and nausea. AEs were more frequent for GSK372475 versus placebo for sleep, anxiety-related, gastrointestinal, and tachycardia events. Increases in mean change from baseline in heart rate and sitting blood pressure were greater for GSK372475 than observed for either placebo or active control groups. Completion rates were lower for GSK372475 (49%, 58%) compared with placebo (67%, 74%), venlafaxine XR (63%), or paroxetine (77%). GSK372475 was neither efficacious nor well tolerated in patients with MDD in two 10-week studies.

Phase I studies on the safety, tolerability, pharmacokinetics and pharmacodynamics of SB-649868, a novel dual orexin receptor antagonist.

The orexin system plays a major role in the integration of metabolic and circadian influences that drive wakefulness. This paper describes initial Phase I trials of a novel dual orexin receptor antagonist SB-649868 that has demonstrated preclinical potential for treatment of sleep disorders. The trial designs included a single ascending dose escalation study (dose range: 10-80 mg in the fed and fasted states) and a multiple repeat dose study (dose range: 5-30 mg in the fed state) enrolling a total of 103 male volunteer subjects. SB-649868 was well tolerated at all doses in this study population, with mechanism-related adverse events (e.g. somnolence and fatigue) observed in a majority of subjects after 60 and 80 mg single doses. Although total drug exposure was similar in the fed and fasted states, the rate, but not the extent, of absorption increased in the fed state, resulting in an increased C(max). The typical estimated half-life of SB-649868 was 3-6 h - comparable with currently used hypnotic agents. Repeated administration of SB-649868 dose-dependently increased exposure to simvastatin (10 mg), suggesting CYP3A4 inhibition ranging from very mild (5 mg) to strong (30 mg). Evening dosing resulted in significant dose-dependent improvement in latency to persistent sleep, total sleep time and wake after sleep onset as measured by polysomnography. Next-morning testing did not detect evidence of residual cognitive effects. Results of these trials support further investigation of SB-649868 and other dual orexin receptor antagonists as potentially effective and well-tolerated treatments for patients with sleep disorders.