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Mevidalen (LY3154207) is a positive allosteric modulator of the dopamine D1 receptor that enhances the affinity of dopamine for the D1 receptor. The safety, tolerability, motor effects, and pharmacokinetics of mevidalen were studied in patients with Parkinson disease. Mevidalen or placebo was given once daily for 14 days to 2 cohorts of patients (cohort 1, 75 mg; cohort 2, titration from 15 to 75 mg). For both cohorts, the median time to maximum concentration for mevidalen plasma concentration was about 2 hours, the apparent steady-state clearance was 20-25 L/h, and mevidalen plasma concentrations were similar between the 1st and 14th administration in cohort 1, indicating minimal accumulation upon repeated dosing. Mevidalen was well tolerated, and most treatment-emergent adverse events were mild. Blood pressure and pulse rate increased when taking mevidalen, but there was considerable overlap with patients taking placebo, and vital signs normalized with repeated dosing. In the Movement Disorder Society-United Parkinson's Disease Rating Scale, all patients taking mevidalen showed a better motor examination sub-score on day 6 compared to only some patients in the placebo group. These data support examining mevidalen for symptomatic treatment of patients with Parkinson disease and Lewy body dementia.

Galcanezumab, a humanized monoclonal antibody targeting calcitonin gene-related peptide, was recently approved for migraine prophylaxis. The pharmacokinetic/pharmacodynamic (PK/PD) relationship between galcanezumab concentration and inhibition of capsaicin-induced dermal blood flow (CIDBF) was evaluated using first-in-human data following 6 single subcutaneous doses (1 to 600 mg) or multiple (4) 150-mg doses every 2 weeks in 7 cohorts (7 actively treated subjects and 2 placebo-treated healthy subjects). Galcanezumab pharmacokinetics were best described by a 1-compartment model with delayed first-order absorption/linear elimination. Apparent estimates (between-subject variability) of clearance, volume of distribution, absorption rate constant, and lag time were 0.0106 L/h (27%CV), 11.2 L (21%CV), 0.0192 h-1 (89%CV), and 0.202 hours, respectively. Estimated elimination half-life was about 30 days. An effect compartment link model described the concentration-effect relationship; estimated maximum inhibitory effect was 70.5%, and 50% maximum inhibitory effect concentration (IC50 ) was 1060 ng/mL. Galcanezumab showed dose- and concentration-dependent potent and durable inhibition of CIDBF. Simulated effect compartment concentrations were maintained above IC50 after 12 weeks of dosing. Near-maximal CIDBF inhibition occurred with 150 mg biweekly for 12 weeks lasting ≥24 weeks or with ≥30 mg every 2 weeks or 195 mg every 13 weeks. Quantitative modeling of galcanezumab PK/PD supported dose selection for the phase 2 proof-of-concept study.

Activation of the brain dopamine D1 receptor has attracted attention because of its promising role in neuropsychiatric diseases. Although efforts to develop D1 agonists have been challenging, a positive allosteric modulator (PAM), represents an attractive approach with potential better drug‐like properties. Phase 1 single‐ascending‐dose (SAD; NCT03616795) and multiple‐ascending‐dose (MAD; NCT02562768) studies with the D1PAM mevidalen (LY3154207) were conducted with healthy subjects. There were no treatment‐related serious adverse events (AEs) in these studies. In the SAD study, 25‐200 mg administered orally showed dose‐proportional pharmacokinetics (PK) and acute dose‐related increases in systolic blood pressure (SBP) and diastolic blood pressure DBP) and pulse rate at doses ≥ 75 mg. AE related to central activation were seen at doses ≥ 75 mg. At 25 and 75 mg, central penetration of mevidalen was confirmed by measurement of mevidalen in cerebrospinal fluid. In the MAD study, once‐daily doses of mevidalen at 15‐150 mg for 14 days showed dose‐proportional PK. Acute dose‐dependent increases in SBP, DBP, and PR were observed on initial administration, but with repeated dosing the effects diminished and returned toward baseline levels. Overall, these findings support further investigation of mevidalen as a potential treatment for a range of neuropsychiatric disorders.

Background This analysis characterizes the immunogenicity profile of galcanezumab, a humanized monoclonal antibody that selectively binds calcitonin gene-related peptide and inhibits its activity, in phase 3 migraine trials. Methods Immunogenicity data were analyzed from baseline and double-blind, placebo-controlled phases of the 3-month chronic migraine study REGAIN, the 6-month episodic migraine studies EVOLVE-1 and EVOLVE-2, and from baseline and open-label phases of the 12-month chronic and episodic migraine Study CGAJ. The incidence of baseline antidrug antibodies, treatment-emergent antidrug antibodies, neutralizing antidrug antibodies, and the effect of antidrug antibody titer on pharmacokinetics and pharmacodynamics were assessed. The relationship between antidrug antibody status and efficacy was explored using average change in monthly migraine headache days. Safety analyses assessed the potential relationship between treatment-emergent antidrug antibodies and hypersensitivity events or adverse events related to injection sites. Findings Across studies, 5.9–11.2% of patients had baseline antidrug antibodies. The incidence of treatment-emergent antidrug antibodies was 2.6–12.4% in the galcanezumab group and 0.5–1.7% in the placebo group. The majority of treatment-emergent antidrug antibodies were detected approximately 3–6 months after first study drug dose. Overall, the observed antidrug antibody titer did not impact galcanezumab concentrations, calcitonin gene-related peptide concentrations, or galcanezumab efficacy. There was no evidence that hypersensitivity events or adverse events related to injection sites were mediated by treatment-emergent antidrug antibodies. Interpretation These data showed that immunogenicity did not impact galcanezumab concentrations, calcitonin gene-related peptide concentrations, or the efficacy and hypersensitivity profile of galcanezumab in patients with migraine.

Galcanezumab is a humanized immunoglobulin G (IgG) monoclonal antibody (mAb) indicated for the prevention of migraine that binds to calcitonin gene‐related peptide. A population pharmacokinetic (PK) analysis was performed to characterize galcanezumab PK using data pooled from 7 clinical studies. Clinical studies included healthy individuals and patients with episodic or chronic migraine who were administered between 5 and 300 mg galcanezumab. The PK data were analyzed using nonlinear mixed‐effects modeling. Galcanezumab concentration‐time data were described with a 1‐compartment model with first‐order absorption following subcutaneous administration and linear elimination. At the median body weight of 74 kg, the estimated population apparent clearance (CL/F) was 0.00785 L/h (34% IIV), the apparent volume of distribution was 7.33 L (34% IIV), and half‐life was 27 days. Patient body weight was found to have a modest effect of CL/F, with median galcanezumab concentrations being lower in the heaviest patients compared to the lightest patients, but this outcome was determined not to be clinically relevant in the context of model‐estimated random variability. Dosing adjusted for body weight is not warranted in adults. Age, sex, race/ethnicity, immunogenicity, renal/hepatic markers, and injection‐site location did not affect galcanezumab PK. In conclusion, galcanezumab exhibits PK parameters typical for an IgG mAb administered subcutaneously. The population PK model developed in this study demonstrates that galcanezumab exhibits linear PK that was not influenced in a clinically relevant manner by the patient factors evaluated.

Dopamine (DA) plays a key role in several central functions including cognition, motor activity, and wakefulness. Although efforts to develop dopamine receptor 1 (D1) agonists have been challenging, a positive allosteric modulator represents an attractive approach with potential better drug-like properties. Our previous study demonstrated an acceptable safety and tolerability profile of the dopamine receptor 1 positive allosteric modulator (D1PAM) mevidalen (LY3154207) in single and multiple ascending dose studies in healthy volunteers (Wilbraham et al., 2021). Herein, we describe the effects of mevidalen on sleep and wakefulness in humanized dopamine receptor 1 (hD1) mice and in sleep-deprived healthy male volunteers. Mevidalen enhanced wakefulness (latency to fall asleep) in the hD1 mouse in a dose dependent [3-100 mg/kg, orally (PO)] fashion when measured during the light (zeitgeber time 5) and predominantly inactive phase. Mevidalen promoted wakefulness in mice after prior sleep deprivation and delayed sleep onset by 5.5- and 15.2-fold compared with vehicle-treated animals, after the 20 and 60 mg/kg PO doses, respectively, when compared with vehicle-treated animals. In humans, mevidalen demonstrated a dose-dependent increase in latency to sleep onset as measured by the multiple sleep latency test and all doses (15, 30, and 75 mg) separated from placebo at the first 2-hour postdose time point with a circadian effect at the 6-hour postdose time point. Sleep wakefulness should be considered a translational biomarker for the dopamine receptor 1 positive allosteric modulator mechanism. SIGNIFICANCE STATEMENT: This is the first translational study describing the effects of a selective dopamine receptor 1 positive allosteric modulator (D1PAM) on sleep and wakefulness in the human dopamine receptor 1 mouse and in sleep-deprived healthy male volunteers. In both species, drug exposure correlated with sleep latency, supporting the use of sleep-wake activity as a translational central biomarker for D1PAM. Wake-promoting effects of D1PAMs may offer therapeutic opportunities in several conditions, including sleep disorders and excessive daytime sleepiness related to neurodegenerative disorders.

Purpose To review pharmacokinetic and pharmacodynamic characteristics of antibodies that bind to soluble ligands within the framework of calcitonin gene-related peptide antibodies. Overview Calcitonin gene-related peptide has been implicated in the pathophysiology of migraine. Galcanezumab is an antibody that binds to the ligand calcitonin gene-related peptide. Other antibodies that target calcitonin gene-related peptide include eptinezumab and fremanezumab. To understand how antibodies can affect the extent and duration of free ligand concentrations, it is important to consider the dose and pharmacokinetics of an antibody, and the kinetics of the ligand and antibody–ligand complex. Insights regarding the pharmacokinetic/pharmacodynamic properties of galcanezumab as a probe antibody drug and calcitonin gene-related peptide as its binding ligand regarding its clinical outcomes are provided. Discussion Antibodies are administered parenterally because oral absorption is limited by gastrointestinal degradation and inefficient diffusion through the epithelium. The systemic absorption of antibodies following intramuscular or subcutaneous administration most likely occurs via convective transport through lymphatic vessels into blood. The majority of antibody elimination occurs via intracellular catabolism into peptides and amino acids following endocytosis. Binding of ligand to an antibody reduces the free ligand that is available to interact with the receptor and efficacy is driven by the magnitude and duration of the reduction in free ligand concentration. A galcanezumab pharmacokinetic/pharmacodynamic model shows that galcanezumab decreases free calcitonin gene-related peptide concentrations in a dose- and time-dependent manner and continues to suppress free calcitonin gene-related peptide with repeated dosing. The model provides evidence for a mechanistic linkage to galcanezumab therapeutic effects for the preventive treatment of migraine.

Virginia L Stauffer,1 Ryan Sides,1 Michel Lanteri-Minet,2,3 William Kielbasa,1 Yan Jin,1 Katherine J Selzler,1 Stewart J Tepper4 1Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA; 2Pain Department, CHU Nice, Nice, France; 3Université Cote d’Azur, FHU InovPain, CHU de Nice, Nice, France; 4Geisel School of Medicine at Dartmouth, Hanover, NH, USA Purpose: The aim of this study was to compare the usability and patient-rated experiences of an autoinjector with a prefilled syringe in patients with migraine, who self-administered galcanezumab, and to compare pharmacokinetic parameters between these devices. Materials and methods: Patient-rated experiences with an investigational autoinjector and a prefilled syringe were compared in an open-label, 12-month study of once-monthly injections of galcanezumab 120 or 240mg (NCT02614287). Patient-rated ease of usability was assessed with the Subcutaneous Administration Assessment Questionnaire (SQAAQ) and compared between devices. Positive responses on the SQAAQ were rated as “agree or strongly agree” to 12 statements. Tolerability was assessed by the frequency of injection-site-related adverse events (AEs) by device and injection location. In a separate study, galcanezumab pharmacokinetics in healthy subjects was compared between the devices (NCT02836613). Results: In the open-label clinical trial, 179 patients used both the prefilled syringe and autoinjector at least once. The majority of patients (91%–97%) had positive responses on the SQAAQ to the use of autoinjector across the items assessed. There were 23 injection-site-related AEs with the first self-administered injection with the prefilled syringe (N=7) or autoinjector (N=16; P=0.061), with the most common AE for either device being injection-site pain. There were no significant between-device differences in injection-site-related AEs. For pharmacokinetics, the 90% CI for the ratio (autoinjector/prefilled syringe) of geometric least-square means for the galcanezumab area under the curve (AUC) concentration and maximum concentration (Cmax) was between 0.8 and 1.25, indicating no statistically significant difference in the galcanezumab concentrations regardless of the device used. Conclusion: The ease of usability with either device was comparable, and there were no significant differences in tolerability between the prefilled syringe and autoinjector with the first self-administration; however, the analysis was not powered to detect a clinically significant difference. Galcanezumab pharmacokinetics were comparable between devices. Keywords: galcanezumab, devices, self-administered injections, SQAAQ, pharmacokinetics

Norepinephrine, a neurotransmitter in the autonomic sympathetic nervous system, is deaminated by monoamine oxidase to 3,4-dihydroxyphenylglycol (DHPG). Inhibition of the NE transporter (NET) using DHPG as a biomarker was evaluated using atomoxetine, duloxetine, and edivoxetine as probe NET inhibitors. Pharmacokinetic and pharmacodynamic data were obtained from healthy subjects (n = 160) from 5 clinical trials. An indirect response model was used to describe the relationship between drug plasma concentration and DHPG concentration in plasma and cerebrospinal fluid (CSF). The baseline plasma DHPG concentration (1130-1240 ng/mL) and Imax (33%-37%) were similar for the 3 drugs. The unbound plasma drug IC50 (IC50U ) based on plasma DHPG was 0.973 nM for duloxetine, 0.136 nM for atomoxetine, and 0.041 nM for edivoxetine. The baseline CSF DHPG concentration (1850-2260 ng/mL) was similar for the 3 drugs, but unlike plasma DHPG, the Imax for DHPG was 38% for duloxetine, 53% for atomoxetine, and75% for edivoxetine. The IC50U based on CSF DHPG was 2.72 nM for atomoxetine, 1.22 nM for duloxetine, and 0.794 nM for edivoxetine. These modeling results provide insights into the pharmacology of NET inhibitors and the use of DHPG as a biomarker.

Inhibition of norepinephrine (NE) reuptake into noradrenergic nerves is a common therapeutic target in the central nervous system (CNS). In noradrenergic nerves, NE is oxidized by monoamine oxidase to 3,4-dihydroxyphenylglycol (DHPG). In this study, 40 healthy male subjects received the NE transporter (NET) inhibitor edivoxetine (EDX) or atomoxetine (ATX), or placebo. The pharmacokinetic and pharmacodynamic profile of these drugs in plasma and cerebrospinal fluid (CSF) was assessed. In Part A, subjects received EDX once daily (QD) for 14 or 15 days at targeted doses of 6mg or 9mg. In Part B, subjects received 80mg ATX QD for 14 or 15 days. Each subject received a lumbar puncture before receiving drug and after 14 or 15 days of dosing. Plasma and urine were collected at baseline and after 14 days of dosing. Edivoxetine plasma and CSF concentrations increased dose dependently. The time to maximum plasma concentration of EDX was 2h, and the half-life was 9h. At the highest EDX dose of 9mg, DHPG concentrations were reduced from baseline by 51% at 8h postdose in CSF, and steady-state plasma and urine DHPG concentrations decreased by 38% and 26%, respectively. For 80mg ATX, the decrease of plasma, CSF, or urine DHPG was similar to EDX. Herein we provide clinical evidence that EDX and ATX decrease DHPG concentrations in the periphery and CNS, presumably via NET inhibition. EDX and ATX concentrations measured in the CSF confirmed the availability of those drugs in the CNS.

Purpose To assess the impact of hepatic or renal impairment on the pharmacokinetics (PK) of edivoxetine. Methods Two separate multi-center, open-label studies with males and females were conducted. Subjects were categorized according to their hepatic function, determined by the Child–Pugh classification, or renal function, determined by creatinine clearance using the Cockcroft–Gault equation. Subjects received a single dose of 18 mg in the hepatic impairment study or 6 mg in the renal impairment study. Noncompartmental PK parameters were computed from the edivoxetine plasma concentration–time data. Results In the hepatic study, the geometric least squares mean (GLSM) and 90 % confidence interval (CI) of the ratio [impaired : normal] of area under the concentration versus time curve from time zero to infinity (AUC0-∞; h × ng/mL) was 1.24 (0.93, 1.64) in the mild, 1.60 (1.21, 2.12) in the moderate, and 1.70 (1.28, 2.24) in the severe group. In the renal impairment study, the GLSM (90 % CI) of the ratio [impaired : normal] of AUC0-∞ was 1.13 (0.73, 1.73) in mild, 1.90 (1.28, 2.82) in moderate, 1.55 (0.94, 2.55) in severe, and 1.03 (0.66, 1.59) in ESRD groups. Overall, the GLSM of the ratio [impaired : normal] of Cmax was slightly less than or approximately 1 across the hepatic and renal impairment groups. Across both studies, there were no clinically significant changes in vital signs and laboratory values, the adverse events were mild in severity and mostly related to nervous system and gastrointestinal disorder-related events. Conclusions PK changes in subjects with hepatic or renal impairment were of small magnitude and did not appear to impact overall subject tolerability. Daily dosing of edivoxetine in a larger population of impaired subjects, including those with dual impairment, would aid in establishing edivoxetine tolerability and PK in a clinical practice scenario.

Edivoxetine (LY2216684) is a selective and potent norepinephrine reuptake inhibitor (NERI). The pharmacokinetics (PK) and pharmacodynamics (PD) of edivoxetine were assessed in children and adolescent patients with attention-deficit/hyperactivity disorder (ADHD) following single and once-daily oral doses of edivoxetine.During a phase 1 open-label safety, tolerability, and PK study, pediatric patients were administered edivoxetine at target doses of 0.05, 0.1, 0.2 and 0.3 mg/kg, and blood samples were collected to determine plasma concentrations of edivoxetine for PK assessments and plasma 3,4-dihydroxyphenylglycol (DHPG) concentrations for PD assessments. Edivoxetine plasma concentrations were measured using liquid chromatography with tandem mass spectrometric detection, and DHPG was measured using liquid chromatography with electrochemical detection.Edivoxetine PK was comparable between children and adolescents. The time to maximum concentration (t(max)) of edivoxetine was ∼2 hours, which was followed by a mono-exponential decline in plasma concentrations with a terminal elimination half-life (t(1/2)) of ∼6 hours. Dose-dependent increases in area under the edivoxetine plasma concentration versus time curve from zero to infinity (AUC(0-∞)) and maximum plasma concentration (C(max)) were observed, and there was no discernable difference in the apparent clearance (CL/F) or the apparent volume of distribution at steady state (V(ss)/F) across the dose range. In adolescents, edivoxetine caused a maximum decrease in plasma DHPG concentrations from baseline of ∼28%, most notably within 8 hours of edivoxetine administration.This initial study in pediatric patients with ADHD provides new information on the PK profile of edivoxetine, and exposures that decrease plasma DHPG consistent with the mechanism of action of a NERI. The PK and PD data inform edivoxetine pharmacology and can be used to develop comprehensive population PK and/or PK-PD models to guide dosing strategies.

The central nervous system (CNS) pharmacokinetics (PK) of drugs that have pharmacological targets in the brain are not often understood during drug development, and this gap in knowledge is a limitation in providing a quantitative framework for translating nonclinical pharmacologic data to the clinical patient population. A focus of translational sciences is to improve the efficiency of clinical trial design via a more judicious selection of clinical doses on the basis of nonclinical data. We hypothesize that this can be achieved for CNS-acting drugs based on knowledge of CNS PK and brain target engagement obtained in nonclinical studies. Translating CNS PK models from rat to human can allow for the prediction of human brain PK and the human dose-brain exposure relationship, which can provide insight on the clinical dose(s) having potential brain activity and target engagement. In this study, we explored the potential utility of this translational approach using rat brain microdialysis and PK modeling techniques to predict human brain extracellular fluid PK of atomoxetine and duloxetine. The results show that this translational approach merits consideration as a means to support the clinical development of CNS-mediated drug candidates by enhancing the ability to predict pharmacologically relevant doses in humans in the absence of or in association with other biomarker approaches.

The current study sought to test the efficacy and safety of the novel selective norepinephrine reuptake inhibitor LY2216684 compared to placebo in patients with major depressive disorder (MDD). Escitalopram was used as a control for assay sensitivity. Adult outpatients with MDD, confirmed at screening by the Mini International Neuropsychiatric Interview, a Self-Rated Quick Inventory of Depressive Symptomatology (QIDS-SR) score of at least 12 and a Clinical Global Impression-Severity Score of at least 4, were randomly assigned to LY2216684 (N=269), placebo (N=138), or escitalopram (N=62). Efficacy, safety, and tolerability outcomes were compared during 8 weeks of double-blind treatment. LY2216684 plasma concentrations were measured. LY2216684 did not show statistically significant improvement from baseline compared to placebo in the primary analysis of the Hamilton depression rating scale (HAM-D(17)) total score. Escitalopram demonstrated significant improvement compared to placebo on the HAM-D(17) total score, suggesting adequate assay sensitivity. Both LY2216684 and escitalopram showed statistically significant improvement from baseline on the patient-rated QIDS-SR total score compared to placebo. Headache, nausea, constipation, dry mouth, and insomnia were the most frequently reported adverse events in the LY2216684 group. A 3-6 beats per minute mean increase from baseline in pulse rate was observed in the LY2216684 group. LY2216684 plasma concentrations increased as the dose increased from 3 mg to 12 mg. The results of this initial investigation of LY2216684's efficacy suggest that it may have antidepressant potential. More definitive data to confirm this is necessary. Its safety profile does not preclude further clinical development.

The neurokinin-1 (NK-1) antagonist LY686017 showed activity in preclinical anxiety models. The clinical development of LY686017 included a PET study and a proof-of-concept in social anxiety disorder (SAD). [ 11 C]GR205171 was used healthy volunteers receiving 1–100 mg/d LY686017 for 28 days to determine brain receptor occupancy (RO). The mean NK-1 RO increased ranged from 25% with 1 mg to 93% with 100 mg. Subsequently, a 12-week randomized clinical trial tested LY686017 vs. paroxetine, or placebo in SAD. Pharmacokinetic (PK)/RO modeling based on the PET results predicted that once daily dosing of > 30 mg LY686017 led to sustained trough RO of over 80%. 189 outpatients 1 suffering from SAD were randomly assigned to 12-weeks treatment with 50 mg/d LY686017 ( N = 77), placebo ( N = 74), or 20 mg/d paroxetine ( N = 38). There was no significant difference between LY686017 and placebo as measured with the Liebowitz Social Anxiety scale (LSAS). The active comparator paroxetine showed positive trends on primary and secondary measures. The plasma concentrations were above the level expected to produce maximal brain NK-1 RO based on the PK/RO relationship obtained in the human PET investigation. Thus, further evaluation of LY686017 for the treatment of SAD does not seem warranted.

The purpose of this study was to assess the efficacy and safety of edivoxetine (LY2216684), a selective norepinephrine reuptake inhibitor, in pediatric patients with attention-deficit/hyperactivity disorder (ADHD).A fixed-dose, randomized, double-blind, 8 week study was conducted in patients 6-17 years of age, who were randomized by two strata: 1) Patients with prior stimulant use randomized to placebo, edivoxetine 0.1 mg/kg/day, 0.2 mg/kg/day, or 0.3 mg/kg/day arms in a 1:1:1:1 ratio; 2) Stimulant-naïve patients randomized to placebo, edivoxetine 0.1mg/kg/day, 0.2 mg/kg/day, 0.3 mg/kg/day, or osmotic-release oral system methylphenidate (OROS MPH) (18-54 mg/day based on body weight) arms in a 1:1:1:1:1 ratio. The primary efficacy measure was baseline-to-week 8 change of ADHD Rating Scale (ADHD-RS) total score for edivoxetine 0.2 mg/kg/day and 0.3 mg/kg/day.A total of 340 patients were randomized to placebo (n=78); edivoxetine 0.1 mg/kg/day (n=76), 0.2 mg/kg/day (n=75), or 0.3 mg/kg/day (n=75); or OROS MPH (n=36). In the stimulant-naïve stratum, the positive control, OROS MPH, was significantly superior to placebo in mean ADHD-RS total score change at end-point (-19.46, p=0.015). The edivoxetine 0.2 mg/kg/day and 0.3 mg/kg/day arms had statistically significantly greater improvement than the placebo arm in mean ADHD-RS total score change at end-point (placebo -10.35; edivoxetine 0.2 mg/kg/day -16.09, p0.010; edivoxetine 0.3 mg/kg/day -16.39, p0.010) and Clinical Global Impressions-Improvement score (placebo 3.05; edivoxetine 0.1 mg/kg/day 3.01, p=0.860; edivoxetine 0.2 mg/kg/day 2.54, p=0.013; edivoxetine 0.3 mg/kg/day 2.53, p=0.013). In the overall efficacy-analyses data set (n=270), the effect size estimates for edivoxetine doses 0.1 mg/kg/day, 0.2 mg/kg/day and 0.3 mg/kg/day at the week 8 time point were 0.17, 0.51, and 0.54, respectively (for the stimulant-naïve stratum, the effect size estimate for OROS MPH was 0.69). Compared with placebo, edivoxetine treatment was associated with statistically significant increases in blood pressure and pulse (p0.050), and a smaller increase or slight decrease in weight.Edivoxetine at doses of 0.2 mg/kg/day and 0.3 mg/kg/day demonstrated efficacy in ADHD treatment, despite the presence of a sizeable placebo response. No unexpected adverse events were identified. Clinical Trial Registry identifier: NCT00922636.

The purpose of this study was to assess the clinical outcomes from an open label study of edivoxetine, a selective norepinephrine reuptake inhibitor, in pediatric patients with attention-deficit/hyperactivity disorder (ADHD).This was a multi-cohort open-label study of edivoxetine consisting of a single-dose administration period (Part 1) and an open-label once daily (QD) dose long-term period (Part 2). Adolescents ages 12-17 years and children ages 6-11 years were enrolled in Part 1 and continued to Part 2 where they received 0.05 to 0.3 mg/kg edivoxetine QD for ≤12 months. Safety was assessed by adverse events, vital signs, weight, electrocardiograms, and laboratory tests. In Part 2, Attention-Deficit/Hyperactivity Disorder Rating Scale-Version IV-Parent Reported: Investigator Scored (ADHDRS-IV) and Clinical Global Impressions-ADHD-Severity (CGI-ADHD-S) scores were determined.Fifty-three patients enrolled in Part 1, and 49 continued to Part 2 with a mean exposure duration of 22 weeks. The 31 patients completing Part 2 then entered another long-term open-label study. One serious adverse event of mania was reported; all other treatment-emergent adverse events were mild or moderate in severity. Nausea, decreased appetite, somnolence, increased blood pressure, and upper respiratory tract infection were most frequently reported (three events each). No clinically relevant changes were noted in the laboratory parameters. ADHDRS-IV total score, inattention and hyperactivity/impulsivity subscores, and CGI-ADHD-S scores were statistically significantly improved at endpoint compared with baseline.This study provides preliminary evidence to suggest that edivoxetine at doses ≤0.3 mg/kg/day is safe and may improve ADHD symptoms in pediatric patients. These results require confirmation in larger, double-blind, placebo-controlled trials.

A comprehensive in vivo evaluation of brain penetrability and central nervous system (CNS) pharmacokinetics of atomoxetine in rats was conducted using brain microdialysis. We sought to determine the nature and extent of transport at the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCB) and to characterize brain extracellular and cellular disposition. The steady-state extracellular fluid (ECF) to plasma unbound (uP) concentration ratio (C(ECF)/C(uP)=0.7) and the cerebrospinal fluid (CSF) to plasma unbound concentration ratio (C(CSF)/C(uP)=1.7) were both near unity, indicating that atomoxetine transport across the BBB and BCB is primarily passive. On the basis of the ratios of whole brain concentration to C(ECF) (C(B)/C(ECF)=170), brain cell (BC) concentration to C(ECF) (C(BC)/C(ECF)=219), and unbound brain cell concentration to C(ECF) (C(uBC)/C(ECF)=2.9), we conclude that whole brain concentration does not represent the concentration in the biophase and atomoxetine primarily partitions into brain cells. The distributional clearance at the BBB (Q(BBB)=0.00110 l/h) was estimated to be 12 times more rapid than that at the BCB (Q(BCB)=0.0000909 l/h) and similar to the clearances across brain parenchyma (CL(ECF-BC)=0.00216 l/h; CL(BC-ECF)=0.000934 l/h). In summary, the first detailed examination using a quantitative microdialysis technique to understand the brain disposition of atomoxetine was conducted. We determined that atomoxetine brain penetration is high, movements across the BBB and BCB occur predominantly by a passive mechanism, and rapid equilibration of ECF and CSF with plasma occurs.

Alcohol dependence is a major public health challenge in need of new treatments. As alcoholism evolves, stress systems in the brain play an increasing role in motivating continued alcohol use and relapse. We investigated the role of the neurokinin 1 receptor (NK1R), a mediator of behavioral stress responses, in alcohol dependence and treatment. In preclinical studies, mice genetically deficient in NK1R showed a marked decrease in voluntary alcohol consumption and had an increased sensitivity to the sedative effects of alcohol. In a randomized controlled experimental study, we treated recently detoxified alcoholic inpatients with an NK1R antagonist (LY686017; n = 25) or placebo ( n = 25). LY686017 suppressed spontaneous alcohol cravings, improved overall well-being, blunted cravings induced by a challenge procedure, and attenuated concomitant cortisol responses. Brain functional magnetic resonance imaging responses to affective stimuli likewise suggested beneficial LY686017 effects. Thus, as assessed by these surrogate markers of efficacy, NK1R antagonism warrants further investigation as a treatment in alcoholism.

Atomoxetine is a potent and selective norepinephrine transporter (NET) reuptake inhibitor acting as a nonstimulant for the treatment of attention-deficit/hyperactivity disorder (ADHD). Previous positron emission tomography (PET) studies had failed to demonstrate the feasibility of measuring a dose-dependent and saturable NET occupancy in human brain using [11C]MeNER.To determine if atomoxetine occupies NET in a dose-dependent fashion using (S,S)-[18F]FMeNER-D2 in nonhuman primate brain.A total of eight PET measurements were performed in two cynomolgus monkeys. Each monkey was examined four times with PET: under baseline conditions and after steady-state infusion with 0.03, 0.06, or 0.12 mg/kg/h of atomoxetine. A prolonged intravenous (i.v.) infusion design was developed rather than an i.v. bolus to better mimic an oral absorption profile and to reach plasma steady state.During baseline conditions, (S,S)-[18F]FMeNER-D2 uptake was highest in the locus coeruleus, thalamus, mesencephalon, and the cingulate gyrus, whereas the radioactivity in the caudate was low. Peak equilibrium measurements were achieved using (S,S)-[18F]FMeNER-D2 in contrast to the previously reported data for [11C]MeNER. After administration of atomoxetine, a dose-dependent occupancy from 38 to 82% was observed for various brain regions known to contain high densities of NET.This is the first in vivo PET study to successfully demonstrate the ability to measure a dose-dependent change in NET occupancy in brain using (S,S)-[18F]FMeNER-D2. Furthermore, an asymptotic relationship between N-desmethylatomoxetine plasma concentration and NET occupancy was established. In total, these data encourage further PET studies using (S,S)-[18F]FMeNER-D2 in humans.

Inhaled nitric oxide (iNO) has been shown to reduce pulmonary hypertension associated with several disease states. The effects of iNO are thought to be restricted to the pulmonary vasculature because of its rapid inactivation by hemoglobin. Recent data have suggested, however, that iNO can form nitrosothiols, which can be carried throughout the circulation, thus increasing the half life and bioactivity on NO. Other studies have shown that iNO can affect intestinal ischemia and renal hemodynamics. In this study, rats were exposed to 49 ± 4 ppm or 107 ± 13 ppm NO for 4 h and the lung, spleen, liver, and kidney tissues were removed and measured for NOS II and NOS III protein, nitrotyrosine (NT), and phosphotyrosine (PT) immunoreactivity. Following 107 ppm iNO, increases in NOS III protein expression, NT, and PT were observed in the liver and kidney, but not in the lung or spleen. No such increases were noted after the lower dose of iNO. These results paralleled those shown for isobutyl nitrite that we reported earlier and indicated that iNO can cause changes in protein chemistry in organs and tissues beyond the lungs. Since iNO produced little systemic hemodynamic effects, it is unlikely that the observed biochemical alterations were derived secondarily from physiological changes.

Organic nitrites are nitric oxide (NO) donors that are used predominantly as inhalant drugs of abuse and have been shown to have immunomodulating effects. NO donors can modulate NOS activity and expression, thus altering the level of endogenous NO production. NO can react with superoxide (O(*)(2)(-)) to form peroxynitrite (ONOO(-)), which can nitrate tyrosine residues in proteins and alter tyrosine phosphorylation. We investigated the effects of inhaled isobutyl nitrite (ISBN) on NOS expression, tyrosine nitration, and tyrosine phosphorylation in selected organs of rats. Following exposures of 109 and 1517 ppm ISBN for 4 h, the lung, spleen, liver, and kidney were removed and assayed by SDS-PAGE for NOS III (eNOS), NOS II (iNOS), nitrotyrosine (NT)- and phosphotyrosine (PT)-immunoreactive proteins using specific antibodies. ISBN at 1517 ppm, but not 109 ppm, caused an increase in NOS III expression in the liver and kidney, but not in the lung and spleen. No apparent effect on NOS II expression was observed in these organs. The expressions of NT and PT protein bands (30-200 kDa) were increased in the liver and kidney, but not in the lung and spleen. This increase in NT persisted for 24 h post-exposure. Increased NOS III expression in the liver and kidney may promote peroxynitrite formation and contribute to the increase in NT and PT immunoreactivity. ISBN inhalation may thus cause changes in cellular signaling involving tyrosine phosphorylation. These findings may suggest a mechanistic basis for the apparent immunotoxicity associated with nitrite abuse.

Organic nitrites have been used therapeutically for the treatment of angina pectoris and as diagnostic agents for the evaluation of cardiac heart murmurs. In addition, these highly volatile vasodilators are being used as inhalant drugs of abuse. We developed a gas chromatographic assay using electron capture detection for the analysis of a representative nitrite inhalant, isobutyl nitrite (ISBN), in rat and human whole blood. Unconventional sampling and processing techniques were required because of the high volatility and chemical instability of nitrites in biological fluids. Our method produced a mean recovery of ISBN from rat blood of about 86% over a concentration range of 1.0 to 400 ng/ml. The inter-day coefficient of variation was below 15% at the lowest quantifiable concentration of 1 ng/ml ISBN in rat blood. In this report, we applied the analytical method to obtain new pharmacokinetic information about ISBN. Results show that rats inhaling 900 ppm ISBN for 45 min produced steady-state blood concentrations of about 290 ng/ml, and a rapid elimination half-life of 1.4 min.