Respiratory Effects of the Atypical Tricyclic Antidepressant Tianeptine in Human Models of Opioid-induced Respiratory Depression.

BACKGROUND: Animal data suggest that the antidepressant and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor modulator tianeptine is able to prevent opioid-induced respiratory depression. The hypothesis was that oral or intravenous tianeptine can effectively prevent or counteract opioid-induced respiratory depression in humans. METHODS: Healthy male and female volunteers participated in two studies that had a randomized, double blind, placebo-controlled, crossover design. First, oral tianeptine (37.5-, 50-, and 100-mg doses with 8 subjects) pretreatment followed by induction of alfentanil-induced respiratory depression (alfentanil target concentration, 100 ng/ml) was tested. Primary endpoint was ventilation at an extrapolated end-tidal carbon dioxide concentration of 55 mmHg (V̇E55). Next, the ability of four subsequent and increasing infusions of intravenous tianeptine (target tianeptine plasma concentrations 400, 1,000, 1,500, and 2,000 ng/ml, each given over 15 min) to counteract remifentanil-induced respiratory depression was determined in 15 volunteers. Ventilation was measured at isohypercpania (baseline ventilation 20 ± 2 l/min). The primary endpoint was minute ventilation during the 60 min of tianeptine versus placebo infusion. RESULTS: Alfentanil reduced V̇E55 to 13.7 (95% CI, 8.6 to 18.8) l/min after placebo pretreatment and to 17.9 (10.2 to 25.7) l/min after 50-mg tianeptine pretreatment (mean difference between treatments 4.2 (-11.5 to 3.0) l/min, P = 0.070). Intravenous tianeptine in the measured concentration range of 500 to 2,000 ng/ml did not stimulate ventilation but instead worsened remifentanil-induced respiratory depression: tianeptine, 9.6 ± 0.8 l/min versus placebo 15.0 ± 0.9 l/min; mean difference, 5.3 l/min; 95% CI, 2.5 to 8.2 l/min; P = 0.001, after 1 h of treatment. CONCLUSIONS: Neither oral nor intravenous tianeptine were respiratory stimulants. Intravenous tianeptine over the concentration range of 500 to 2000 ng/ml worsened respiratory depression induced by remifentanil.

A Phase II Randomized Clinical Trial of the Safety and Efficacy of Intravenous Umbilical Cord Blood Infusion for Treatment of Children with Autism Spectrum Disorder.

OBJECTIVE: To evaluate whether umbilical cord blood (CB) infusion is safe and associated with improved social and communication abilities in children with autism spectrum disorder (ASD). STUDY DESIGN: This prospective, randomized, placebo-controlled, double-blind study included 180 children with ASD, aged 2-7 years, who received a single intravenous autologous (n = 56) or allogeneic (n = 63) CB infusion vs placebo (n = 61) and were evaluated at 6 months postinfusion. RESULTS: CB infusion was safe and well tolerated. Analysis of the entire sample showed no evidence that CB was associated with improvements in the primary outcome, social communication (Vineland Adaptive Behavior Scales-3 [VABS-3] Socialization Domain), or the secondary outcomes, autism symptoms (Pervasive Developmental Disorder Behavior Inventory) and vocabulary (Expressive One-Word Picture Vocabulary Test). There was also no overall evidence of differential effects by type of CB infused. In a subanalysis of children without intellectual disability (ID), allogeneic, but not autologous, CB was associated with improvement in a larger percentage of children on the clinician-rated Clinical Global Impression-Improvement scale, but the OR for improvement was not significant. Children without ID treated with CB showed significant improvements in communication skills (VABS-3 Communication Domain), and exploratory measures including attention to toys and sustained attention (eye-tracking) and increased alpha and beta electroencephalographic power. CONCLUSIONS: Overall, a single infusion of CB was not associated with improved socialization skills or reduced autism symptoms. More research is warranted to determine whether CB infusion is an effective treatment for some children with ASD.

Ensuring Stakeholder Feedback in the Design and Conduct of Clinical Trials for Rare Diseases: ISCTM Position Paper of the Orphan Disease Working Group.

The 1983 Orphan Drug Act in the United States (US) changed the landscape for development of therapeutics for rare or orphan diseases, which collectively affect approximately 300 million people worldwide, half of whom are children. The act has undoubtedly accelerated drug development for orphan diseases, with over 6,400 orphan drug applications submitted to the US Food and Drug Administration (FDA) from 1983 to 2023, including 350 drugs approved for over 420 indications. Drug development in this population is a global and collaborative endeavor. This position paper of the International Society for Central Nervous System Clinical Trials and Methodology (ISCTM) describes some potential best practices for the involvement of key stakeholder feedback in the drug development process. Stakeholders include advocacy groups, patients and caregivers with lived experience, public and private research institutions (including academia and pharmaceutical companies), treating clinicians, and funders (including the government and independent foundations). The authors articulate the challenges of drug development in orphan diseases and propose methods to address them. Challenges range from the poor understanding of disease history to development of endpoints, targets, and clinical trials designs, to finding solutions to competing research priorities by involved parties.

Implications of Pediatric Initiatives on CNS Drug Development for All Ages-2020 and Beyond: Second of Three Sets of Expanded Proceedings from the 2020 ISCTM Autumn Conference on Pediatric Drug Development.

This article expands upon a session, titled "Implications of Pediatric Initiatives on CNS Drug Development for All Ages-2020 and Beyond," that was presented as part of a two-day meeting on pediatric drug development at the International Society for Central Nervous System (CNS) Clinical Trials and Methodology (ISCTM) Autumn Conference in Boston, Massachusetts, in October 2020. Speakers from various areas of pediatric drug development addressed a variety of implications of including children in drug development programs. The speakers wrote summaries of their talks, which are included here. The session's lead chair was Dr. Gahan Pandina, who wrote introductory and closing comments. Dr. Joseph Horrigan addressed the current landscape of pediatric development programs. Dr. Gahan Pandina addressed how the approach to research in pediatric populations affects the drug development process and vice versa. Dr. Alison Bateman-House discussed the ethical implications of research in the pediatric population. Dr. Luca Pani discussed some of the global regulatory issues and challenges concerning research in pediatric patients. Dr. Judith Kando served as a discussant and posed new questions about means of facilitating pediatric research. Finally, Dr. Gahan Pandina provided closing comments and tied together the presented issues. This paper should serve as an expert-informed reference to those interested and involved in CNS drug development programs that are aimed at children and/or required, through regulations, to include children as part of the approval process.

Development of trofinetide for the treatment of Rett syndrome: from bench to bedside.

Rett syndrome (RTT) is rare neurodevelopmental disorder caused by mutations in the MECP2 gene that encodes methyl-CpG-binding protein 2 (MeCP2), a DNA-binding protein with roles in epigenetic regulation of gene expression. Functional loss of MeCP2 results in abnormal neuronal maturation and plasticity, characterized by loss of verbal communication and loss of fine and gross motor function, among others. Trofinetide, a synthetic analog of glycine-proline-glutamate, was approved by the US Food and Drug Administration for the treatment of RTT in adult and pediatric patients aged 2 years and older. Here, we present the development of trofinetide from bench research to clinical studies and emphasize how the collaboration between academia, the pharmaceutical industry, and patient advocacy led to the recent approval. The bench-to-bedside development of trofinetide underscores the value of collaboration between these groups in the development and approval of treatments for rare diseases.

Clinician- and Patient-reported Endpoints in CNS Orphan Drug Clinical Trials: ISCTM Position Paper on Best Practices for Endpoint Selection, Validation, Training, and Standardization.

OBJECTIVE: The International Society of CNS Clinical Trials Methodology (ISCTM) Working Group on Rare Disease/Orphan Drug Development is dedicated to improving and streamlining trials to best develop new treatments for rare diseases. The rarity of these disorders requires a drug development strategy that differs from those of nonrare conditions. Rare disease drug development programs are challenged with small sample sizes, heterogeneous clinical presentations, and few, if any, off-the-shelf endpoints. When disease-specific clinical endpoints exist, they might not be validated and are typically not well known or broadly used in clinical practice. This paper aims to provide an overview of the special issues surrounding endpoints in rare disease drug development, with guidance, practical applications, and discussion. DISCUSSION: The paper covers regulatory considerations in endpoint selection; identification of relevant measurement domains; methods of quantifying clinical meaningfulness; incorporation of patient- and clinician-reported outcomes; considerations for global clinician- and patient-rated clinical assessments; cognition assessment challenges in rare diseases; translation considerations; training, standardization, and calibration of assessors; and endpoint quality assurance. Additionally, it provides guidance and resources for those involved in drug development for rare diseases. CONCLUSION: In keeping with the mission of ISCTM and the rare disease/orphan drug development working group, this article is designed to encourage thoughtful consideration and provide insight and guidance to promote and further efforts in in central nervous system (CNS) rare disease drug development efforts.

A Phase 2 Study of AMO-02 (Tideglusib) in Congenital and Childhood-Onset Myotonic Dystrophy Type 1 (DM1).

BACKGROUND: GSK3ß is an intracellular regulatory kinase that is dysregulated in multiple tissues in type 1 myotonic dystrophy, a rare neuromuscular disorder that manifests at any age. AMO-02 (tideglusib) inhibits GSK3ß activity in preclinical models of type 1 myotonic dystrophy and promotes cellular maturation as well as normalizes aberrant molecular and behavioral phenotypes. This phase 2 study assessed the pharmacokinetics, safety and tolerability, and preliminary efficacy of AMO-02 in adolescents and adults with congenital and childhood-onset type 1 myotonic dystrophy. METHODS: Sixteen subjects (aged 13 to 34 years) with congenital and childhood-onset type 1 myotonic dystrophy received 12 weeks of single-blind fixed-dose oral treatment with either 400 mg (n = 8) or 1000 mg (n = 8) AMO-02 (NCT02858908). Blood samples were obtained for pharmacokinetic assessment. Safety assessments, such as laboratory tests and electrocardiograms, as well as efficacy assessments of syndromal, cognitive, and muscular functioning, were obtained. RESULTS: AMO-02 plasma concentrations conformed to a two-compartment model with first-order absorption and elimination, and dose-dependent increases in exposure (area under the curve) were observed. AMO-02 was generally safe and well-tolerated. No early discontinuations due to adverse events or dose adjustments of AMO-02 occurred. The majority of subjects manifested clinical improvement in their central nervous system and neuromuscular symptoms after 12 weeks of treatment compared with the placebo baseline, with a larger response noted at the 1000 mg/day dose level. AMO-02 exposure (cumulative area under the curve) was significantly correlated (P < 0.01) with change from baseline on several key efficacy assessments. CONCLUSION: AMO-02 has favorable pharmacokinetic and clinical risk/benefit profiles meriting further study as a potential treatment for congenital and childhood-onset type 1 myotonic dystrophy.

A Double-Blind, Randomized, Placebo-Controlled Clinical Study of Trofinetide in the Treatment of Fragile X Syndrome.

BACKGROUND: We analyze the safety and tolerability of trofinetide and provide a preliminary evaluation of its efficacy in adolescent and adult males with fragile X syndrome. METHODS: This study was an exploratory, phase 2, multicenter, double-blind, placebo-controlled, parallel group study of the safety and tolerability of orally administered trofinetide in 72 adolescent and adult males with fragile X syndrome. Subjects were randomly assigned in a 1:1:1 ratio to 35 or 70 mg/kg twice daily trofinetide or placebo for 28 days. Safety assessments included adverse events, clinical laboratory tests, vital signs, electrocardiograms, physical examinations, and concomitant medications. Efficacy measurements were categorized into four efficacy domains, which related to clinically relevant phenotypic dimensions of impairment associated with fragile X syndrome. RESULTS: Both 35 and 70 mg/kg dose levels of trofinetide were well tolerated and appeared to be generally safe. Trofinetide at the 70 mg/kg dose level demonstrated efficacy compared with placebo based on prespecified criteria. On the basis of a permutation test, the probability of a false-positive outcome for the achieved prespecified success was 0.045. In the group analysis, improvement from treatment baseline was demonstrated on three fragile X syndrome-specific outcome measures. CONCLUSIONS: Trofinetide was well tolerated in adolescent and adult males with fragile X syndrome. Despite the relatively short duration of the study, a consistent signal of efficacy at the higher dose was observed in both caregiver and clinician assessments, based on a novel analytical model incorporating evaluation of multiple key symptom areas of fragile X syndrome. This finding suggests a potential for trofinetide treatment to provide clinically meaningful improvement in core fragile X syndrome symptoms.

Population pharmacokinetics of NNZ-2566 in healthy subjects.

NNZ-2566 is a novel, small molecule being developed as a treatment for cognitive impairment in different CNS conditions, including Rett and Fragile-X syndrome, both of which are associated with moderate to severe neurodevelopmental disorder. In the current study we characterise the population pharmacokinetics of NNZ-2566 after administration of single and repeated ascending doses to healthy subjects. A meta-analytical approach was used to analyse pharmacokinetic data from 3 different studies, in which a total of 61 healthy subjects (median age: 23years, range: 19 to 38) were treated with NNZ-2566. Doses of NNZ-2566 ranged from 6.0 to 100mg/kg after oral administration and from 0.1 to 30mg/kg after intravenous administration. A two-compartment model with first order absorption and elimination was found to best describe the pharmacokinetics of NNZ-2566. Inter-individual variability was identified in clearance, absorption rate, central volume of distribution, peripheral volume of distribution and inter-compartmental clearance. Population predicted clearance and central volume of distribution were 10.35L/h and 20.23L, respectively. Dose proportionality was observed across the dose range evaluated in healthy subjects. No accumulation, metabolic inhibition or induction was observed during the course of treatment. In addition, oral bioavailability appeared to vary with food intake. The relatively short half-life of 1.4h suggests the need for a twice or three times daily regimen to maintain relevant blood levels of NNZ-2566.

A Double-Blind, Randomized, Placebo-Controlled Clinical Study of Trofinetide in the Treatment of Rett Syndrome.

BACKGROUND: This study aimed to determine the safety and tolerability of trofinetide and to evaluate efficacy measures in adolescent and adult females with Rett syndrome, a serious and debilitating neurodevelopmental condition for which no therapies are available for its core features. METHODS: This was an exploratory, phase 2, multicenter, double-blind, placebo-controlled, dose-escalation study of the safety and tolerability of trofinetide in 56 adolescent and adult females with Rett syndrome. Subjects were randomly assigned in a 2:1 ratio to 35 mg/kg twice daily of trofinetide or placebo for 14 days; 35 mg/kg twice daily or placebo for 28 days; or 70 mg/kg twice daily or placebo for 28 days. Safety assessments included adverse events, clinical laboratory tests, vital signs, electrocardiograms, physical examinations, and concomitant medications. Efficacy measurements were categorized into four efficacy domains, which related to clinically relevant, phenotypic dimensions of impairment associated with Rett syndrome. RESULTS: Both 35 mg/kg and 70 mg/kg dose levels of trofinetide were well tolerated and generally safe. Trofinetide at 70 mg/kg demonstrated efficacy compared with placebo based on prespecified criteria. CONCLUSION: Trofinetide was well tolerated in adolescent and adult females with Rett syndrome. Although this study had a relatively short duration in a small number of subjects with an advanced stage of disease, consistent efficacy trends at the higher dose were observed in several outcome measures that assess important dimensions of Rett syndrome. These results represented clinically meaningful improvement from the perspective of the clinicians as well as the caregivers.

Assessment of Caregiver Inventory for Rett Syndrome.

Rett syndrome (RTT) requires total caregiver attention and leads to potential difficulties throughout life. The Caregiver Burden Inventory, designed for Alzheimer disease, was modified to a RTT Caregiver Inventory Assessment (RTT CIA). Reliability and face, construct, and concurrent validity were assessed in caregivers of individuals with RTT. Chi square or Fisher's exact test for categorical variables and t tests or Wilcoxon two-sample tests for continuous variables were utilized. Survey completed by 198 caregivers; 70 caregivers completed follow-up assessment. Exploratory factor analysis revealed good agreement for physical burden, emotional burden, and social burden. Internal reliability was high (Cronbach's alpha 0.898). RTT CIA represents a reliable and valid measure, providing a needed metric of caregiver burden in this disorder.

Bupropion extended release compared with escitalopram: effects on sexual functioning and antidepressant efficacy in 2 randomized, double-blind, placebo-controlled studies.

OBJECTIVE: To compare the effects on sexual functioning and the antidepressant efficacy of once-daily bupropion extended release (XL) and escitalopram in adults with major depressive disorder (MDD). METHOD: Adult outpatients with moderate to severe DSM-IV-defined MDD and normal sexual functioning were randomly assigned to receive bupropion XL (300-450 mg/day; N = 276), escitalopram (10-20 mg/day; N = 281), or placebo (N = 273) for up to 8 weeks in 2 identically designed, randomized, double-blind, parallel-group studies (study 1 conducted from February 6, 2003, to June 10, 2004; study 2 conducted from January 21, 2003, to June 15, 2004). Data were analyzed prospectively for each study individually, and pooled data were analyzed retrospectively. RESULTS: In both the individual studies and the pooled dataset, the incidence of orgasm dysfunction at week 8 (primary endpoint) and the incidence of worsened sexual functioning at the end of the treatment period were statistically significantly lower with bupropion XL than with escitalopram (p < .05), not statistically different between bupropion XL and placebo (p > or = .067), and statistically significantly higher with escitalopram than with placebo (p < or = .001). The percentages of patients with orgasm dysfunction at week 8 in study 1, study 2, and the pooled dataset, respectively, were 13%, 16%, and 15% with bupropion XL; 32%, 29%, and 30% with escitalopram; and 11%, 8%, and 9% with placebo. The respective percentages of patients with worsened sexual functioning at the end of the treatment period were 18%, 22%, and 20% with bupropion XL; 37%, 34%, and 36% with escitalopram; and 14%, 16%, and 15% with placebo. Mean changes in Changes in Sexual Functioning Questionnaire scores for all domains at week 8 were statistically significantly worse for escitalopram compared with bupropion XL (p < or = .05). Separation from placebo could not be established at a statistical .05 level for bupropion on 17-item Hamilton Rating Scale for Depression (HAM-D-17) total score. However, escitalopram showed statistical superiority to placebo on HAM-D-17 total score in one of the 2 studies and in the pooled data. Bupropion XL did not statistically differ from escitalopram with respect to mean change in HAM-D-17 total score, HAM-D-17 response or remission rates, percentage of patients much or very much improved on Clinical Global Impressions-Improvement scale scores, or mean changes in the Hospital Anxiety and Depression (HAD) scale total score or Clinical Global Impressions-Severity of Illness scale score at week 8. CONCLUSIONS: Bupropion XL had a sexual tolerability profile significantly better than that of escitalopram with similar HAM-D-17 remission rates and HAD total scores in patients with MDD.

Analysis of electrocardiographic data following use of paroxetine in pediatric depression and obsessive-compulsive disorder.

OBJECTIVE: This retrospective analysis of electrocardiographic (ECG) data investigated the cardiovascular effects of paroxetine 10-50 mg/day in pediatric patients (7-18 years of age). Data were collected from three 8- to 10-week, randomized, placebo-controlled, double-blind trials of paroxetine in pediatric patients with major depressive disorder or obsessive-compulsive disorder. METHOD: Electrocardiograms (ECGs) were retrospectively retrieved from 63 study sites in the United States and Canada. Only patients with at least one screening and one on-treatment ECG were included. ECGs were analyzed for heart rate, QT interval corrected using Bazett's formula (QTcB) and Fridericia's formula (QTcF), at screening and while being treated. PR, R-R, and QRS intervals and the maximum change in QTcB and QTcF from screening to endpoint were determined. Clinically significant thresholds were defined a priori. RESULTS: A total of 1,451 ECGs from 449 patients receiving placebo (n = 207), paroxetine (n = 200), or imipramine (n = 42) were analyzed. Treatment with paroxetine did not significantly increase QTcB or QTcF or any ECG parameters compared with placebo. Treatment with imipramine significantly increased heart rate and QTcB, R-R, and QRS intervals compared with either paroxetine or placebo. CONCLUSIONS: Data from this retrospective study indicate that paroxetine (10-50 mg/day) is unlikely to be associated with significant ECG changes in medically healthy pediatric patients.

Bupropion XL in adults with attention-deficit/hyperactivity disorder: a randomized, placebo-controlled study.

BACKGROUND: Data remain limited on treatment strategies for adults with attention-deficit/hyperactivity disorder (ADHD). This study evaluated the efficacy and safety of an extended-release, once-daily formulation of bupropion (XL) in the treatment of adults with ADHD. METHODS: This multisite, placebo-controlled, 8-week prospective trial evaluated 162 adult patients diagnosed with ADHD (combined and inattentive types). Subjects were treated with up to 450 mg/day of bupropion XL. The primary efficacy endpoint was the proportion of ADHD responders (defined as at least a 30% reduction in the investigator-rated ADHD Rating Scale score) at week 8 (last observation carried forward [LOCF]). RESULTS: Bupropion XL responders (53%) exceeded placebo responders (31%) (p =.004 at week 8) with a significantly greater proportion of bupropion XL responders as early as week 2 (p = .01). Treatment effect size calculated for the ADHD Rating Scale total score was .6. Bupropion XL appeared to provide sustained benefit throughout the day compared with placebo (morning p =.033, afternoon p =.004, evening p = .024). Bupropion XL was safe and well tolerated, with no serious or unexpected adverse events and a low rate of drug-related study discontinuation (5%). CONCLUSIONS: The results from this multisite study indicate that bupropion XL is an effective and well-tolerated nonstimulant treatment for adult ADHD.

Adjunctive Maintenance Lamotrigine for Pediatric Bipolar I Disorder: A Placebo-Controlled, Randomized Withdrawal Study.

OBJECTIVE: This study aimed to compare the efficacy of lamotrigine versus placebo in 10- to 17-year-olds with bipolar I disorder (BP-I) who were receiving conventional bipolar disorder treatment. METHOD: In this randomized withdrawal trial, patients with BP-I of at least moderate severity received lamotrigine during an ≤18-week open-label phase. Patients who maintained a stable lamotrigine dose for ≥2 weeks and Clinical Global Impression-Bipolar Severity of Illness (CGI-BP[S]) score of ≤3 for ≥6 consecutive weeks were randomized to double-blind lamotrigine or placebo for ≤36 weeks. RESULTS: Of 301 patients enrolled, 298 comprised the open-label intention-to-treat population, with 173 (58%) randomized. Of these patients, 41 (24%) completed the study. In the open-label phase, the mean (SD) baseline CGI-BP(S) rating was 4.4 (0.57), and the mean (standard error [SE]) time to stabilization was 101 (1.6) days. During the randomized phase, mean (SE) time to occurrence of a bipolar event (TOBE) for lamotrigine versus placebo (primary endpoint) was 155 (14.7) versus 50 (3.8), 163 (12.2) versus 120 (12.2), and 136 (15.4) versus 107 (13.8) days for the 3 index mood states (depressed, manic/hypomanic, mixed). The primary stratified log-rank analysis of TOBE was not statistically significant (hazard ratio [HR] = 0.63; p = .072); however, the prespecified Cox regression analysis favored lamotrigine (p = .047). In 13- to 17-year-olds, log-rank analysis of TOBE significantly favored lamotrigine (HR = 0.46; p = .015), but not in 10- to 12-year-olds (HR = 0.93; p = .877). Dermatologic events were reported in 4% (open-label phase) and 2% (randomized phase) of patients receiving lamotrigine. Suicidality-related adverse events were reported in 7% (open-label phase) and 7% (randomized phase) of patients receiving lamotrigine. CONCLUSION: Although the primary analysis failed to detect a benefit of add-on lamotrigine for BP-I in 10- to 17-year-olds, lamotrigine may be effective in a subset of older adolescents. Clinical trial registration information-Lamictal as Add-on Treatment for Bipolar I Disorder in Pediatric Patients; http://clinicaltrials.gov/; NCT00723450.

Improving Treatment Trial Outcomes for Rett Syndrome: The Development of Rett-specific Anchors for the Clinical Global Impression Scale.

Rett syndrome is a genetically based neurodevelopmental disorder. Although the clinical consequences of Rett syndrome are profound and lifelong, currently no approved drug treatments are available specifically targeted to Rett symptoms. High quality outcome measures, specific to the core symptoms of a disorder are a critical component of well-designed clinical trials for individuals with neurodevelopmental disorders. The Clinical Global Impression Scale is a measure of global clinical change with strong face validity that has been widely used as an outcome measure in clinical trials of central nervous system disorders. Despite its favorable assay sensitivity in clinical trials, as a global measure, the Clinical Global Impression Scale is not specific to the signs and symptoms of the disorder under study. Development of key anchors for the scale, specific to the disorder being assessed, holds promise for enhancing the validity and reliability of the measure for disorders such as Rett syndrome.

Measuring social communication behaviors as a treatment endpoint in individuals with autism spectrum disorder.

Social communication impairments are a core deficit in autism spectrum disorder. Social communication deficit is also an early indicator of autism spectrum disorder and a factor in long-term outcomes. Thus, this symptom domain represents a critical treatment target. Identifying reliable and valid outcome measures for social communication across a range of treatment approaches is essential. Autism Speaks engaged a panel of experts to evaluate the readiness of available measures of social communication for use as outcome measures in clinical trials. The panel held monthly conference calls and two face-to-face meetings over 14 months. Key criteria used to evaluate measures included the relevance to the clinical target, coverage of the symptom domain, and psychometric properties (validity and reliability, as well as evidence of sensitivity to change). In all, 38 measures were evaluated and 6 measures were considered appropriate for use, with some limitations. This report discusses the relative strengths and weaknesses of existing social communication measures for use in clinical trials and identifies specific areas in need of further development.

Measuring repetitive behaviors as a treatment endpoint in youth with autism spectrum disorder.

Restricted interests and repetitive behaviors vary widely in type, frequency, and intensity among children and adolescents with autism spectrum disorder. They can be stigmatizing and interfere with more constructive activities. Accordingly, restricted interests and repetitive behaviors may be a target of intervention. Several standardized instruments have been developed to assess restricted interests and repetitive behaviors in the autism spectrum disorder population, but the rigor of psychometric assessment is variable. This article evaluated the readiness of available measures for use as outcome measures in clinical trials. The Autism Speaks Foundation assembled a panel of experts to examine available instruments used to measure restricted interests and repetitive behaviors in youth with autism spectrum disorder. The panel held monthly conference calls and two face-to-face meetings over 14 months to develop and apply evaluative criteria for available instruments. Twenty-four instruments were evaluated and five were considered "appropriate with conditions" for use as outcome measures in clinical trials. Ideally, primary outcome measures should be relevant to the clinical target, be reliable and valid, and cover the symptom domain without being burdensome to subjects. The goal of the report was to promote consensus across funding agencies, pharmaceutical companies, and clinical investigators about advantages and disadvantages of existing outcome measures.

A Phase II study of a histamine H3 receptor antagonist GSK239512 for cognitive impairment in stable schizophrenia subjects on antipsychotic therapy.

This Phase II exploratory study assessed GSK239512, a brain penetrant histamine H3 receptor antagonist, versus placebo on cognitive impairment in 50 stable outpatients with schizophrenia. Subjects were randomized to placebo or GSK239512 for 7 weeks (4 weeks titration). GSK239512 was associated with a small positive effect size (ES) on the CogState Schizophrenia Battery (CSSB) Composite Score (ES=0.29, CI=-0.40, 0.99) relative to placebo (primary endpoint). GSK239512's ES on CSSB domains were generally positive or neutral except Processing Speed, which favored placebo (ES=-0.46). Effects on the MATRICS Consensus Cognitive Battery were mostly neutral or favored placebo. GSK239512 was generally well tolerated with an adverse event profile consistent with the known class pharmacology. There was no evidence of overall beneficial effects of GSK239512 for CIAS in this population.

A randomized, double-blind, placebo-controlled, 16-week study of the H3 receptor antagonist, GSK239512 as a monotherapy in subjects with mild-to-moderate Alzheimer's disease.

INTRODUCTION: Histaminergic H3 receptors may play a role in modulating cholinergic and monoaminergic neurotransmission. This Phase II study evaluated the efficacy and safety of GSK239512, a highly potent, brain penetrant H3 receptor antagonist as monotherapy treatment for subjects with mild-to-moderate probable Alzheimer's disease (AD). METHODS: In this 16-week, double-blind, randomized, parallel group study, 196 currently untreated subjects with mild-tomoderate AD (Mini Mental State Examination [MMSE] 16-24) received GSK239512 (n=97); or placebo (n=99) administered orally each morning. After a two-week placebo run-in period GSK239512 was up-titrated over 4 weeks in a flexible manner (10-20-40-80 microgram [µg]) followed by a 12-week Maintenance Phase. Co-primary efficacy endpoints were change from baseline in Episodic Memory and Executive Function/Working Memory composite scores from the CogState neuropsychological test battery (NTB) at Week 16. RESULTS: Compared to placebo, GSK239512 improved Episodic Memory at Week 16 (Effect Size [ES] =0.35; p=0.0495). No statistically significant differences were observed on other cognitive domains or on clinical measures including the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADASCog). GSK239512 treatment was associated with mild to moderate adverse events with headache, dizziness and events related to sleep disturbances being the most common and more pronounced in the early titration period when subjects were first being exposed to GSK239512 at the lower 10µg and 20µg doses. There were no clinically relevant changes in other safety parameters. CONCLUSION: GSK239512, at doses up to 80µg/day, improved Episodic Memory in patients with mildto- moderate AD. However, no improvements were observed on Executive Function/Working Memory or other domains of cognition. No changes were observed on any of the clinical measures included as secondary endpoints (including ADAS-Cog) indicating that GSK239512 failed to show benefit in this population. GSK239512 had an acceptable safety and tolerability profile. These findings suggest that H3 antagonists may, at most, have modest and selective effects on cognitive function in patients with mild-to-moderate AD.