Methods for Neuroscience Drug Development: Guidance on Standardization of the Process for Defining Clinical Outcome Strategies in Clinical Trials.

Neurosciences clinical trials continue to have notoriously high failure rates. Appropriate outcomes selection in early clinical trials is key to maximizing the likelihood of identifying new treatments in psychiatry and neurology. The field lacks good standards for designing outcome strategies, therefore The Outcomes Research Group was formed to develop and promote good practices in outcome selection. This article describes the first published guidance on the standardization of the process for clinical outcomes in neuroscience. A minimal step process is defined starting as early as possible, covering key activities for evidence generation in support of content validity, patient-centricity, validity requirements and considerations for regulatory acceptance. Feedback from expert members is provided, regarding the risks of shortening the process and examples supporting the recommended process are summarized. This methodology is now available to researchers in industry, academia or clinics aiming to implement consensus-based standard practices for clinical outcome selection, contributing to maximizing the efficiency of clinical research.

Investigation of genetic determinants of cognitive change in later life.

Cognitive decline is a major health concern and identification of genes that may serve as drug targets to slow decline is important to adequately support an aging population. Whilst genetic studies of cross-sectional cognition have been carried out, cognitive change is less well-understood. Here, using data from the TOMMORROW trial, we investigate genetic associations with cognitive change in a cognitively normal older cohort. We conducted a genome-wide association study of trajectories of repeated cognitive measures (using generalised estimating equation (GEE) modelling) and tested associations with polygenic risk scores (PRS) of potential risk factors. We identified two genetic variants associated with change in attention domain scores, rs534221751 (p = 1 × 10-8 with slope 1) and rs34743896 (p = 5 × 10-10 with slope 2), implicating NCAM2 and CRIPT/ATP6V1E2 genes, respectively. We also found evidence for the association between an education PRS and baseline cognition (at >65 years of age), particularly in the language domain. We demonstrate the feasibility of conducting GWAS of cognitive change using GEE modelling and our results suggest that there may be novel genetic associations for cognitive change that have not previously been associated with cross-sectional cognition. We also show the importance of the education PRS on cognition much later in life. These findings warrant further investigation and demonstrate the potential value of using trial data and trajectory modelling to identify genetic variants associated with cognitive change.

A Neurofunctional Domains Approach to Evaluate D1/D5 Dopamine Receptor Partial Agonism on Cognition and Motivation in Healthy Volunteers With Low Working Memory Capacity.

BACKGROUND: Dopamine D1 receptor signaling plays key roles in core domains of neural function, including cognition and reward processing; however, many questions remain about the functions of circuits modulated by dopamine D1 receptor, largely because clinically viable, selective agonists have yet to be tested in humans. METHODS: Using a novel, exploratory neurofunctional domains study design, we assessed the safety, tolerability, pharmacodynamics, and pharmacokinetics of PF-06412562, a selective D1/D5R partial agonist, in healthy male volunteers who met prespecified criteria for low working memory capacity. Functional magnetic resonance imaging, electrophysiologic endpoints, and behavioral paradigms were used to assess working memory, executive function, and motivation/reward processing following multiple-dose administration of PF-06412562. A total of 77 patients were assigned PF-06412562 (3 mg twice daily and 15 mg twice daily) or placebo administered for 5 to 7 days. Due to the exploratory nature of the study, it was neither powered for any specific treatment effect nor corrected for multiple comparisons. RESULTS: Nominally significant improvements from baseline in cognitive endpoints were observed in all 3 groups; however, improvements in PF-06412562-treated patients were less than in placebo-treated participants. Motivation/reward processing endpoints were variable. PF-06412562 was safe and well tolerated, with no serious adverse events, severe adverse events, or adverse events leading to dose reduction or temporary discontinuation except for 1 permanent discontinuation due to increased orthostatic heart rate. CONCLUSIONS: PF-06412562, in the dose range and patient population explored in this study, did not improve cognitive function or motivation/reward processing more than placebo over the 5- to 7-day treatment period. CLINICALTRIALS.GOV IDENTIFIER: NCT02306876.

Dopaminergic D1 Receptor Stimulation Affects Effort and Risk Preferences.

BACKGROUND: Activation of D1 receptors has been related to successful goal-directed behavior, but it remains unclear whether D1 receptor activation causally tips the balance of weighing costs and benefits in humans. Here, we tested the impact of pharmacologically stimulated D1 receptors on sensitivity to risk, delay, and effort costs in economic choice and investigated whether D1 receptor stimulation would bias preferences toward options with increased costs in a cost-specific manner. METHODS: In a randomized, double-blind, placebo-controlled, parallel-group phase 1 study, 120 healthy young volunteers received either placebo or 1 of 3 doses (6 mg, 15 mg, or 30 mg) of a novel, selective D1 agonist (PF-06412562). After drug administration, participants performed decision tasks measuring their preferences for risky, delayed, and effortful outcomes. RESULTS: Higher doses of the D1 agonist increased the willingness to exert physical effort for reward as well as reduced the preference for risky outcomes. We observed no effects on preferences for delayed rewards. CONCLUSIONS: The current results provide evidence that D1 receptor stimulation causally affects core aspects of cost-benefit decision making in humans.

A novel approach to evaluate the pharmacodynamics of a selective dopamine D1/D5 receptor partial agonist (PF-06412562) in patients with stable schizophrenia.

BACKGROUND: PF-06412562 is an orally bioavailable, selective dopamine D1/D5 receptor partial agonist with a non-catechol structure under evaluation for treatment of cognitive impairment in schizophrenia. AIMS: This randomized, double-blind, placebo-controlled, parallel-group, Phase 1b study examined the pharmacokinetics and pharmacodynamics of three doses of PF-06412562 (3 mg, 9 mg, and 45 mg twice daily) over 15 days in patients with schizophrenia receiving antipsychotics. METHODS: Primary endpoints included adjunctive safety/tolerability and effects on MATRICS Consensus Cognitive Battery Working Memory domain and reward processing (Monetary Incentive Delay) tasks. Exploratory endpoints included other behavioral/neurophysiological tasks, including the N-back task. RESULTS: Among 95 subjects (78% male; mean age 34.8 years), baseline characteristics were similar across groups. The MATRICS Consensus Cognitive Battery Working Memory composite change from baseline on Day 13 improved in all groups, the smallest improvement was observed in the 45 mg group and was significantly smaller than that in the placebo group (two-sided p=0.038). For the Monetary Incentive Delay task (change from baseline in blood-oxygen-level-dependent functional magnetic resonance imaging activation in anterior ventral striatum for the contrast of cue gain>cue no gain on Day 15), no PF-06412562 dose was significantly different from placebo. No doses of PF-06412562 showed a significant difference on two-back task accuracy versus placebo. CONCLUSIONS: Adjunctive treatment with PF-06412562 was safe and well tolerated in patients with schizophrenia. PF-06412562 failed to show clinical benefit relative to placebo on assessments of cognition or reward processing in symptomatically stable patients over a 15-day treatment period. Numerous limitations due to the safety study design warrant further efficacy evaluation for this drug mechanism.

Relating constructs of attention and working memory to social withdrawal in Alzheimer's disease and schizophrenia: issues regarding paradigm selection.

Central nervous system diseases are not currently diagnosed based on knowledge of biological mechanisms underlying their symptoms. Greater understanding may be offered through an agnostic approach to traditional disease categories, where learning more about shared biological mechanisms across conditions could potentially reclassify sub-groups of patients to allow realisation of more effective treatments. This review represents the output of the collaborative group "PRISM", tasked with considering assay choices for assessment of attention and working memory in a transdiagnostic cohort of Alzheimer's disease and schizophrenia patients exhibiting symptomatic spectra of social withdrawal. A multidimensional analysis of this nature has not been previously attempted. Nominated assays (continuous performance test III, attention network test, digit symbol substitution, N-back, complex span, spatial navigation in a virtual environment) reflected a necessary compromise between the need for broad assessment of the neuropsychological constructs in question with several pragmatic criteria: patient burden, compatibility with neurophysiologic measures and availability of preclinical homologues.

Computerized assessment of cognitive impairment among children undergoing radiation therapy for medulloblastoma.

PURPOSE: Advantages to computerized cognitive assessment include increased precision of response time measurement and greater availability of alternate forms. Cogstate is a computerized cognitive battery developed to monitor attention, memory, and processing speed. Although the literature suggests the domains assessed by Cogstate are areas of deficit in children undergoing treatment for medulloblastoma, the validity of Cogstate in this population has not been previously investigated. METHODS: Children participating in an ongoing prospective trial of risk-adapted therapy for newly diagnosed medulloblastoma (n = 73; mean age at baseline = 12.1 years) were administered Cogstate at baseline (after surgery, prior to adjuvant therapy) and 3 months later (6 weeks after completion of radiation therapy). Gold-standard neuropsychological measures of similar functions were administered at baseline. RESULTS: Linear mixed models revealed performance within age expectations at baseline across Cogstate tasks. Following radiation therapy, there was a decline in performance on Cogstate measures of reaction time (Identification and One Back). Females exhibited slower reaction time on One Back and Detection tasks at baseline. Higher-dose radiation therapy and younger age were associated with greater declines in performance. Pearson correlations revealed small-to-moderate correlations between Cogstate reaction time and working memory tasks with well-validated neuropsychological measures. CONCLUSIONS: Cogstate is sensitive to acute cognitive effects experienced by some children with medulloblastoma and demonstrates associations with clinical predictors established in the literature. Correlations with neuropsychological measures of similar constructs offer additional evidence of validity. The findings provide support for the utility of Cogstate in monitoring acute cognitive effects in pediatric cancer.

Unsupervised online neuropsychological test performance for individuals with mild cognitive impairment and dementia: Results from the Brain Health Registry.

INTRODUCTION: The purpose of this study is to compare online neuropsychological test performance of older adults across self-reported diagnoses of being cognitively normal, mild cognitive impairment, and dementia due to Alzheimer's disease and to determine the association of memory concerns and family history of dementia on cognitive performance. METHODS: Participants completed the Cogstate Brief Battery unsupervised at home. RESULTS: Data from 6463 participants over the age of 55 years were analyzed. Adults with the diagnosis of mild cognitive impairment and Alzheimer's disease were associated with poorer performance on all cognitive tests than cognitively normal adults (P < .05 for all), and online cognitive test performance significantly improved diagnostic classification (P < .001). Poorer performance on all cognitive measures was associated with memory concern (P < .001 for all) but not family history of dementia. DISCUSSION: Our results provide preliminary support for the use of cognitive tests taken online without supervision as a means to improve the efficiency of participant screening and recruitment for clinical trials.

A pilot evaluation of a computer-based psychometric test battery designed to detect impairment in patients with cirrhosis.

BACKGROUND: Psychometric testing is used to identify patients with cirrhosis who have developed hepatic encephalopathy (HE). Most batteries consist of a series of paper-and-pencil tests, which are cumbersome for most clinicians. A modern, easy-to-use, computer-based battery would be a helpful clinical tool, given that in its minimal form, HE has an impact on both patients' quality of life and the ability to drive and operate machinery (with societal consequences). AIM: We compared the Cogstate™ computer battery testing with the Psychometric Hepatic Encephalopathy Score (PHES) tests, with a view to simplify the diagnosis. METHODS: This was a prospective study of 27 patients with histologically proven cirrhosis. An analysis of psychometric testing was performed using accuracy of task performance and speed of completion as primary variables to create a correlation matrix. A stepwise linear regression analysis was performed with backward elimination, using analysis of variance. RESULTS: Strong correlations were found between the international shopping list, international shopping list delayed recall of Cogstate and the PHES digit symbol test. The Shopping List Tasks were the only tasks that consistently had P values of <0.05 in the linear regression analysis. CONCLUSION: Subtests of the Cogstate battery correlated very strongly with the digit symbol component of PHES in discriminating severity of HE. These findings would indicate that components of the current PHES battery with the international shopping list tasks of Cogstate would be discriminant and have the potential to be used easily in clinical practice.

Lorazepam Challenge for Individuals at Varying Genetic Risk for Alzheimer Disease.

INTRODUCTION: This study set out to clarify the differential acute cognitive impact of lorazepam based on varying genetic risk for Alzheimer disease. METHODS: Fifty-seven cognitively unimpaired individuals aged 51 to 88, genotyped according to apolipoprotein E (APOE) and translocase of outer mitochondrial membrane (40 homolog) poly-T lengths, completed cognitive testing before, 2.5 and 5 hours after receiving a 1 mg dose of lorazepam. RESULTS: Post-lorazepam, there were significant (P<0.05) declines from baseline in memory, psychomotor processing speed, and executive function. At 2.5 hours, the magnitude of this lorazepam-induced cognitive change was significantly greater in the APOE3/4 group than in the APOE3/3 group for tests of working memory and visuospatial memory/executive function. At 5 hours postchallenge, verbal memory and working memory deficits persisted in the APOE3/4 group compared with the APOE3/3 group. At 5 hours after lorazepam challenge, as compared with the very long/very long group, the short/short group performed slightly worse on a test of working memory (P<0.05), but no other differences were observed among translocase of the outer mitochondrial membrane 40 homolog poly-T variant groups. DISCUSSION: The lorazepam challenge may be unmasking presymptomatic cognitive dysfunction associated with APOE4 carriage.

Preliminary evidence concerning the pattern and magnitude of cognitive dysfunction in major depressive disorder using cogstate measures.

BACKGROUND: Cognitive deficits are common in individuals with major depressive disorder (MDD), and are associated with treatment non-responsiveness and poorer functional outcomes. Characterization of the nature and magnitude of deficits in this population has been limited in part by lack of brief, practical, and well-validated assessment measures. The goal of this study was to use a brief, practical, and repeatable computerized cognitive test battery from Cogstate to examine differences in cognitive functioning between individuals with MDD and healthy controls. METHODS: Forty participants (22 healthy controls (HCs), 18 with MDD) completed a battery of six cognitive measures, as well as measures of intellectual functioning (intellect) and depressive symptom severity. A multivariate analysis of covariance (MANCOVA) was conducted to compare cognitive test performance across groups while controlling for intellect. RESULTS: Individuals with MDD had lower full-scale IQ scores on average, and performed worse on measures of visual attention (d=1.04), verbal learning (d=1.22) and memory (d=1.22), and visuospatial problem solving (d=0.80) than HCs after adjustment for differences in intellect. Psychomotor speed, visual memory, and working memory did not differ between groups. CONCLUSIONS: Cogstate measures appear to be sensitive in assessing deficits in attention, verbal learning and memory, and executive function in individuals with MDD. Further research will be useful in establishing the utility of Cogstate measures for standard use in research and clinical practice.

Posttraumatic stress disorder symptoms and cognitive function in a large cohort of middle-aged women.

BACKGROUND: Posttraumatic stress disorder (PTSD) has been linked to cognitive decline, but research in women is generally lacking. We examined whether trauma and elevated PTSD symptoms were associated with worse cognitive function in middle-aged civilian women. A secondary objective was to investigate the possible role of depression in the relation of PTSD symptoms to cognitive function. METHODS: The sample comprised 14,029 middle-aged women in the Nurses' Health Study II. Lifetime trauma exposure, lifetime PTSD symptoms, and past-week depressive symptoms were measured in 2008. Cognitive function was measured in 2014-2016 using the Cogstate Brief Battery, a self-administered online cognitive battery that assesses psychomotor speed, attention, learning, and working memory. We used linear regression models to estimate mean differences in cognition across PTSD symptom levels. RESULTS: Compared to no trauma, elevated PTSD symptoms consistent with probable PTSD (i.e., 4+ symptoms on a screening questionnaire) were associated with worse performance on psychomotor speed/attention (b = -0.08 standard units, p = .001) and learning/working memory (b = -0.09, p < .001) composites, after adjusting for sociodemographics. Although attenuated, associations remained significant when adjusted for depressive symptoms and other cognitive risk factors. We found the strongest associations among women with comorbid probable PTSD and depression. CONCLUSIONS: PTSD symptoms were negatively related to measures of psychomotor speed/attention and learning/working memory in middle-aged women. Our study adds to a growing literature that suggests that mental disorders are associated with worse cognitive function over the life course.

Feasibility of baseline neurocognitive assessment using Cogstate during the first month of therapy for childhood leukemia.

PURPOSE: Neurocognitive impairment is frequently observed among acute lymphoblastic leukemia (ALL) survivors within the domains of intelligence, attention, processing speed, working memory, learning, and memory. However, few have investigated treatment-induced changes in neurocognitive function during the first months of treatment. Additionally, dysfunction during treatment may be preceded by changes in biomarkers measured within cerebrospinal fluid (CSF). Identification of acute declines in neurocognitive function, as well as predictive genotypes or biomarkers, could guide therapeutic trials of protective interventions. METHODS: This study collects CSF while prospectively assessing neurocognitive functioning (working memory, executive function, learning, processing speed, and attention) of ALL patients using the Cogstate computerized battery at six time points during and after the 2 years of leukemia treatment on a Dana-Farber Cancer Institute ALL Consortium trial. RESULTS: Baseline data collected during the first 3 weeks of induction chemotherapy indicate reliable data as all subjects (N = 34) completed Cogstate baseline testing, while completion and performance checks indicate that 100 % of subjects completed testing and complied with test requirements. The majority (85 %) exhibited normal function compared with age peers. Preliminary analysis of CSF biomarkers (folate, homocysteine, 8-isoprostane, and myelin basic protein) similarly reveals values at baseline within expected normal ranges. CONCLUSIONS: The first month of induction therapy for ALL is a reliable baseline for detecting treatment-induced changes in neurocognitive functioning. Consequently, serial data collection might identify subgroups of ALL patients at increased risk for neurocognitive decline, warranting proactive interventions to improve their level of functioning both during treatment and into survivorship.

Cognitive evolution in natalizumab-treated multiple sclerosis patients.

BACKGROUND: Cognitive dysfunction affects up to 65% of multiple sclerosis (MS) patients and progresses over time. Natalizumab has been shown to be superior to placebo in preserving cognition for the first two years of therapy. OBJECTIVES: The objectives of this study are to understand the impact of natalizumab on cognition beyond two years of therapy and to investigate whether baseline characteristics are predictive of clinical response. METHODS: This is a single-center, 24-month, observational study. Sixty-three patients treated with natalizumab were assessed prior to monthly infusions using a Cogstate battery and the Symbol Digit Modalities Test (SDMT). Patient demographics were collected at baseline. A linear mixed model was conducted with duration of natalizumab therapy as a between-subjects factor (≤2 or >2 years), assessment as a within-subjects factor, and Multiple Sclerosis Severity Score (MSSS) as a covariate. RESULTS: Aside from the MSSS (p = 0.0074), the two groups were identical. No patient showed evidence of sustained cognitive deterioration over the 24-month period. Baseline parameters including impaired cognition did not influence the trajectory of cognitive change over 24 months. CONCLUSIONS: Our results suggest that natalizumab preserves cognition following four to seven years of continuous therapy. This occurs irrespective of baseline characteristics, including impaired cognition.

Neurocognitive Changes after Sustained Ketamine Administration in Children with Chronic Pain.

INTRODUCTION: Ketamine has received attention recently as an agent for chronic pain. There are concerns, however, regarding the neurocognitive changes patients might experience after ketamine exposure. METHODS: This prospective, uncontrolled study describes the neurocognitive functioning of 11 children with chronic pain before and after 2 weeks of daily oral ketamine exposure. Neurocognitive assessment was performed at baseline, Week 2, and Week 14. We hypothesized that there would be declines in neurocognitive scores at either Week 2 or Week 14. RESULTS: No decline in neurocognitive function was detected in the children investigated. Mean scores for tests measuring executive function and memory were improved at Weeks 2 and 14 compared to baseline. DISCUSSION: This study did not detect any decline in neurocognitive scores in a small number of children exposed to 2 weeks of oral ketamine therapy. Randomized, controlled studies of the neurocognitive effects of ketamine in children are recommended to further investigate these preliminary findings.

Simultaneous Treatment of Neurocognitive and Psychiatric Symptoms in Veterans with Post-Traumatic Stress Disorder and History of Mild Traumatic Brain Injury: A Pilot Study of Mindfulness-Based Stress Reduction.

Treating patient populations with significant psychiatric and neurocognitive symptomatology can present a unique clinical dilemma: progress in psychotherapy can be significantly fettered by cognitive deficits, whereas neurocognitive rehabilitation efforts can be ineffective because of psychiatric overlay. Application of mindfulness-based interventions to address either cognitive or psychiatric symptoms in isolation appears efficacious in many contexts; however, it remains unclear whether this type of intervention might help address simultaneous neurocognitive and psychiatric symptomatology. In a pre-post mixed methods design pilot study, nine Veterans with post-traumatic stress disorder (PTSD) and a history of mild traumatic brain injury with chronic cognitive complaints participated in Mindfulness-Based Stress Reduction (MBSR). Clinical interview, questionnaires, and attention and PTSD measures were administered immediately before, immediately after, and 3 months after MBSR completion. Qualitative and quantitative findings suggest high levels of safety, feasibility, and acceptability. Measurement of attention revealed significant improvement immediately following MBSR (p < 0.05, d = 0.57) and largely sustained improvement 3 months after completion of MBSR (p < 0.10, d = 0.48). Significant reduction in PTSD symptoms was found immediately after MBSR (p < 0.05, d = -1.56), and was sustained 3 months following MBSR completion (p < 0.05, d = -0.93). These results warrant a randomized controlled trial follow-up. Potential mechanisms for the broad effects observed will be explored.

Comparison of Cognitive Performance on the Cogstate Brief Battery When Taken In-Clinic, In-Group, and Unsupervised.

OBJECTIVE: Repeat cognitive assessment comparing post-injury performance to a pre-injury baseline is common in concussion management. Although post-injury tests are typically administered in clinical settings, baseline tests may be conducted individually with one-on-one supervision, in a group with supervision, or without supervision. The extent to which these different test settings affect cognitive performance is not well understood. To assess if performance on the Cogstate Brief Battery (CBB) differs across these settings, tests completed individually with one-on-one supervision were compared to those taken either in a group with supervision or individually but without supervision. METHOD: A crossover study design was utilized to account for any effect of individual variability or test order to provide an unbiased examination of the effect of test setting on cognitive performance. Young adult participants completed an individually supervised test either before or after also completing a group or unsupervised test. RESULTS: CBB scores from the same individuals were not significantly different across test settings. Effect sizes ranged in magnitude from .09 to .12 for supervised versus unsupervised tests and from .01 to .37 for individual versus group tests across CBB tasks. CONCLUSION: These results suggest that cognitive testing with the CBB in alternate settings can provide valid cognitive data comparable to data obtained during individually supervised testing.

The nature and rate of cognitive maturation from late childhood to adulthood.

To better understand the nature and rate of cognitive change across adolescence, the Cogstate Brief Battery (CBB) was utilized to assess psychomotor function, attention, working memory, and visual learning in individuals aged 10-18 years old. Since all CBB tasks have equivalent perceptual, motor, and linguistic demands as well as being appropriate for both children and adults, this approach allowed direct across-age comparison of multiple cognitive domains. Exponential decreases in reaction time and linear increases in accuracy were observed across adolescent development in a cross-sectional sample of 38,778 individuals and confirmed in a 5788 individual longitudinal sample with 1-year repeat assessments. These results have important implications for the repeated assessment of cognition during development where expected maturational changes in cognition must be accounted for during cognitive testing.

Exercise, sedentary pastimes, and cognitive performance in healthy older adults.

BACKGROUND: Moderately vigorous physical activity (MVPA) provides a protective affect against cognitive decline and cardiovascular risk factors. Less is known about sedentary pastimes or non exercise physical activity (NEPA) and cognitive performance. METHOD: 125 healthy adults 65 or older with no clinical evidence of cognitive impairment were enrolled. The CogState computerized neurocognitive battery was administered. Leisure activities were measured using the Community Health Activity Program for Seniors (CHAMPS). RESULTS: Sedentary pastimes were associated with executive dysfunction (P = 0.01); MVPA with high memory scores (P = 0.05) and NEPA with improved working memory (P = 0.05). Only sedentary pastimes and executive dysfunction retained significance after correction for multiple comparisons. Smoking and alcohol confounded the association of memory with sedentary pastimes and MVPA. CONCLUSIONS: Study highlights: negative impact of sedentary pastimes on executive function, need for additional investigation of sedentary behavior, NEPA, the impact of addictions upon activity in late life.

The development of associate learning in school age children.

Associate learning is fundamental to the acquisition of knowledge and plays a critical role in the everyday functioning of the developing child, though the developmental course is still unclear. This study investigated the development of visual associate learning in 125 school age children using the Continuous Paired Associate Learning task. As hypothesized, younger children made more errors than older children across all memory loads and evidenced decreased learning efficiency as memory load increased. Results suggest that age-related differences in performance largely reflect continued development of executive function in the context of relatively developed memory processes.