Results of a randomized double-blind study evaluating luvadaxistat in adults with Friedreich ataxia.

Objectives: Friedreich ataxia (FRDA) is a rare disorder with progressive neurodegeneration and cardiomyopathy. Luvadaxistat (also known as TAK-831; NBI-1065844), an inhibitor of the enzyme d-amino acid oxidase, has demonstrated beneficial effects in preclinical models relevant to FRDA. This phase 2, randomized, double-blind, placebo-controlled, parallel-arm study evaluated the efficacy and safety of oral luvadaxistat in adults with FRDA.

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.

Activation of D1 receptors affects human reactivity and flexibility to valued cues.

Reward-predicting cues motivate goal-directed behavior, but in unstable environments humans must also be able to flexibly update cue-reward associations. While the capacity of reward cues to trigger motivation ('reactivity') as well as flexibility in cue-reward associations have been linked to the neurotransmitter dopamine in humans, the specific contribution of the dopamine D1 receptor family to these behaviors remained elusive. To fill this gap, we conducted a randomized, placebo-controlled, double-blind pharmacological study testing the impact of three different doses of a novel D1 agonist (relative to placebo) on reactivity to reward-predicting cues (Pavlovian-to-instrumental transfer) and flexibility of cue-outcome associations (reversal learning).

Phosphodiesterase 10A Inhibitor Monotherapy Is Not an Effective Treatment of Acute Schizophrenia.

Background: Current treatments for psychotic symptoms associated with schizophrenia often provide inadequate efficacy with unacceptable adverse effects. Improved therapeutics have long been a goal of research. Preclinical testing suggests that phosphodiesterase 10A (PDE10A) inhibitors may provide a novel approach to treating psychosis associated with schizophrenia.

Dopaminergic D Receptor Stimulation Affects Effort and Risk Preferences.

Background: Activation of D receptors has been related to successful goal-directed behavior, but it remains unclear whether D receptor activation causally tips the balance of weighing costs and benefits in humans. Here, we tested the impact of pharmacologically stimulated D receptors on sensitivity to risk, delay, and effort costs in economic choice and investigated whether D 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 D agonist (PF-06412562).

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.

A Proof-of-Concept Study Evaluating the Phosphodiesterase 10A Inhibitor PF-02545920 in the Adjunctive Treatment of Suboptimally Controlled Symptoms of Schizophrenia.

Background: Effective treatments for managing suboptimal clinical responses to current therapy for schizophrenia remain a critical unmet need. Phosphodiesterase 10A (PDE10A) inhibition represents a mechanistically novel approach to the treatment of schizophrenia, with preclinical studies suggesting improvements in partially responsive symptoms could be achieved via adjunctive use of the PDE10A inhibitor PF-02545920. Therefore, the adjunctive safety, tolerability, pharmacokinetics, and efficacy of multiple repeat doses of PF-02545920 were investigated in a phase 1b study and subsequent phase 2 study.

A Phase I Study of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Novel Dopamine D1 Receptor Partial Agonist, PF-06669571, in Subjects with Idiopathic Parkinson's Disease.

Background And Objectives: There is an unmet medical need for additional treatment options for Parkinson's disease. This was a Phase I, double-blind clinical trial assessing safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple doses of the novel dopamine D1 receptor partial agonist, PF-06669571, in subjects with idiopathic Parkinson's disease on a stable dose of L-DOPA.

Methods: Subjects received PF-06669571 (or matching placebo) titrated from 1 mg to 3 mg over 7 days.

First-in-Human Assessment of the Novel PDE2A PET Radiotracer 18F-PF-05270430.

Unlabelled: This was a first-in-human study of the novel phosphodiesterase-2A (PDE2A) PET ligand (18)F-PF-05270430. The primary goals were to determine the appropriate tracer kinetic model to quantify brain uptake and to examine the within-subject test-retest variability.

Methods: In advance of human studies, radiation dosimetry was determined in nonhuman primates.

New approaches for the treatment of sleep disorders.

Epidemiological studies have established that sleep disorders are common and often untreated. Besides having a negative impact on overall health, these conditions can significantly disrupt normal daily functions. While a number of drugs are employed in the treatment of sleep disorders, safety, tolerability, and variable efficacy limit their utility.

A double-blind, placebo-controlled study of the efficacy and safety of desvenlafaxine succinate in the treatment of major depressive disorder.

Objective: This study evaluated the efficacy and safety of desvenlafaxine succinate extended-release in major depressive disorder (MDD).

Method: Adult outpatients with DSM-IV-defined MDD were randomly assigned to desvenlafaxine 100 mg/day (N = 114), 200 mg/day (N = 116), or 400 mg/day (N = 113) or placebo (N = 118) for 8 weeks. Efficacy variables included change from baseline in the 17-item Hamilton Rating Scale for Depression (HAM-D(17), the primary efficacy measure), Clinical Global Impressions-Improvement scale (CGI-I), Montgomery-Asberg Depression Rating Scale, Clinical Global Impressions-Severity of Illness scale (CGI-S), rates of response (> or = 50% decrease from baseline HAM-D(17) score) and remission (HAM-D(17) score < or =7), and Visual Analog Scale-Pain Intensity overall score.

Effects of psychiatric medications on sleep and sleep disorders.

Insomnia is a significant public health concern that has prompted substantial efforts to develop treatment and management strategies. A significant proportion of complaints of insomnia are related to psychiatric conditions such as anxiety disorders and depression, and treatments for these disorders are known to exert both direct and indirect benefits on sleep as well as some negative effects on sleep and sleep physiology. Insomnia is also a prominent symptom of a number of other psychiatric disorders, including schizophrenia and bipolar disorder.

Systematic identification and classification of adverse events in human research.

Widely accepted standards and safeguards for research participants now include systematic surveillance and recording of adverse events. In the absence of a uniform regulation or structure for such reporting, each institution must now establish suitable yet efficient procedures to accomplish this task. We report herein our single center experience with a customized data collection, storage and review system specifically designed to identify and react appropriately to adverse events.

Comparative effects of mirtazapine and fluoxetine on sleep physiology measures in patients with major depression and insomnia.

Background: Sleep complaints are common in patients with major depressive disorder (MDD). Both MDD and antidepressant drugs characteristically alter objective sleep measures. This study compares the effects of mirtazapine and fluoxetine on sleep continuity measures in DSM-IV MDD patients with insomnia.

Efficacy of sertraline in severe generalized social anxiety disorder: results of a double-blind, placebo-controlled study.

Background: Generalized social anxiety disorder is an early onset, highly chronic, frequently disabling disorder with a lifetime prevalence of approximately 13%. The goal of the current study was to evaluate the efficacy and tolerability of sertraline for the treatment of severe generalized social anxiety disorder in adults.

Method: After a 1-week single-blind placebo lead-in period, patients with DSM-IV generalized social phobia were randomly assigned to 12 weeks of double-blind treatment with flexible doses of sertraline (50-200 mg/day) or placebo.