SEP-363856, a Novel Psychotropic Agent with a Unique, Non-D2 Receptor Mechanism of Action

Background: Allosteric modulators of G-protein coupled receptors regulate receptor activity by binding to sites other than the active site and have emerged as a new and highly desirable class of drugs. PAOPA (3(R)-[(2(S)- pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide), a peptidomimetic analog of Prolyl-Leucyl-Glycinamide, is a potent dopamine D2 receptor allosteric modulator. PAOPA has shown therapeutic effects in pre-clinical models of schizophrenia and extrapyramidal dysfunction. Objective: in this study, we sought to examine the biomolecular underpinnings of PAOPA‘s therapeutic outcomes in preclinical models of schizophrenia. Method: Following sub-chronic (daily for 7 days) administration of PAOPA, we assessed levels of dopamine D2 receptors, receptor kinases (GRK2 (G protein-coupled receptor kinase 2) and Arrestin-3), and phosphorylated mitogenactivated protein kinase (MAPKs), namely, extracellular signal-regulated kinases (ERK1/2) in the hippocampus, medial pre-frontal cortex, nucleus accumbens, pre-frontal cortex, and dorsal striatum via protein quantification. Results: Following 7 days of daily PAOPA treatment, we observed decreased GRK2 and increased dopamine D2 receptor expression in the dorsal striatum. These findings potentially underscore PAOPA’s therapeutic mechanism of action for the positive-like symptoms of schizophrenia in pre-clinical animal models. Additionally, we observed a decline in GRK2 in the hippocampus and an increase in phosphorylated ERK1 in the pre-frontal cortex, suggestive of a role for PAOPA in treating cognitive and/or affective dysfunction in pre-clinical models. Conclusion: While further studies are required to elucidate PAOPA’s mechanism of action, this study builds on prior investigations and develops an early framework to describe the therapeutic mechanism of action of PAOPA.

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Cannabidiol as a potential treatment for psychosis

Therapeutic Advances in Psychopharmacology ◽

10.1177/2045125319881916 ◽

2019 ◽

Vol 9 ◽

pp. 204512531988191 ◽

Cited By ~ 11

Author(s):

Cathy Davies ◽

Sagnik Bhattacharyya

Keyword(s):

Mechanism Of Action ◽

Psychotic Disorders ◽

Dopamine D2 Receptor ◽

Significant Proportion ◽

D2 Receptor ◽

Current Evidence ◽

Novel Treatment ◽

D2 Antagonist ◽

Unique Mechanism ◽

Preclinical Work

Psychotic disorders such as schizophrenia are heterogeneous and often debilitating conditions that contribute substantially to the global burden of disease. The introduction of dopamine D2 receptor antagonists in the 1950s revolutionised the treatment of psychotic disorders and they remain the mainstay of our treatment arsenal for psychosis. However, traditional antipsychotics are associated with a number of side effects and a significant proportion of patients do not achieve an adequate remission of symptoms. There is therefore a need for novel interventions, particularly those with a non-D2 antagonist mechanism of action. Cannabidiol (CBD), a non-intoxicating constituent of the cannabis plant, has emerged as a potential novel class of antipsychotic with a unique mechanism of action. In this review, we set out the prospects of CBD as a potential novel treatment for psychotic disorders. We first review the evidence from the perspective of preclinical work and human experimental and neuroimaging studies. We then synthesise the current evidence regarding the clinical efficacy of CBD in terms of positive, negative and cognitive symptoms, safety and tolerability, and potential mechanisms by which CBD may have antipsychotic effects.

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The role of D1–D2 receptor hetero-dimerization in the mechanism of action of clozapine

European Neuropsychopharmacology ◽

10.1016/j.euroneuro.2008.05.001 ◽

2008 ◽

Vol 18 (9) ◽

pp. 682-691 ◽

Cited By ~ 29

Author(s):

Agata Faron-Górecka ◽

Andrzej Górecki ◽

Maciej Kuśmider ◽

Zygmunt Wasylewski ◽

Marta Dziedzicka-Wasylewska

Keyword(s):

Mechanism Of Action ◽

D2 Receptor

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138 Efficacy and Safety of SEP-363856, a Novel Psychotropic Agent with a Non-D2 Mechanism of Action, in the Treatment of Schizophrenia

CNS Spectrums ◽

10.1017/s1092852920000541 ◽

2020 ◽

Vol 25 (2) ◽

pp. 287-288

Author(s):

Kenneth S. Koblan ◽

Seth Hopkins ◽

Justine Kent ◽

Hailong Cheng ◽

Robert Goldman ◽

...

Keyword(s):

Mechanism Of Action ◽

Effect Size ◽

Repeated Measures ◽

Mixed Model ◽

Subscale Score ◽

Controlled Study ◽

Efficacy And Safety ◽

Meaningful Improvement ◽

Psychotropic Agent ◽

Severity Scores

Abstract:Background:SEP-363856 is a novel psychotropic agent that has shown broad efficacy in animal models of schizophrenia and depression. Its antipsychotic effects appear to be mediated by agonist activity at both trace amine-associated receptor 1 (TAAR1) and 5-HT1A receptors. Notably, SEP-363856 does not bind to any dopaminergic, serotonergic (except 5-HT1A), glutamatergic, or other neuroreceptors thought to mediate the effects of currently available antipsychotics. The aim of this study was to evaluate the efficacy and safety of SEP-363856 in acutely symptomatic patients with schizophrenia.Method:Patients aged 18-40 years meeting DSM-5 criteria for schizophrenia (PANSS total score ≥80) were randomized, double-blind, to 4-weeks of flexible-dose SEP-363856 (50 or 75 mg/d) or placebo. Efficacy measures included the Positive and Negative Syndrome Scale (PANSS) total score (primary), PANSS subscale scores, and the Clinical Global Impressions-Severity (CGI-S) score. Change from baseline in primary and secondary measures were analyzed using a mixed model for repeated measures (MMRM) analysis.Results:Study treatment groups were similar at baseline: SEP-363856 (N=120; male, 64.2%; mean age, 30.0 years; PANSS total score, 101.4) and placebo (N=125; male, 63.2%; mean age, 30.6 years; PANSS total score, 99.7). Least-squares (LS) mean reduction from baseline to week 4 was significantly greater for SEP-363856 vs. placebo on the PANSS total score (-17.2 vs. -9.7; P=0.001; effect size, 0.45), PANSS positive subscale score (-5.5 vs. -3.9; P=0.019; effect size, 0.32), PANSS negative subscale score (-3.1 vs. -1.6; P=0.008; effect size, 0.37), PANSS general psychopathology subscale score (-9.0 vs. -4.7; P<0.001; effect size, 0.51), and the CGI-Severity score (-1.0 vs. -0.5; P<0.001; effect size, 0.52). Discontinuation rates for SEP-363856 vs. placebo were similar overall (21.7% vs. 20.8%) and due to an adverse event (8.3% vs. 6.4%). Change in weight, lipids, glucose and prolactin was similar in SEP-363856 and placebo groups. Adverse events occurring with an incidence ≥2% on SEP-363856 or placebo (with SEP-363856 incidence higher than placebo) were: somnolence (6.7% vs. 4.8%), agitation (5.0% vs. 4.8%), nausea (5.0% vs. 3.2%), diarrhea (2.5% vs. 0.8%), and dyspepsia (2.5% vs. 0%). The proportion of patients who reported any extrapyramidal symptom was 3.3% on SEP-363856 and 3.2% on placebo.Conclusion:In this placebo-controlled study, treatment with SEP-363856, a novel psychotropic agent, was associated with statistically significant and clinically meaningful improvement in schizophrenia symptoms as demonstrated by endpoint change in PANSS total and subscale scores, and CGI-Severity scores. Safety and tolerability findings for SEP-363856 were in general similar to placebo. In particular, SEP-363856 was not associated with extrapyramidal symptoms, akathisia, or hyperprolactinemia, consistent with its non-D2 mechanism of action.ClinicalTrials.gov:NCT02969382Funding Acknowledgements:Supported by funding from Sunovion Pharmaceuticals Inc.

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