vabicaserin and Schizophrenia

The pharmacological treatment of schizophrenia is currently based on the employment of antipsychotic medications showing an antagonism of dopaminergic and serotoninergic inhibitors. 20-40% of patients are drug-resistant or residually symptomatic in the long-term antipsychotic treatment, and new strategies are needed for improving their functional and cognitive impairment.. This systematic review has summarized evidences from the literature regarding the newer pharmacological targets proposed for the treatment of psychosis. We included 128 peer-reviewed articles and 5 other relevant sources published from 2002 to 2020 on PubMed EMBASE, The Cochrane Library, and Google Scholar.. The possible role of glutamate and its receptors as targets of the antipsychotic mechanism of action has been described. Glutamatergic neurotransmission and NMDA receptors hypofunction are involved in the neurobiological explanatory model of psychosis and possibly targeted for the successful treatment of cognitive and residual symptoms. Results show an efficacy of D-cycloserine (antagonist at the Glycine site of the NMDA-R) in the treatment of negative symptoms of schizophrenia as well as Memantine (NMDA- Receptor antagonist) for cognition and psychopathology. The putative antipsychotic effect of cannabidiol on positive symptoms and cognition will also be discussed. The action on serotoninergic and GABAergic receptors will be considered as a new pharmacological target, with a possible efficacy of Vabicaserin on symptoms of psychosis. Mynocicline has shown to induce improvements in cognitive symptoms in schizophrenia, as well as Erythropoietin. Oxytocin has been reported to have an antipsychotic-like effect; moreover, COX-2 inhibitors lead to a reduction in positive symptoms of psychosis, specifically in the first episode of illness.. This narrative report suggests a promising role of new agents in the treatment of Schizophrenia; however, more research is needed to approve their clinical employment.

Topics: Antipsychotic Agents; Cyclooxygenase 2 Inhibitors; Erythropoietin; Glutamic Acid; Heterocyclic Compounds, 4 or More Rings; Humans; Minocycline; Molecular Targeted Therapy; Oxytocin; Receptors, N-Methyl-D-Aspartate; Schizophrenia

The 5-HT(2C) receptor is a highly complex, highly regulated receptor which is widely distributed throughout the brain. The 5-HT(2C) receptor couples to multiple signal transduction pathways leading to engagement of a number of intracellular signaling molecules. Moreover, there are multiple allelic variants of the 5-HT(2C) receptor and the receptor is subject to RNA editing in the coding regions. The complexity of this receptor is further emphasized by the studies suggesting the utility of either agonists or antagonists in the treatment of schizophrenia. While several 5-HT(2C) agonists have demonstrated clinical efficacy in obesity (lorcaserin, PRX-000933), the focus of this review is on the therapeutic potential of 5-HT(2C) agonists in schizophrenia. To this end, the preclinical profile of 5-HT(2C) agonists from a neurochemical, electrophysiological, and a behavioral perspective is indicative of antipsychotic-like efficacy without extrapyramidal symptoms or weight gain. Recently, the selective 5-HT(2C) agonist vabicaserin demonstrated clinical efficacy in a Phase II trial in schizophrenia patients without weight gain and with low EPS liability. These data are highly encouraging and suggest that 5-HT(2C) agonists are potential therapeutics for the treatment of psychiatric disorders.

Topics: Heterocyclic Compounds, 4 or More Rings; Humans; RNA Editing; Schizophrenia; Serotonin 5-HT2 Receptor Agonists; Translational Research, Biomedical

Vabicaserin, a potent 5-HT2C receptor agonist, decreases nucleus accumbens extracellular dopamine levels in rats, without affecting striatal dopamine, indicating mesolimbic selectivity. This is the first study of efficacy, safety and tolerability of vabicaserin in adults with acute schizophrenia. Three hundred fourteen hospitalized subjects were randomized to: Vabicaserin 200 or 400 mg/day, olanzapine 15 mg/day or placebo. Central raters assessed the PANSS and CGI-S. Site raters performed the BPRS and CGI-I. Central rated PANSS Positive (PANSS-PPS) was the primary endpoint. Two hundred eighty-nine subjects were included in the mITT efficacy analysis. Vabicaserin was well tolerated with no major safety concerns. Olanzapine, but not vabicaserin, caused weight gain. Vabicaserin 200 mg/day and olanzapine demonstrated significant improvement at week 6 vs. placebo on PANSS-PSS. A non-significant decrease vs. placebo was observed for 400 mg/day. Both vabicaserin groups demonstrated significant improvement over baseline on PANSS Negative while placebo worsened. Vabicaserin 200 mg/day and olanzapine demonstrated significantly greater improvement over placebo on PANSS Total whereas 400 mg/day showed a trend toward improvement. There was no significant improvement vs. placebo for either vabicaserin group on site-rated BPRS. Vabicaserin 200 mg/day and olanzapine demonstrated significant improvement vs. placebo on CGI-I and CGI-S but not 400 mg/day vabicaserin. Vabicaserin demonstrated efficacy on primary and secondary endpoints at 200 mg/day, but not at 400 mg/day which showed a trend for efficacy. The 200 mg/day vabicaserin group achieved proof of concept using central ratings. Both vabicaserin doses were well tolerated with no significant safety signals and no weight gain.. clinicaltrials.gov. Identifier: NCT00265551.

Topics: Acute Disease; Adult; Analysis of Variance; Antipsychotic Agents; Dose-Response Relationship, Drug; Double-Blind Method; Female; Heterocyclic Compounds, 4 or More Rings; Humans; Male; Middle Aged; Psychiatric Status Rating Scales; Schizophrenia; Treatment Outcome; Young Adult