pimavanserin and Schizophrenia

Parkinson´s disease (PD) is a synucleinopathy that affects millions of people worldwide and leads to progressive disability. Psychosis is highly prevalent in PD patients and is associated with poor prognosis. Until April 2016, there were no licensed drugs available in the United States of America (USA) for the treatment of PD psychosis (PDP). Pimavanserin is the first Food and Drug Administration approved medicine for the treatment of hallucinations and delusions associated with PDP.. A MEDLINE literature search, publicly available information provided by ACADIA Pharmaceuticals, and expert opinion were used for this review. A review of PDP, its current treatment and limitations is followed by the rationale for development of pimavanserin. The mechanism of action, preclinical data, pharmacokinetics, pharmacodynamics, and clinical data supporting the efficacy and safety of pimavanserin in PDP are reviewed. We also describe the potential benefits of pimavanserin in other contexts such as schizophrenia and sleep disorders.. Pimavanserin is an antipsychotic with a unique mechanism of action (5-HT2A receptor inverse agonist) and no measurable dopaminergic activity; it has been demonstrated to be efficacious, well tolerated and safe for the treatment of PDP. The development of pimavanserin as an antipsychotic represents a major breakthrough in the pharmacotherapy of psychotic symptoms associated with PD.

Topics: Antipsychotic Agents; Humans; Parkinson Disease; Piperidines; Psychotic Disorders; Schizophrenia; Serotonin 5-HT2 Receptor Agonists; Urea

Serotonin (5-hydroxytryptamine, or 5-HT) receptors mediate a plethora of physiological phenomena in the brain and the periphery. Additionally, serotonergic dysfunction has been implicated in nearly every neuropsychiatric disorder. The effects of serotonin are mediated by fourteen GPCRs. Both the therapeutic actions and side effects of commonly prescribed drugs are frequently due to nonspecific actions on various 5-HT receptor subtypes. For more than 20 years, the search for clinically efficacious drugs that selectively target 5-HT receptor subtypes has been only occasionally successful. This review provides an overview of 5-HT receptor pharmacology and discusses two recent 5-HT receptor subtype-selective drugs, lorcaserin and pimavanserin, which target the 5HT2C and 5HT2A receptors and provide new treatments for obesity and Parkinson's disease psychosis, respectively.

Topics: Benzazepines; Diabetes Mellitus, Type 2; Heart Valve Diseases; Humans; Molecular Structure; Obesity; Parkinson Disease; Piperidines; Receptors, Serotonin; Schizophrenia; Serotonin; Serotonin 5-HT2 Receptor Agonists; Serotonin 5-HT2 Receptor Antagonists; Urea

All approved antipsychotic drugs share an affinity for the dopamine 2 (D(2)) receptor; however, these drugs only partially ameliorate the symptoms of schizophrenia. It is, therefore, of paramount importance to identify new treatment strategies for schizophrenia.. Preclinical, clinical and post-mortem studies of the serotonin 5-HT(2A) system in schizophrenia are reviewed. The implications of a combined D(2) and 5-HT(2A) receptor blockade, which is obtained by several current antipsychotic drugs, are discussed, and the rationale for the development of more selective 5-HT(2A) receptor antagonists is evaluated. Moreover, the investigational pipeline of major pharmaceutical companies is examined and an Internet search conducted to identify other pharmaceutical companies investigating 5-HT(2A) receptor antagonists for the treatment of schizophrenia.. 5-HT(2A) receptor antagonists appear to assume an intermediate position by being marginally superior to placebo but inferior to conventional antipsychotic drugs. Three previous 5-HT(2A) receptor antagonists have been discontinued after Phase II or III trials, and available Phase IIa data on the remaining 5-HT(2A) receptor antagonist will need substantial additional validation to be approved as a new treatment strategy against schizophrenia.

Topics: Antipsychotic Agents; Brain; Fluorobenzenes; Humans; Phenols; Piperidines; Positron-Emission Tomography; Receptor, Serotonin, 5-HT2A; Schizophrenia; Serotonin 5-HT2 Receptor Antagonists; Urea

Pimavanserin tartrate is the first 5-HT(2A) inverse agonist to enter clinical trials as a treatment for L-dopa-induced psychosis in Parkinson's disease and for augmentation of low-dose risperidone treatment in schizophrenia. Pimavanserin is also being evaluated as a possible anti-insomnia drug.. To discuss the potential of pimavanserin to fill multiple therapeutic needs.. The problems with currently approved antipsychotics and sleep agents are explored to highlight how pimavanserin might address some longstanding issues in the treatment of psychosis and insomnia.. In Phase II clinical trials, pimavanserin seemed to be safe, well-tolerated and efficacious in treating L-dopa-induced psychosis without worsening motor symptoms. Pimavanserin also potentiated the therapeutic effects of low-dose risperidone, reduced haloperidol-induced akathisia, and increased slow-wave sleep in older individuals.

Topics: Clinical Trials as Topic; Humans; Molecular Structure; Parkinson Disease; Piperidines; Schizophrenia; Serotonin 5-HT2 Receptor Agonists; Treatment Outcome; Urea

Negative symptoms of schizophrenia are associated with adverse clinical outcomes, but there are few effective treatments. We aimed to assess the effects of pimavanserin, a selective 5-HT. The ADVANCE study was a phase 2, 26-week, randomised, double-blind, placebo-controlled study of pimavanserin in stable outpatients with schizophrenia aged 18-55 years with predominant negative symptoms. Patients were randomly assigned (1:1) across 83 sites (18 in North America and 65 in Europe) to receive pimavanserin or placebo daily, added to an ongoing antipsychotic medication, per a computer-generated schedule (stratification by geographical region). Eligible patients had a score of at least 20 on the sum of seven Positive and Negative Syndrome Scale (PANSS) Marder negative factor items (and scores of ≥4 on at least three or ≥5 on at least two of negative symptom items). The starting dosage of 20 mg of pimavanserin or placebo could be adjusted to 34 mg or 10 mg within the first 8 weeks of the study, after which dosage remained stable until the end of the study. Both pimavanserin and placebo were administered orally once daily as two individual tablets (pimavanserin tablets were either 10 mg or 17 mg). The primary endpoint was change in total score using the 16-item Negative Symptom Assessment (NSA-16) from baseline to week 26. Primary outcomes were analysed in patients who received at least one dose of the study drug and had NSA-16 assessments at baseline and at least once post-baseline (full analysis set). Safety outcomes were analysed in patients who had received at least one dose of the study drug. This trial is registered with ClinicalTrials.gov, NCT02970305, and is complete.. Between Nov 4, 2016, and April 16, 2019, we randomly assigned 403 patients to pimavanserin (n=201; 131 [65%] male; 187 [93%] White) or placebo (n=202; 137 [68%] male, 186 (92%) White), of whom 400 were included in the efficacy analysis (199 in the pimavanserin group, 201 in the placebo group). Mean age was 37·7 years (SD 9·4) in the pimavanserin group and 36·7 (9·2) years in the placebo group. The change in total NSA-16 score from baseline to week 26 was significantly improved with pimavanserin (least squares mean -10·4 [SE 0·67]) versus placebo (least squares mean -8·5 [0·67]; p=0·043; effect size: 0·211). The number of patients with treatment-emergent adverse events (TEAEs) was similar between groups: 80 (40%) patients experienced TEAEs in the pimavanserin group and 71 (35%) in the placebo group. Most TEAEs were headache (6% [n=13] vs 5% [n=10]) and somnolence (5% [n=11] vs 5% [n=10]). One patient from the placebo group reported severe headache (0·5%), rhinorrhoea (0·5%), cough (0·5%), and influenza (0·5%). In the pimavanserin group, one patient reported severe toothache (0·5%), and two patients had worsening of schizophrenia (1%). Mean change in QTcF interval was higher with pimavanerin (4·5 ms [SD 18·0]) than with placebo (0·0 ms [16·0]).. Stable patients with predominant negative symptoms of schizophrenia showed a reduction in negative symptoms after treatment with pimavanserin. However, given the small effect size, further investigation with optimised dosing is warranted to determine the clinical significance of this effect.. Acadia Pharmaceuticals.

Topics: Adolescent; Adult; Double-Blind Method; Europe; Female; Humans; Male; Middle Aged; North America; Outcome Assessment, Health Care; Piperidines; Schizophrenia; Serotonin 5-HT2 Receptor Antagonists; Urea; Young Adult

Most atypical antipsychotic drugs (APDs), e.g. risperidone (RIS), produce more extensive blockade of brain serotonin (5-HT)(2A) than dopamine (DA) D(2) receptors. This distinguishes them from typical APDs, e.g. haloperidol (HAL). Our objective was to test the hypothesis that augmentation of low doses of RIS or HAL (2mg/day) with pimavanserin (PIM), a selective 5-HT(2A) inverse agonist, to enhance 5-HT(2A) receptor blockade, can achieve efficacy comparable to RIS, 6mg/day, but with lesser side effects. In a multi-center, randomized, double-blind, 6week trial, 423 patients with chronic schizophrenia experiencing a recent exacerbation of psychotic symptoms were randomized to RIS2mg+placebo (RIS2PBO), RIS2mg+PIM20mg (RIS2PIM), RIS6mg+PBO (RIS6PBO), HAL2mg+PBO (HAL2PBO), or HAL2mg+PIM20mg (HAL2PIM). Improvement in psychopathology was measured by the PANSS and CGI-S. The reduction in PANSS Total Score with RIS2PIM at endpoint was significantly greater than RIS2PBO: -23.0 vs. -16.3 (p=0.007), and not significantly different from the RIS6PBO group: -23.2 points. The percentage of patients with ≥20% improvement at day 15 in the RIS2PIM group was 62.3%, significantly greater than the RIS6PBO (42.1%; p=0.01) and the RIS2PBO groups (37.7%; p=0.002). Weight gain and hyperprolactinemia were greater in the RIS6PBO group than the RIS2PIM group but there was no difference in extrapyramidal side effects (EPS). HAL2PBO and HAL2PIM were not significantly different from each other in efficacy but HAL2PIM had less EPS at end point. Both HAL groups and RIS6PBO showed equal improvement in psychopathology at endpoint, indicating HAL 2mg/day is effective to treat an acute exacerbation in chronic schizophrenia patients. In conclusion, a sub-effective RIS dose combined with PIM to enhance 5-HT(2A) receptor blockade provided faster onset of action, and at endpoint, equal efficacy and better safety, compared to standard dose RIS. These results support the conclusion that 5-HT(2A) receptor blockade is a key component of the action of some atypical APDs and can reduce EPS due to a typical APD.

Topics: Adolescent; Adult; Aged; Antipsychotic Agents; Dose-Response Relationship, Drug; Double-Blind Method; Drug Interactions; Female; Follow-Up Studies; Haloperidol; Humans; Male; Middle Aged; Piperidines; Psychiatric Status Rating Scales; Risperidone; Schizophrenia; Time Factors; Urea; Young Adult

Clozapine was the widely accepted gold standard treatment for treatment resistant psychotic symptoms. Clozapine has efficacy of about 50% and some responding patients have to discontinue it due to serious adverse effects. The search for novel agents to use for clozapine-non-responders continues. One such possible agent is the non-dopaminergic antipsychotic pimavanserin, an inverse agonist of serotonin 5-HT2A receptors which was recently approved for the hallucinations and delusions of Parkinson's Disease Psychosis. We report here the successful results of using pimavanserin in patients with refractory hallucinations and delusions who failed to respond to clozapine. We also report similar results in refractory psychosis patients who did not receive clozapine.. We present ten cases of patients with schizophrenia and schizoaffective disorder with refractory hallucinations and delusions who received a trial of pimavanserin when clozapine or multiple antipsychotics failed. Six of ten patients had not responded to a clozapine trial. The subjects' ages ranged between 21 and 77 years and were followed up for several months.. All 10 patients with refractory hallucinations and delusions showed marked response to pimavanserin 34 mg/day within 4-8 weeks, with continuation of the response for several months of follow-up. Improvements in negative symptoms and social functioning were also observed in several patients.. This series of 10 cases of patients with refractory psychosis who responded to pimavanserin is an important new finding that has never been reported before. Controlled studies comparing clozapine and pimavanserin in refractory schizophrenia are warranted to confirm these clinical observations.

Topics: Adult; Aged; Antipsychotic Agents; Clozapine; Delusions; Drug Resistance; Female; Hallucinations; Humans; Male; Middle Aged; Piperidines; Psychotic Disorders; Retrospective Studies; Schizophrenia; Serotonin 5-HT2 Receptor Antagonists; Urea; Young Adult

Subchronic administration of an N-methyl-D-aspartate receptor (NMDAR) antagonist, e.g. phencyclidine (PCP), produces prolonged impairment of novel object recognition (NOR), suggesting they constitute a hypoglutamate-based model of cognitive impairment in schizophrenia (CIS). Acute administration of atypical, e.g. lurasidone, but not typical antipsychotic drugs (APDs), e.g. haloperidol, are able to restore NOR following PCP (acute reversal model). Furthermore, atypical APDs, when co-administered with PCP, have been shown to prevent development of NOR deficits (prevention model). Most atypical, but not typical APDs, are more potent 5-HT(2A) receptor inverse agonists than dopamine (DA) D2 antagonists, and have been shown to enhance cortical and hippocampal efflux and to be direct or indirect 5-HT(1A) agonists in vivo. To further clarify the importance of these actions to the restoration of NOR by atypical APDs, sub-effective or non-effective doses of combinations of the 5-HT(1A) partial agonist (tandospirone), the 5-HT(2A) inverse agonist (pimavanserin), or the D2 antagonist (haloperidol), as well as the combination of all three agents, were studied in the acute reversal and prevention PCP models of CIS. Only the combination of all three agents restored NOR and prevented the development of PCP-induced deficit. Thus, this triple combination of 5-HT(1A) agonism, 5-HT(2A) antagonism/inverse agonism, and D2 antagonism is able to mimic the ability of atypical APDs to prevent or ameliorate the PCP-induced NOR deficit, possibly by stimulating signaling cascades from D1 and 5-HT(1A) receptor stimulation, modulated by D2 and 5-HT(2A) receptor antagonism.

Topics: Animals; Antipsychotic Agents; Disease Models, Animal; Dopamine D2 Receptor Antagonists; Haloperidol; Isoindoles; Memory Disorders; Phencyclidine; Piperazines; Piperidines; Pyrimidines; Random Allocation; Rats, Long-Evans; Receptor, Serotonin, 5-HT1A; Receptor, Serotonin, 5-HT2A; Receptors, Dopamine D2; Recognition, Psychology; Schizophrenia; Schizophrenic Psychology; Serotonin 5-HT1 Receptor Agonists; Serotonin 5-HT2 Receptor Agonists; Urea

Hypoglutamatergic function may contribute to cognitive impairment in schizophrenia (CIS). Subchronic treatment with the N-methyl-D-aspartate receptor antagonist, phencyclidine (PCP), induces enduring deficits in novel object recognition (NOR) in rodents. Acute treatment with atypical antipsychotic drugs (APDs), which are serotonin (5-HT)(2A)/dopamine D(2) antagonists, but not typical APDs, eg, haloperidol, reverses the PCP-induced NOR deficit in rats. We have tested the ability of lurasidone, an atypical APD with potent 5-HT(1A) partial agonist properties, tandospirone, a selective 5-HT(1A) partial agonist, haloperidol, a D(2) antagonist, and pimavanserin, a 5-HT(2A) inverse agonist, to prevent the development of the PCP-induced NOR deficit. Rats were administered lurasidone (0.1 or 1 mg/kg), tandospirone (5 mg/kg), pimavanserin (3 mg/kg), or haloperidol (1 mg/kg) b.i.d. 30 min before PCP (2 mg/kg, b.i.d.) for 7 days (day1-7), followed by a 7-day washout (day 8-14). Subchronic treatment with PCP induced an enduring NOR deficit. Lurasidone (1 mg/kg) but not 0.1 mg/kg, which is effective to acutely reverse the deficit due to subchronic PCP, or tandospirone, but not pimavanserin or haloperidol, significantly prevented the PCP-induced NOR deficit on day 15. The ability of lurasidone co-treatment to prevent the PCP-induced NOR deficit was enduring and still present at day 22. The preventive effect of lurasidone was blocked by WAY100635, a selective 5-HT(1A) antagonists, further evidence for the importance of 5-HT(1A) receptor stimulation in the NOR deficit produced by subchronic PCP. Further study is needed to determine whether these results concerning mechanism and dosage can be the basis for prevention of the development of CIS in at risk populations.

Topics: Animals; Cognition Disorders; Disease Models, Animal; Dopamine D2 Receptor Antagonists; Female; Haloperidol; Isoindoles; Lurasidone Hydrochloride; Phencyclidine; Piperazines; Piperidines; Pyridines; Pyrimidines; Rats; Rats, Long-Evans; Receptors, N-Methyl-D-Aspartate; Schizophrenia; Serotonin 5-HT1 Receptor Agonists; Serotonin 5-HT1 Receptor Antagonists; Serotonin 5-HT2 Receptor Agonists; Thiazoles; Urea

Topics: Akathisia, Drug-Induced; Antipsychotic Agents; Aripiprazole; Basal Ganglia Diseases; Dopamine Agonists; Dopamine Antagonists; Dose-Response Relationship, Drug; Humans; Piperazines; Piperidines; Positron-Emission Tomography; Psychomotor Agitation; Quinolones; Receptor, Serotonin, 5-HT1A; Receptors, Dopamine D2; Schizophrenia; Serotonin 5-HT1 Receptor Agonists; Urea