Dopamine D2 receptor occupancy of lumateperone (ITI-007): a Positron Emission Tomography Study in patients with schizophrenia

Analysis of lumateperone data for patients with schizophrenia using related adverse events from the FDA adverse reporting system

BACKGROUND

Our study utilized the U.S. Food and Drug Administration's Adverse Event Reporting System (FAERS) to analyze and study the adverse event (AEs) signals of second-generation antipsychotic drug lumateperone, providing a reference for clinical safety monitoring in the treatment of schizophrenia.

METHODS

The International Dictionary of Medical Terminology (version 26.0) was used to standardize the preferred system organ category (SOC) and preferred terminology (PT) for adverse drug events (ADE) data related to lumateperone. ADE signals were classified and described using four algorithms: reporting odds ratios (ROR), proportional reporting ratios (PRR), Bayesian confidence-propagation neural network (BCPNN) and Multinomial gamma-poisson shrinkage (MGPS).

RESULT

Among the 2542 case reports collected from the FAERS database, 1762 reports with lumateperone as a 'principal suspect(PS)' AEs were identified. Lumateperone-induced AEs occurred in 26 system organ categories (SOC). A total of 118 significant disproportionate preferred terms (PTs) meeting the requirements of 4 algorithms were retained, and unexpected major events, such as burning sensation, tremor, migraine etc. may also occur. The median time to onset of lumateperone-related adverse events was 9 days (interquartile range [IQR] 2-31.25 days), and most AEs occurred within the first 10 days and 1 month after initiation of lumateperone therapy.

CONCLUSION

Our research may provide a better understanding of the potential adverse events that may be caused by lumateperone and those not recorded in the drug instructions, providing valuable signals for clinical use.

Pharmacodynamic properties of lumateperone and its efficacy in acute bipolar depression: a mechanistic hypothesis based on data

The treatment of bipolar depression is one of the most challenging needs in contemporary psychiatry. Currently, only quetiapine, olanzapine-fluoxetine combination, lurasidone, cariprazine, and recently lumateperone have been FDA-approved to treat this condition. The neurobiology of bipolar depression and the possible mechanistic targets of bipolar antidepressant therapy remain elusive. The current study investigated whether the pharmacodynamic properties of lumateperone fit into a previously developed model which was the first to be derived based on the strict combination of clinical and preclinical data. The authors performed a systematic review of the literature to identify the pharmacodynamic properties of lumateperone. The original model suggests that a constellation of effects on different receptors is necessary, but refinements, including the present study, suggest that the inhibition of the serotonin reuptake at the first level, the 5HT-2A blockade at the second level, and the norepinephrine alpha-1 receptors blockade at a third level in combination with D1 blockade contribute to the antidepressant effect in acute bipolar depression. The D2 blockade acts as a protective mechanism and reduces the risk of switching to mania/hypomania.

The Novel Antipsychotic Lumateperone (Iti-007) in the Treatment of Schizophrenia: A Systematic Review

Lumateperone (also known as ITI-007 or ITI-722) represents a novel second-generation medication characterized by a favorable safety and tolerability profile. This is attributed to its notable selectivity for D2 receptors within specific regions of the brain. The U.S. Food and Drug Administration (FDA) granted approval for the treatment of schizophrenia in adults in December 2019. Additionally, it gained approval for addressing depressive episodes associated with bipolar I and II disorders in adults, either as a standalone therapy or in conjunction with lithium or valproate, in December 2021. The objective of this investigation is to systematically review the existing literature to assess the safety, tolerability, and efficacy of lumateperone in the treatment of schizophrenia. Lumateperone has demonstrated effectiveness in addressing positive, negative, and cognitive symptoms associated with schizophrenia. The evaluation of safety indicators in the reviewed studies indicates that lumateperone is deemed to be a well-tolerated and safe antipsychotic. Additional research is warranted to explore lumateperone's efficacy in managing major depressive disorders, behavioral issues in Alzheimer's disease and dementia, sleep maintenance insomnia, bipolar disorders, and personality disorders.

Adjunctive lumateperone (ITI-007) in the treatment of bipolar depression: Results from a randomized placebo-controlled clinical trial

OBJECTIVE

This phase 3, randomized, double-blind, placebo-controlled study (NCT02600507) evaluated the efficacy and safety of lumateperone adjunctive therapy to lithium or valproate in patients with bipolar depression.

METHODS

Patients (18-75 years) with bipolar I or bipolar II disorder experiencing a major depressive episode (MDE), with inadequate therapeutic response to lithium or valproate, were randomized 1:1:1 to 6 weeks adjunctive therapy with lumateperone 28 mg (n = 176), lumateperone 42 mg (n = 177), or placebo (n = 176). The primary and key secondary efficacy endpoints were change from baseline to Day 43 in Montgomery-Åsberg Depression Rating Scale (MADRS) Total score and the Clinical Global Impression Scale-Bipolar Version-Severity Scale (CGI-BP-S) depression subscore. Safety assessments included adverse events, laboratory evaluations, vital signs, extrapyramidal symptoms (EPS), and suicidality.

RESULTS

Patients treated with adjunctive lumateperone 42 mg showed significantly greater improvement compared with adjunctive placebo in MADRS Total score (LS mean difference vs placebo [LSMD], -2.4; p = 0.02) and CGI-BP-S depression subscore (LSMD, -0.3; p = 0.01), while adjunctive lumateperone 28 mg showed numerical improvement in MADRS Total score (LSMD, -1.7; p = 0.10) and improvement in the CGI-BP-S depression subscore (LSMD, -0.3; p = 0.04). Adjunctive lumateperone treatment was well tolerated; treatment-emergent adverse events reported at rates >5% and twice placebo for lumateperone 42 mg were somnolence (11.3%), dizziness (10.7%), and nausea (8.5%), with minimal risk of EPS, metabolic abnormalities, or increased prolactin.

CONCLUSIONS

Lumateperone 42-mg treatment adjunctive to lithium or valproate significantly improved depression symptoms and was generally well tolerated in patients with MDEs associated with either bipolar I or bipolar II disorder.

Antipsychotic dose, dopamine D2 receptor occupancy and extrapyramidal side-effects: a systematic review and dose-response meta-analysis

Antipsychotic drugs differ in their propensity to cause extrapyramidal side-effects (EPS), but their dose-effects are unclear. Therefore, we conducted a systematic review and dose-response meta-analysis. We searched multiple electronic databases up to 20.02.2023 for fixed-dose studies investigating 16 second-generation antipsychotics and haloperidol (all formulations and administration routes) in adults with acute exacerbations of schizophrenia. The primary outcome was the number of participants receiving antiparkinsonian medication, and if not available, the number of participants with extrapyramidal side-effects (EPS) and the mean scores of EPS rating scales were used as proxies. The effect-size was odds ratio (ORs) compared with placebo. One-stage random-effects dose-response meta-analyses with restricted cubic splines were conducted to estimate the dose-response curves. We also examined the relationship between dopamine D2 receptor (D2R) occupancy and ORs by estimating occupancies from administrated doses. We included data from 110 studies with 382 dose arms (37193 participants). Most studies were short-term with median duration of 6 weeks (range 3-26 weeks). Almost all antipsychotics were associated with dose-dependent EPS with varied degrees and the maximum ORs ranged from OR = 1.57 95%CI [0.97, 2.56] for aripiprazole to OR = 7.56 95%CI [3.16, 18.08] for haloperidol at 30 mg/d. Exceptions were quetiapine and sertindole with negligible risks across all doses. There was very low quality of findings for cariprazine, iloperidone, and zotepine, and no data for clozapine. The D2R occupancy curves showed that the risk increased substantially when D2R occupancy exceeded 75-85%, except for D2R partial agonists that had smaller ORs albeit high D2R occupancies. In conclusion, we found that the risk of EPS increases with rising doses and differs substantially in magnitude among antipsychotics, yet exceptions were quetiapine and sertindole with negligible risks. Our data provided additional insights into the current D2R therapeutic window for EPS.

Evaluating lumateperone for its use in treating depressive episodes associated with bipolar I or II disorder in adults

INTRODUCTION

Lumateperone is a novel antipsychotic medication that has recently received approval by the United States Food and Drug Administration for treatment of major depressive episodes of type I and II bipolar disorder. It is approved for use as monotherapy or as an adjunctive treatment to lithium or valproic acid.

AREAS COVERED

Clinical trials performed with lumateperone for bipolar disorder were reviewed. Additionally, pharmacodynamic actions of lumateperone are reviewed. Lumateperone is superior to placebo whether used alone or in combination with a mood stabilizer in patients with type I or type II bipolar disorder. It achieves this effect with minimal dopamine blockade-related side effects due to less than 50% dopamine D2 receptor occupancy. While the pharmacodynamic profile of lumateperone is unique, the mechanism of action in bipolar depression remains obscure.

EXPERT OPINION

Lumateperone is an antipsychotic with full antagonist effects at the post-synaptic D2, and partial agonist effects at the presynaptic D2. This unique profile allows for both antipsychotic and antidepressant effects at the same dose, which does not produce dopamine-related side effects. Consequently, lumateperone is exceptionally well tolerated compared to other antidepressant-acting antipsychotic agents. It is now the only agent approved as an adjunct to the mood stabilizer for bipolar II depression.

Mechanistic Study on CpRh(III)-Catalyzed [3 + 2] Annulation of Aniline Derivatives with Vinylsilanes: A DFT Study

The rhodium(III)-catalyzed reaction of aniline derivatives that contain a pyrimidine-directing group with vinylsilanes results in the formation of C3-substituted indoline derivatives. The reaction path and formation of the indoline product with density functional theory calculations were analyzed. This study reveals that the whole catalysis can be characterized in the following stages: (I) C-H activation via concerted metalation deprotonation, (II) 2,1-vinylsilane insertion, (III) deprotonation of the NH amide proton, (IV) the oxidation of Ag⁺, and (V) reductive elimination. These steps are kinetically and thermodynamically feasible for experimental realization under mild conditions, and the insertion step with a barrier of 22.0 kcal/mol should not only be the critical step of regioselectivity but also the rate-determining step during the whole catalysis. Computations reveal that the Ag⁺ oxidation can accelerate the reductive elimination step after the formation of natural intermediate, thus highlighting the role of Ag⁺ as a catalytic promoter for the oxidatively induced reactivity of the Rh catalyst in C3-substituted indoline synthesis.

Asymmetric Synthesis of US-FDA Approved Drugs over Five Years (2016–2020): A Recapitulation of Chirality

Chirality is a major theme in the design, discovery, and development of new drugs. Historically, pharmaceuticals have been synthesized as racemic mixtures. However, the enantiomeric forms of drug molecules have distinct biological properties. One enantiomer may be responsible for the desired therapeutic effect (eutomer), whereas the other may be inactive, interfere with the therapeutic form, or exhibit toxicity (distomer). Classical chemical synthesis usually leads to a racemic mixture unless stereospecific synthesis is employed. To meet the requirements of single-enantiomeric drugs, asymmetric synthesis has evolved at the forefront of drug discovery. Asymmetric synthesis involves the conversion of an achiral starting material into a chiral product. This review emphasizes the methods used for synthesizing FDA-approved chiral drugs during 2016–2020, with a special focus on asymmetric synthesis by means of chiral induction, resolution, or chiral pool.

Seventy Years of Antipsychotic Development: A Critical Review

Since the mid-1950s discovery of the first effective antipsychotic medications (APM), we have only been able to improve the tolerability but not the overall efficacy of currently available APMs, as reflected by effectiveness trials in Europe and the United States. This inability to develop more effective APMs is attributable to multiple factors, including failure to create and use assessment tools to assess core symptom domains in schizophrenia, move beyond the dopaminergic hypothesis and to develop "me too" drugs, imposing ill-defined research domain criteria, and lacking federal funding for clinical trials. The classification of APMs is also confusing, including second-generation, partial agonists, and multimodal APMs in the same class of APMs, despite significant differences in their mechanisms of action. Other factors stagnating drug development include inadequate sample sizes to address heterogeneity, lack of statistical measures correlating with clinical significance, using the atheoretical basis of psychiatric diagnoses, failure to control placebo response, and high cost of newer and perhaps more tolerable APMs. Furthermore, there has been a failure to develop early predictors of antipsychotic response and various tools to optimize an APM response. Finally, some mental health providers are also responsible for the suboptimal use of APMs, by using excessive maintenance doses, often with irrational polypharmacy, further compromising effectiveness and medication adherence. However, some bright spots in antipsychotic development include improved tolerability of APMs and long-acting injectables to address the high prevalence of medication nonadherence. This review critically reviews 70 years of antipsychotic development, the reasons behind the failure to develop more effective APMs, and suggestions for future direction.

Lumateperone for the Treatment of Adults With Schizophrenia: a Systematic Review

PURPOSE OF REVIEW

Lumateperone (LUM) is the U.S. Food and Drug Administration approved atypical antipsychotic agent for adults with schizophrenia (SCZ) and bipolar depression (for both bipolar I and bipolar II disorder as as monotherapy or as adjunctive treatment to lithium or valproate). LUM simultaneously modulates serotonin, dopamine, and glutamate neurotransmission. The foregoing pleiotropic mechanism of action is predictive of therapeutic benefits across multiple domains of psychopathology in SCZ (i.e., positive, negative, cognitive, and prosocial symptoms). Herein, the overarching aim is to synthesize the extant literature reporting on the efficacy, safety, and tolerability of LUM in adults with SCZ.

RECENT FINDINGS

Four clinical studies (i.e., three RCTs and one open-label trial) were included in this synthesis. Overall, LUM significantly reduced the severity of SCZ compared with placebo. The open label study provided the real-world effectiveness of shifting stable patients with SCZ to LUM from other atypical antipsychotics. With respect to safety and tolerability profile, LUM demonstrated placebo-level rates of weight gain, metabolic shift, prolactin elevation, extrapyramidal side effects (EPS), and akathisia across short term trials (i.e., 4-6 weeks). Taken together, our results indicate that LUM significantly improves symptoms severity in adults with SCZ. LUM also exhibits a favorable tolerability and safety profile with placebo level rates of weight gain, metabolic disruption, akathisia, extrapyramidal side effects (excluding akathisia), and prolactin elevation. Lumateperone should be conceptualized as a first-line treatment strategy for adults with SCZ.

Enantioselective synthesis of cis-hexahydro-γ-carboline derivatives via Ir-catalyzed asymmetric hydrogenation

A novel synthetic route was developed for the construction of a chiral cis-hexahydro-γ-carboline derivative through Ir/ZhaoPhos-catalyzed asymmetric hydrogenation of corresponding tetrahydro-γ-carboline with high yields (up to 99% yield), excellent diastereoselectivities (up to >99 : 1 dr) and enantioselectivities (up to 99% ee), and high substrate-to-catalyst ratios (up to 5000).

Population Pharmacokinetic Modeling and Simulation of TV-46000: A Long-Acting Injectable Formulation of Risperidone

TV‐46000 is a long‐acting subcutaneous antipsychotic that uses a novel copolymer drug delivery technology in combination with a well‐characterized molecule, risperidone, that is in clinical development as a treatment for schizophrenia. A population pharmacokinetic (PPK) modeling and simulation approach was implemented to identify TV‐46000 doses and dosing schedules for clinical development that would provide the best balance between clinical efficacy and safety. The PPK model was created by applying pharmacokinetic data from a phase 1 study of 97 patients with a diagnosis of schizophrenia or schizoaffective disorder who received either single or repeated doses of TV‐46000. The PPK model was used to characterize the complex release profile of the total active moiety (TAM; the sum of the risperidone and 9‐OH risperidone concentrations) concentration following subcutaneous injections of TV‐46000. The PK profile was best described by a double Weibull function of the in vivo release rate and by a 2‐compartment disposition and elimination model. Simulations were performed to determine TV‐46000 doses and dosing schedules that maintained a median profile of TAM concentrations similar to published TAM exposure following oral risperidone doses that have been correlated to a 40% to 80% dopamine‐D2 receptor occupancy therapeutic window. The simulations showed that therapeutic dose ranges for TV‐46000 are 50 to 125 mg for once‐monthly and 100 to 250 mg for the once every 2 months regimens. This PPK model provided a basis for prediction of patient‐specific exposure and dopamine‐D2 receptor occupancy estimates to support further clinical development and dose selection for the phase 3 studies.

Structure-based discovery of nonhallucinogenic psychedelic analogs

Drugs that target the human serotonin 2A receptor (5-HT_2AR) are used to treat neuropsychiatric diseases; however, many have hallucinogenic effects, hampering their use. Here, we present structures of 5-HT_2AR complexed with the psychedelic drugs psilocin (the active metabolite of psilocybin) and d-lysergic acid diethylamide (LSD), as well as the endogenous neurotransmitter serotonin and the nonhallucinogenic psychedelic analog lisuride. Serotonin and psilocin display a second binding mode in addition to the canonical mode, which enabled the design of the psychedelic IHCH-7113 (a substructure of antipsychotic lumateperone) and several 5-HT_2AR β-arrestin-biased agonists that displayed antidepressant-like activity in mice but without hallucinogenic effects. The 5-HT_2AR complex structures presented herein and the resulting insights provide a solid foundation for the structure-based design of safe and effective nonhallucinogenic psychedelic analogs with therapeutic effects.

Present and future antipsychotic drugs: a systematic review of the putative mechanisms of action for efficacy and a critical appraisal under a translational perspective

Antipsychotics represent the mainstay of schizophrenia pharmacological therapy, and their role has been expanded in the last years to mood disorders treatment. Although introduced in 1952, many years of research were required before an accurate picture of how antipsychotics work began to emerge. Despite the well-recognized characterization of antipsychotics in typical and atypical based on their liability to induce motor adverse events, their main action at dopamine D2R to elicit the "anti-psychotic" effect, as well as the multimodal action at other classes of receptors, their effects on intracellular mechanisms starting with receptor occupancy is still not completely understood. Significant lines of evidence converge on the impact of these compounds on multiple molecular signaling pathways implicated in the regulation of early genes and growth factors, dendritic spine shape, brain inflammation, and immune response, tuning overall the function and architecture of the synapse. Here we present, based on PRISMA approach, a comprehensive and systematic review of the above mechanisms under a translational perspective to disentangle those intracellular actions and signaling that may underline clinically relevant effects and represent potential targets for further innovative strategies in antipsychotic therapy.

New and emerging treatments for schizophrenia: a narrative review of their pharmacology, efficacy and side effect profile relative to established antipsychotics

Schizophrenia is associated with substantial unmet needs, highlighting the necessity for new treatments. This narrative review compares the pharmacology, clinical trial data and tolerability of novel medications to representative antipsychotics. Cariprazine, brexpiprazole and brilaroxazine are partial dopamine agonists effective in acute relapse. Lumateperone (serotonin and dopamine receptor antagonist) additionally benefits asocial and depressive symptoms. F17464 (D3 antagonist and 5-HT1A partial agonist) has one positive phase II study. Lu AF35700 (dopamine and serotonin receptor antagonist) was tested in treatment-resistance with no positive results. Pimavanserin, roluperidone, ulotaront and xanomeline do not act directly on the D2 receptor at clinical doses. Initial studies indicate pimavanserin and roluperidone improve negative symptoms. Ulotaront and xanomeline showed efficacy for positive and negative symptoms of schizophrenia in phase II trials. BI 409306, BI 425809 and MK-8189 target glutamatergic dysfunction in schizophrenia, though of these only BI 425809 showed efficacy. These medications largely have favourable cardiometabolic side-effect profiles. Overall, the novel pharmacology, clinical trial and tolerability data indicate these compounds are promising new additions to the therapeutic arsenal.

Newer antipsychotics: Brexpiprazole, cariprazine, and lumateperone: A pledge or another unkept promise?

Antipsychotic agents are used for various indications in the treatment of psychiatric disorders. Despite their proven roles in multiple conditions, the treatment-emergent side effects of antipsychotic medications, such as metabolic side effects, are often the limiting factor for their long-term and short-term uses. Moreover, antipsychotic medications are often criticized for being less effective in treating different disabling symptoms such as negative symptoms of schizophrenia. As a result, the search for safer and more efficacious antipsychotic agents is ongoing. Newer antipsychotic agents are gaining attention related to emerging efficacy and tolerability data in treating neuropsychiatric conditions. In this review, we attempt to appraise the scientific data on psychopharmacology, safety profile, and efficacy of the newer additions to the list of second-generation antipsychotics, namely brexpiprazole, cariprazine, and lumateperone. We conducted a selective review utilizing PubMed, clinicaltrials.gov, and Cochrane databases to gather appropriate publications, keeping broad inclusion criteria. There were no restrictions on the age of the study population or the year of publication. We also cross-referenced articles and references to capture all existing studies. Our review of the current literature indicates that all three antipsychotic agents appear to be promising based on their short-term studies, while long-term studies remain limited. There is also a need for a head to head comparison between the newer antipsychotics with the other antipsychotic agents to ascertain if the newer agents are any better than the others.

New Antipsychotic Medications in the Last Decade

PURPOSE OF REVIEW

Over the last ten years, the treatment of psychosis has seen a near explosion of creative development in both novel agents and new delivery modalities. The current review summarizes these developments over the past decade (2011-2020). We performed a systematic review utilizing PubMed and PsychInfo with the aim of identifying all the RCT and related analyses in adults with psychosis (schizophrenia and mania).

RECENT FINDINGS

We identified 11 significant developments: the introduction of new antipsychotics cariprazine, brexpiprazole, lumateperone, and pimavanserin; introduction of new delivery methods: subcutaneous long-acting risperidone, aripiprazole lauroxil, transdermal asenapine, and inhaled loxapine; and the introduction of new approaches such as olanzapine/samidorphan for olanzapine-associated weight gain, examination of the TAAR1 agonist SEP 363,856 as a test of concept, and the combination of Xanomeline/Trospium, an M₁ and M₄ muscarinic receptor agonist in conjunction with a peripheral anticholinergic. Last decade has seen a tremendous development in second-generation antipsychotics which provides unprecedented treatment options for clinicians in treating psychosis.

Lumateperone tosylate, A Selective and Concurrent Modulator of Serotonin, Dopamine, and Glutamate, in the Treatment of Schizophrenia

Purpose of Review

This is a comprehensive review of the literature regarding the use of Lumateperone tosylate for schizophrenia. This review presents the background, evidence, and indications for the use of lumateperone tosylate in the treatment of schizophrenia.

Recent Findings

Schizophrenia is a chronic mental health disorder that affects approximately 3.3 million people in the United States. Its symptoms, which must be present more than six months, are comprised of disorganized behavior and speech, a diminished capacity to comprehend reality, hearing voices unheard by others, seeing things unseen by others, delusions, decreased social commitment, and decreased motivation. The majority of these symptoms can be managed with antipsychotic medication. Lumateperone is a selective and concurrent modulator of serotonin, dopamine, and glutamate, which all mediate or modulate serious mental illness.

Summary

Schizophrenia is a complex, severe mental illness that affects how the brain processes information. There are many medications used to treat schizophrenia. One antipsychotic agent, lumateperone tosylate, is a newer agent that the FDA recently approved. The most common adverse effects are shown to be mild such as somnolence, constipation, sedation, and fatigue, with the 42 mg recommended dose. Lumateperone tosylate is an FDA-approved drug that can be given only at the 42mg dose once daily with no titration requirements.

Trace Amine-Associated Receptor 1 as a Target for the Development of New Antipsychotics: Current Status of Research and Future Directions

Schizophrenia is a mental illness associated with an array of symptoms that often result in disability. The primary treatments for schizophrenia are termed antipsychotics. Although antipsychotics modulate a number of different receptor types and subtypes, all currently regulatory agency-approved antipsychotics share in common direct or functional antagonism at the dopamine type 2 receptor (D₂R). The majority of people with schizophrenia do not achieve full resolution of their symptoms with antipsychotics, suggesting the need for alternative or complementary approaches. The primary focus of this review is to assess the evidence for the role of the trace amine-associated receptor 1 (TAAR-1) in schizophrenia and the role of TAAR-1 modulators as novel-mechanism antipsychotics. Topics include an overview of TAAR-1 physiology and pathophysiology in schizophrenia, interaction with other neurotransmitter systems, including the dopaminergic, glutamatergic and serotonergic system, and finally, a review of investigational TAAR-1 compounds that have reached Phase II clinical studies in schizophrenia: SEP-363856 (ulotaront) and RO6889450 (ralmitaront). Thus far, results are publicly available only for ulotaront in a relatively young (18-40 years) and acutely exacerbated cohort. These results showed positive effects for overall schizophrenia symptoms without significant tolerability concerns. An ongoing study of ralmitaront will assess specific efficacy in patients with persistent negative symptoms. If trials of TAAR-1 modulators, and other novel-mechanism targets for schizophrenia that are under active study, continue to show positive results, the definition of an antipsychotic may need to be expanded beyond the D₂R target in the near future.

Contrasting Typical and Atypical Antipsychotic Drugs

The beliefs that antipsychotic drugs (APDs) are 1) effective only to treat delusions and hallucinations (positive symptoms), 2) that typical and atypical APDs differ only in ability to cause extrapyramidal side effects, and 3) that their efficacy as antipsychotics is due solely to their dopamine D₂ receptor blockade are outmoded concepts that prevent clinicians from achieving optimal clinical results when prescribing an APD. Atypical APDs are often more effective than typical APDs in treating negative symptoms, cognitive impairment, and mood symptoms as well as reducing the risk for suicide and decreasing aggression. This applies not only to those diagnosed with schizophrenia or schizoaffective disorder but also to bipolar disorder, major depression, and other psychiatric diagnoses. The greater advantage of an atypical APD is not evident in all patients for every atypical APD due, in part, to individual differences in genetic and epigenetic endowment and differences in the pharmacology of the atypical APDs, their mode of action being far more complex than that of the typical APDs. A common misconception is that among the atypical APDs, only clozapine is effective for reducing psychosis in treatment-resistant schizophrenia. Aripiprazole, lurasidone, olanzapine, and risperidone also can be more effective than typical APDs for treatment-resistant schizophrenia; clozapine is uniquely indicated for reducing the risk for suicide. The ability of the atypical APDs to improve cognition and negative symptoms in some patients together with lower propensity to cause tardive dyskinesia (an underappreciated advantage) leads to better overall outcomes. These advantages of the atypical APDs in efficacy and safety are due, in part, to initiation of synaptic plasticity via direct and indirect effects of the atypical APDs on a variety of proteins, especially G proteins, and release of neurotrophins (e.g., brain-derived neurotrophic factor). The typical APDs beneficial effects on psychosis are mainly the result of D₂ receptor blockade, which can be associated with serious side effects and lack of tolerability.

Evidence on the New Drug Lumateperone (ITI-007) for Psychiatric and Neurological Disorders

Lumateperone (ITI-007) is a tosylate salt with binding affinities to receptors implicated in the therapeutic actions of antipsychotic medications, including the serotonin 5HT2A receptors, dopamine D2 and D1 receptors and the serotonin transporter. It has a unique mechanism of action because it simultaneously modulates serotonin, dopamine, and glutamate neurotransmission, implicated in serious mental illness. It can be considered a multi-target-directed ligand and a multifunctional modulator of serotoninergic system with possible precognitive, antipsychotic, antidepressant and anxiolytic properties. Lumateperone has been investigated as a novel agent for the treatment of schizophrenia, but it represents a new potential option for other psychiatric and neurological diseases, such as behavioural symptoms of dementia or Alzheimer's disease, sleep disturbances, bipolar depression. Besides, it has demonstrated a favourable safety profile without significant extrapyramidal side effects, hyperprolactinemia or changes in cardiometabolic or endocrine factors versus placebo. Additional studies are warranted to confirm and examine the benefit of lumateperone and possible therapeutic targets. This paper is a comprehensive and thorough summary of the most important findings and potential future role of this particular compound in personalized treatments.

Spatially constrained kinetic modeling with dual reference tissues improves 18F-flortaucipir PET in studies of Alzheimer disease

PURPOSE

Recent studies have shown that standard compartmental models using plasma input or the cerebellum reference tissue input are generally not reliable for quantifying tau burden in dynamic 18F-flortaucipir PET studies of Alzheimer disease. So far, the optimal reference region for estimating 18F-flortaucipir delivery and specific tau binding has yet to be determined. The objective of the study is to improve 18F-flortaucipir brain tau PET quantification using a spatially constrained kinetic model with dual reference tissues.

METHODS

Participants were classified as either cognitively normal (CN) or cognitively impaired (CI) based on clinical assessment. T1-weighted structural MRI and 105-min dynamic 18F-flortaucipir PET scans were acquired for each participant. Using both a simplified reference tissue model (SRTM2) and Logan plot with either cerebellum gray matter or centrum semiovale (CS) white matter as the reference tissue, we estimated distribution volume ratios (DVRs) and the relative transport rate constant R1 for region of interest-based (ROI) and voxelwise-based analyses. Conventional linear regression (LR) and LR with spatially constrained (LRSC) parametric imaging algorithms were then evaluated. Noise-induced bias in the parametric images was compared to estimates from ROI time activity curve-based kinetic modeling. We finally evaluated standardized uptake value ratios at early phase (SUVREP, 0.7-2.9 min) and late phase (SUVRLP, 80-105 min) to approximate R1 and DVR, respectively.

RESULTS

The percent coefficients of variation of R1 and DVR estimates from SRTM2 with spatially constrained modeling were comparable to those from the Logan plot and SUVRs. The SRTM2 using CS reference tissue with LRSC reduced noise-induced underestimation in the LR generated DVR images to negligible levels (< 1%). Inconsistent overestimation of DVR in the SUVRLP only occurred using the cerebellum reference tissue-based measurements. The CS reference tissue-based DVR and SUVRLP, and cerebellum-based SUVREP and R1 provided higher Cohen's effect size d to detect increased tau deposition and reduced relative tracer transport rate in CI individuals.

CONCLUSION

Using a spatially constrained kinetic model with dual reference tissues significantly improved quantification of relative perfusion and tau binding. Cerebellum and CS are the suggested reference tissues to estimate R1 and DVR, respectively, for dynamic 18F-flortaucipir PET studies. Cerebellum-based SUVREP and CS-based SUVRLP may be used to simplify 18F-flortaucipir PET study.

The role of lumateperone in the treatment of schizophrenia

Schizophrenia is a devastating mental disorder resulting in marked morbidity and mortality despite the optimal use of all currently available interventions. For this reason, the release of lumateperone (CaptylaR), also known as ITI-007, an orally administered, atypical antipsychotic provided a welcome novel tool for clinicians to utilize precision medicine to tailor an optimal treatment plan to the specific needs of each person with schizophrenia. To generate a foundation for clinicians to assess the risks and benefits of lumateperone in relation to other interventions for schizophrenia, we conducted a search of items for 'ITI-007' and 'lumateperone' on PubMed, ScienceDirect, Web of Science, Google Scholar, and www.clinicaltrials.gov. We present a critical evaluation of the limited information about lumateperone for schizophrenia, its use approved by the US Food and Drug Administration. Lumateperone merits consideration for patients with treatment-resistant schizophrenia and for patients with schizophrenia who are vulnerable to developing metabolic dysfunction and movement disorders. On the other hand, lumateperone should not be used for (a) women who are pregnant or breastfeeding, children, adolescents, and elderly patients with dementia-related psychosis, (b) patients who are at risk for cerebrovascular diseases, (c) patients who use inducers and moderate or strong inhibitors of the cytochrome P450-3A4 (CYP3A4) isozyme, and (d) patients who use alcohol and other sedating agents. Clinical trials from multiple centers without financial conflicts of interest to market lumateperone are needed to directly compare and contrast lumateperone and other antipsychotic agents to generate trustworthy evidence to be assessed objectively by clinicians treating patients with schizophrenia. Future investigations will provide the foundations to identify the evidence for comprehensive evaluations of the role of lumateperone in the treatment of people with schizophrenia and other conditions.

TPN672: A Novel Serotonin-Dopamine Receptor Modulator for the Treatment of Schizophrenia

TPN672 [7-(2-(4-(benzothiophen-4-yl) piperazin-1-yl)ethyl)quinolin-2(1H)-one maleate] is a novel antipsychotic candidate with high affinity for serotonin and dopamine receptors that is currently in clinical trial for the treatment of psychiatric disorders. In vitro binding study showed that TPN672 exhibited extremely high affinity for serotonin 1A receptor (5-HT_1AR) (K _i = 0.23 nM) and 5-HT_2AR (K _i = 2.58 nM) as well as moderate affinity for D₃R (K _i = 11.55 nM) and D₂R (K _i = 17.91 nM). In vitro functional assays demonstrated that TPN672 acted as a potent 5-HT_1AR agonist, D₂R/D₃R partial agonist, and 5-HT_2AR antagonist. TPN672 displayed robust antipsychotic efficacy in rodent models (e.g., blocking phencyclidine-induced hyperactivity), significantly better than aripiprazole, and ameliorated negative symptoms and cognitive deficits in the sociability test, dark avoidance response, Morris water maze test, and novel object recognition test. The results of electrophysiological experiments showed that TPN672 might inhibit the excitability of the glutamate system through activating 5-HT_1AR in medial prefrontal cortex, thereby improving cognitive and negative symptoms. Moreover, the safety margin (the ratio of minimum catalepsy-inducing dose to minimum effective dose) of TPN672 was about 10-fold, which was superior to aripiprazole. In conclusion, TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having lower risk of extrapyramidal symptoms and hyperprolactinemia. SIGNIFICANCE STATEMENT: TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having a lower risk of extrapyramidal symptoms and hyperprolactinemia. A phase I clinical trial is now under way to test its tolerance, pharmacokinetics, and pharmacodynamic effects in human volunteers. Accordingly, the present results will have significant impact on the development of new antischizophrenia drugs.

Lessons learned from using fMRI in the early clinical development of a mu-opioid receptor antagonist for disorders of compulsive consumption

Functional magnetic resonance imaging (fMRI) has been widely used to gain a greater understanding of brain circuitry abnormalities in CNS disorders. fMRI has also been used to examine pharmacological modulation of brain circuity and is increasingly being used in early clinical drug development as functional pharmacodynamic index of target engagement, and to provide early indication of clinical efficacy. In this short review, we summarize data from experimental medicine and early clinical development studies of a mu-opioid receptor antagonist, GSK1521498 developed for disorders of compulsive consumption including binge eating in obesity. We demonstrate how fMRI can be used to answer important questions of early clinical drug development relating to; (1) target engagement, (2) dose response relationships, (3) differential efficacy and (4) prediction of behavioural and clinically relevant outcomes. We also highlight important methodological factors that need to be considered when conducting fMRI studies in drug development given the challenges faced with small sample sizes in Phase 1 and early proof of mechanism studies. While these data highlight the value of fMRI as a biomarker in drug development, its use for making Go/No-go decisions is still faced with challenges given the variability of responses, interpretation of brain activation changes and the limited data linking drug induced changes in brain activity to clinical or behavioural outcome. These challenges need to be addressed to fulfil the promise of fMRI as a tool in clinical drug development.

In Vivo Receptor Visualization and Evaluation of Receptor Occupancy with Positron Emission Tomography

Positron emission tomography (PET) is useful for noninvasive in vivo visualization of disease-related receptors, for evaluation of receptor occupancy to determine an appropriate drug dosage, and for proof-of-concept of drug candidates in translational research. For these purposes, the specificity of the PET tracer for the target receptor is critical. Here, we review work in this area, focusing on the chemical structures of reported PET tracers, their K_i/K_d values, and the physical properties relevant to target receptor selectivity. Among these physical properties, such as cLogP, cLogD, molecular weight, topological polar surface area, number of hydrogen bond donors, and pK_a, we focus especially on LogD and LogP as important physical properties that can be easily compared across a range of studies. We discuss the success of PET tracers in evaluating receptor occupancy and consider likely future developments in the field.

Beyond Dopamine Receptor Antagonism: New Targets for Schizophrenia Treatment and Prevention

Treatment of schizophrenia (SCZ) historically relies on the use of antipsychotic drugs to treat psychosis, with all of the currently available antipsychotics acting through the antagonism of dopamine D2 receptors. Although antipsychotics reduce psychotic symptoms in many patients, they induce numerous undesirable effects and are not effective against negative and cognitive symptoms. These highlight the need to develop new drugs to treat SCZ. An advanced understanding of the circuitry of SCZ has pointed to pathological origins in the excitation/inhibition balance in regions such as the hippocampus, and restoring function in this region, particularly as a means to compensate for parvalbumin (PV) interneuron loss and resultant hippocampal hyperactivity, may be a more efficacious approach to relieve a broad range of SCZ symptoms. Other targets, such as cholinergic receptors and the trace amine-associated receptor 1 (TAAR1), have also shown some promise for the treatment of SCZ. Importantly, assessing efficacy of novel compounds must take into consideration treatment history of the patient, as preclinical studies suggest prior antipsychotic treatment may interfere with the efficacy of these novel agents. However, while novel therapeutic targets may be more effective in treating SCZ, a more effective approach would be to prevent the transition to SCZ in susceptible individuals. A focus on stress, which has been shown to be a predisposing factor in risk for SCZ, is a possible avenue that has shown promise in preclinical studies. Therefore, therapeutic approaches based on our current understanding of the circuitry of SCZ and its etiology are likely to enable development of more effective therapeutic interventions for this complex disorder.

Safety and tolerability of lumateperone 42 mg: An open-label antipsychotic switch study in outpatients with stable schizophrenia

BACKGROUND

Lumateperone is a mechanistically novel agent FDA-approved for the treatment of schizophrenia. Efficacy and favorable tolerability of lumateperone were demonstrated in 2 short-term placebo-controlled studies in patients with schizophrenia. This open-label study investigated the short-term safety/tolerability of lumateperone in outpatients with stable schizophrenia switched from previous antipsychotic treatment.

METHODS

Adult outpatients with stable schizophrenia were switched from previous antipsychotics to lumateperone 42 mg once daily for six weeks, then patients were switched back to previous or another approved antipsychotic for 2 weeks. The primary objective assessed adverse events (AE), vital signs, laboratory tests, and extrapyramidal symptoms (EPS). Schizophrenia symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Among 301 patients switched to lumateperone (study completion=71.2%), treatment-emergent AEs (TEAEs) occurred in 137 patients (45.5%), with 92 (30.6%) experiencing a drug-related TEAE. The most common drug-related TEAEs were somnolence (6.6%), headache (5.3%), and dry mouth (5.3%). Most TEAEs were mild or moderate in severity. EPS-related TEAEs were rare (1.0%). There were significant decreases from previous antipsychotics baseline in total cholesterol (P<.01), low-density lipoprotein cholesterol (P<.05), body weight (P<.01), and prolactin (P<.01); most of these parameters worsened within 2 weeks of resuming other antipsychotic treatment. PANSS Total scores remained stable relative to previous antipsychotics baseline during lumateperone treatment.

CONCLUSIONS

In outpatients with stable schizophrenia, lumateperone was well tolerated with low risk of cardiometabolic and EPS adverse effects and stably maintained or improved schizophrenia symptoms. These data further support the safety, tolerability, and effectiveness of lumateperone in patients with schizophrenia.

Lumateperone: First Approval

Lumateperone (Caplyta^®) is a novel, orally available agent developed by Intra-Cellular Therapies (under a license from Bristol-Myers Squibb) for the treatment of schizophrenia and other neuropsychiatric and neurological disorders. Lumateperone is a first-in-class selective and simultaneous modulator of serotonin, dopamine and glutamate. In December 2019, lumateperone received its first global approval in the USA for the treatment of schizophrenia in adults. The drug is also under clinical development for bipolar depression, behavioural disorders associated with dementia and Alzheimer's disease, sleep maintenance insomnia and major depressive disorders. This article summarizes the milestones in the development of lumateperone leading to this first approval for the treatment of schizophrenia.

Ruthenium-Catalyzed Electrochemical Synthesis of Indolines through Dehydrogenative [3 + 2] Annulation with H2 Evolution

A dehydrogenative [3 + 2] annulation reaction of aniline derivatives and alkenes has been developed via the ruthenium-electron catalytic systems for the synthesis of versatile indolines. Electricity is used as a sustainable oxidant to regenerate the active Ru(II) catalyst and promote H₂ evolution. This protocol is ecofriendly and easy to handle as it uses a simple undivided cell in mild conditions without the employment of metal oxidants.

Lumateperone for the Treatment of Schizophrenia

Introduction

Schizophrenia is a severe psychotic disorder that is diagnosed by the presence of hallucinations or delusions along with disorganized speech, disorganized thought, or negative symptoms that are present for at least six months. Roughly 1 in 10,000 people a year are diagnosed with this psychiatric disorder. It is a chronic disorder requiring a lifetime of treatment of which antipsychotics have been the mainstay of this treatment. First-generation antipsychotics have dystonia, parkinsonism, and development of Tardive Dyskinesia as major side effects, and they are also nonspecific in terms of their actions. Second Generation antipsychotics target more specific dopamine and sometimes serotonin receptors with less dystonic side effects; however, there are additional concerns for the development of metabolic syndrome. This review aims to look at new medication on the market, lumateperone, for the treatment of Schizophrenia.

Recent studies

In one four week study with 60mg and 120mg of Lumateperone compared, 4mg of Risperdal, and a placebo found that Lumateperone significantly decreased the total Positive and Negative Syndrome Scale (PANSS) from baseline. Safety analysis of this study also found that Lumateperone was not associated with EPS or significant weight gain. Another study found that 42mg of Lumateperone significantly decreased PANSS score over placebo and 28mg of Lumateperone with associated TEAEs of somnolence, sedation, fatigue, and constipation. In an open-label safety, patients were switched from their current antipsychotic to Lumateperone and then switched back to their previous treatment after six weeks. PATIENTS were found to have statistically significant improvements in metabolic parameters, weight, and endocrine parameters, which were all lost when they were switched back to their previous treatment and their schizophrenic symptoms at pre-trial levels or improved them while on Lumateperone. In a continuation of the previous study over 12 months, 4 TEAEs occurred in 5% or more of the participants: diarrhea, dry mouth, weight decrease, and headache. Prolactin, metabolic labs, BMI, and weight all decreased as compared to the standard of care. Pooled studies revealed EPS related TEAEs were less frequent in patients receiving 42 mg lumateperone over Risperdal. Another pooled study looked at the safety profile; they found patients treated with lumateperone, two TEAEs occurred at twice the placebo rate and at a rate of 5% or more: dry mouth (5% vs. 2.2%) and sedation (24.1% vs. 10.0%) though TEAE discontinuation rates were lower than with Risperdal.

Summary

Taken together, data from these trials suggest that lumateperone can effectively treat positive symptoms, negative symptoms, and cognitive dysfunction in schizophrenia. Lumateperone entrance to the market introduces an innovative way to treat schizophrenia featuring both a novel mechanism of action and a markedly reduced side effect profile. Further research is needed to determine the efficacy of Lumateperone in treating bipolar disorder in addition to schizophrenia.

Tailor-made amino acid-derived pharmaceuticals approved by the FDA in 2019

Amino acids (AAs) are among a handful of paramount classes of compounds innately involved in the origin and evolution of all known life-forms. Along with basic scientific explorations, the major goal of medicinal chemistry research in the area of tailor-made AAs is the development of more selective and potent pharmaceuticals. The growing acceptance of peptides and peptidomimetics as drugs clearly indicates that AA-based molecules become the most successful structural motif in the modern drug design. In fact, among 24 small-molecule drugs approved by FDA in 2019, 13 of them contain a residue of AA or di-amines or amino-alcohols, which are commonly considered to be derived from the parent AAs. In the present review article, we profile 13 new tailor-made AA-derived pharmaceuticals introduced to the market in 2019. Where it is possible, we will discuss the development form drug-candidates, total synthesis, with emphasis on the core-AA, therapeutic area, and the mode of biological activity.

Up-to-date expert opinion on the safety of recently developed antipsychotics

Introduction There are several new and emerging antipsychotic medication strategies recently marketed or under clinical development for the treatment of several mental disorders. There is the need to provide an up-to-date overview on the safety of this new generation of antipsychotic medications, which includes also the third-generation antipsychotics (TGA). Areas covered The authors aimed at providing a synthesis of the most current evidence about the safety profile of the recently developed and/or marketed antipsychotics. Qualitative synthesis followed an electronic search made inquiring of the following databases: MEDLINE, Embase, PsycINFO, and the Cochrane Library from inception until March 2020, combining free terms and MESH headings for the topics of TGA and recently developed and/or marketed antipsychotics as following: ((safety OR adverse events OR side effects) AND ((brexpiprazole OR cariprazine OR inhaled loxapine OR lumateperone (ITI-007) OR lurasidone OR pimavanserin OR roluperidone (MIN-101) OR transdermal patch asenapine)). Expert opinion Overall, newer antipsychotics display a good safety profile, with a well-demonstrated lower metabolic liability compared to second-generation antipsychotics. Furthermore, TGA appear to specifically target negative symptomatology and improving cognitive domains. Abbreviations Aps=Antipsychotic Drugs; AEs = Adverse Effects; EPS = Extrapyramidal Symptoms; NMS = Neuroleptic malignant syndrome; D = Dopamine; K_i = Inhibitory Constant; 5-HT = Serotonin; ECG = Electrocardiogram; H = Histamine; M = Muscarinic; BMI = Body Mass Index.

Pharmacological MRI responses of raclopride in rats: The relationship with D2 receptor occupancy and cataleptic behavior

Pharmacological magnetic resonance imaging (phMRI) allows the visualization of brain pharmacological effects of drugs using functional MRI (fMRI). phMRI can help us facilitate central nervous system (CNS) drug development. However, there have been few studies demonstrating the dose relationship of the fMRI response induced by CNS drugs to underlying target engagement or behavioral efficacy. To clarify these relationships, we examined receptor occupancy measurements using positron emission tomography (PET) (n = 3~5), fMRI (n = 5~8) and a cataleptic behavior (n = 6) with raclopride, a dopamine D2 receptor antagonist (8, 20, and 200 μg/kg) on Wistar rats. Dopamine D2 receptor occupancy was increased dose dependently by raclopride (41.8 ± 2.7%, 8 μg/kg; 64.9 ± 2.8%, 20 μg/kg; 83.1 ± 3.0%, 200 μg/kg). phMRI study revealed significant positive responses to raclopride at 200 μg/kg specifically in the striatum and nucleus accumbens, related to dopaminergic system. Slight fMRI responses were observed at 20 μg/kg in some areas corresponding to the striatum and nucleus accumbens. There were no noticeable fMRI responses at 8 μg/kg raclopride administration. Raclopride at 200 μg/kg significantly increased the cataleptic score, although, at 8 and 20 μg/kg, raclopride had no significant effects. These findings showed that raclopride-induced fMRI responses were observed at doses inducing cataleptic behavior and high D2 receptor occupancy, suggesting that phMRI can be useful for dose selection in clinical trial as an evaluation method of brain activity, which reflects behavioral responses induced by target engagements.

Efficacy and Safety of Lumateperone for Treatment of Schizophrenia: A Randomized Clinical Trial

Importance

Individuals living with schizophrenia are affected by cardiometabolic, endocrine, and motor adverse effects of current antipsychotic medications. Lumateperone is a serotonin, dopamine, and glutamate modulator with the potential to treat schizophrenia with few adverse effects.

Objective

To examine the efficacy and safety of lumateperone for the short-term treatment of schizophrenia.

Design, Setting, and Participants

This randomized, double-blind, placebo-controlled, phase 3 clinical trial was conducted from November 13, 2014, to July 20, 2015, with data analyses performed from August 13 to September 15, 2015. Patients with schizophrenia who were aged 18 to 60 years and were experiencing an acute exacerbation of psychosis were enrolled from 12 clinical sites in the United States.

Interventions

Patients were randomized 1:1:1 (150 patients in each arm) to receive lumateperone tosylate, 60 mg; lumateperone tosylate, 40 mg (equivalent to 42 or 28 mg, respectively, of the active moiety lumateperone); or placebo once daily for 4 weeks.

Main Outcomes and Measures

The prespecified primary efficacy end point was mean change from baseline to day 28 in the Positive and Negative Syndrome Scale (PANSS) total score vs placebo. The key secondary efficacy measure was the Clinical Global Impression-Severity of Illness (CGI-S) score. The PANSS subscale scores, social function, safety, and tolerability were also assessed.

Results

The study comprised 450 patients (mean [SD] age, 42.4 [10.2] years; 346 [77.1%] male; mean [SD] baseline PANSS score, 89.8 [10.3]; mean [SD] baseline CGI-S score, 4.8 [0.6]). In the prespecified modified intent-to-treat efficacy analysis (n = 435), 42 mg of lumateperone met the primary and key secondary efficacy objectives, demonstrating a statistically significant improvement vs placebo from baseline to day 28 on the PANSS total score (least-squares mean difference [LSMD], -4.2; 95% CI, -7.8 to -0.6; P = .02; effect size [ES], -0.3) and the CGI-S (LSMD, -0.3; 95% CI, -0.5 to -0.1; P = .003; ES, -0.4). For 28 mg of lumateperone, the LSMD from baseline to day 28 was -2.6 (95% CI, -6.2 to 1.1; P = .16; ES, -0.2) on the PANSS total score and -0.2 (95% CI, -0.5 to 0.0; P = .02; ES, -0.3) on the CGI-S. Both lumateperone doses were well tolerated without clinically significant treatment-emergent motor adverse effects or changes in cardiometabolic or endocrine factors vs placebo.

Conclusions and Relevance

Lumateperone demonstrated efficacy for improving the symptoms of schizophrenia and had a favorable safety profile.

Trial Registration

ClinicalTrials.gov identifier: NCT02282761.

Toward nanoscale localization of memory engrams in Drosophila

The Mushroom Body (MB) is the primary location of stored associative memories in the Drosophila brain. We discuss recent advances in understanding the MB's neuronal circuits made using advanced light microscopic methods and cell-type-specific genetic tools. We also review how the compartmentalized nature of the MB's organization allows this brain area to form and store memories with widely different dynamics.

An evaluation of lumateperone tosylate for the treatment of schizophrenia

Introduction: Schizophrenia, a devastating disorder with onset in adolescence or young adulthood, afflicts 1% of the population leading to severe social, educational, and occupational impairments. Lumateperone is a first-in-class investigational drug under development for the treatment of multiple neuropsychiatric and neurodegenerative disorders including schizophrenia. Its unique receptor affinity profile together with synergistic modulation of serotonergic, glutamatergic, and dopaminergic pathways imparts efficacy over a broad-spectrum of symptoms associated with schizophrenia.Areas covered: This narrative drug evaluation includes a review of lumateperone tosylate (lumateperone, ITI-007, ITI-722, Intra-Cellular Therapies, Inc.) for patients with schizophrenia. This review describes the receptor affinity profile, pharmacodynamics, pharmacokinetics, distribution, metabolism, and clinical trials that address how lumateperone could potentially emerge as an important therapeutic option for schizophrenia patients.Expert opinion: The unique pharmacological properties of lumateperone may provide the key to dramatically ameliorate the symptoms of schizophrenia as indicated by some clinical trials. Future clinical trials may be enhanced by the administration of more comprehensive long-term behavioral measures and utilization of molecular imaging to confirm the target engagement of the many possible sites of action. The results of ongoing and future studies will provide the evidence to determine if lumateperone will revolutionize the therapy of schizophrenia.

Nitric oxide acts as a cotransmitter in a subset of dopaminergic neurons to diversify memory dynamics

Animals employ diverse learning rules and synaptic plasticity dynamics to record temporal and statistical information about the world. However, the molecular mechanisms underlying this diversity are poorly understood. The anatomically defined compartments of the insect mushroom body function as parallel units of associative learning, with different learning rates, memory decay dynamics and flexibility (Aso and Rubin, 2016). Here, we show that nitric oxide (NO) acts as a neurotransmitter in a subset of dopaminergic neurons in Drosophila. NO's effects develop more slowly than those of dopamine and depend on soluble guanylate cyclase in postsynaptic Kenyon cells. NO acts antagonistically to dopamine; it shortens memory retention and facilitates the rapid updating of memories. The interplay of NO and dopamine enables memories stored in local domains along Kenyon cell axons to be specialized for predicting the value of odors based only on recent events. Our results provide key mechanistic insights into how diverse memory dynamics are established in parallel memory systems.