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.

Positive association between cerebral grey matter metabolism and dopamine D2/D3 receptor availability in healthy and schizophrenia subjects: An 18F-fluorodeoxyglucose and 18F-fallypride positron emission tomography study

Objectives: Overlapping decreases in extrastriatal dopamine D₂/D₃-receptor availability and glucose metabolism have been reported in subjects with schizophrenia. It remains unknown whether these findings are physiologically related or coincidental.Methods: To ascertain this, we used two consecutive ¹⁸F-fluorodeoxyglucose and ¹⁸F-fallypride positron emission tomography scans in 19 healthy and 25 unmedicated schizophrenia subjects. Matrices of correlations between ¹⁸F-fluorodeoxyglucose uptake and ¹⁸F-fallypride binding in voxels at the same xyz location and AFNI-generated regions of interest were evaluated in both diagnostic groups.Results:¹⁸F-fluorodeoxyglucose uptake and ¹⁸F-fallypride binding potential were predominantly positively correlated across the striatal and extrastriatal grey matter in both healthy and schizophrenia subjects. In comparison to healthy subjects, significantly weaker correlations in subjects with schizophrenia were confirmed in the right cingulate gyrus and thalamus, including the mediodorsal, lateral dorsal, anterior, and midline nuclei. Schizophrenia subjects showed decreased D₂/D₃-receptor availability in the hypothalamus, mamillary bodies, thalamus and several thalamic nuclei, and increased glucose uptake in three lobules of the cerebellar vermis.Conclusions: Dopaminergic system may be involved in modulation of grey matter metabolism and neurometabolic coupling in both healthy human brain and psychopathology. Hyperdopaminergic state in untreated schizophrenia may at least partly account for the corresponding decreases in grey matter metabolism.

Development of Neuroimaging-Based Biomarkers in Psychiatry

This chapter presents an overview of accumulating neuroimaging data with emphasis on translational potential. The subject will be described in the context of three disease states, i.e., schizophrenia, bipolar disorder, and major depressive disorder, and for three clinical goals, i.e., disease risk assessment, subtyping, and treatment decision.

D2/D3 dopamine receptor binding with [F-18]fallypride correlates of executive function in medication-naïve patients with schizophrenia

Converging evidence indicates that the prefrontal cortex is critically involved in executive control and that executive dysfunction is implicated in schizophrenia. Reduced dopamine D2/D3 receptor binding potential has been reported in schizophrenia, and the correlations with neuropsychological test scores have been positive and negative for different tasks. The aim of this study was to examine the relation between dopamine D2/D3 receptor levels with frontal and temporal neurocognitive performance in schizophrenia. Resting-state ¹⁸F-fallypride positron emission tomography was performed on 20 medication-naïve and 5 previously medicated for brief earlier periods patients with schizophrenia and 19 age- and sex-matched healthy volunteers. Striatal and extra-striatal dopamine D2/D3 receptor levels were quantified as binding potential using fallypride imaging. Magnetic resonance images in standard Talairach position and segmented into gray and white matter were co-registered to the fallypride images, and the AFNI stereotaxic atlas was applied. Two neuropsychological tasks known to activate frontal and temporal lobe function were chosen, specifically the Wisconsin Card Sorting Test (WCST) and the California Verbal Learning Test (CVLT). Images of the correlation coefficient between fallypride binding and WCST and CVLT performance showed a negative correlation in contrast to positive correlations in healthy volunteers. The results of this study demonstrate that lower fallypride binding potential in patients with schizophrenia may be associated with better performance. Our findings are consistent with previous studies that failed to find cognitive improvements with typical dopamine-blocking medications.

The frontal cortex as a network hub controlling mood and cognition: Probing its neurochemical substrates for improved therapy of psychiatric and neurological disorders

The highly-interconnected and neurochemically-rich frontal cortex plays a crucial role in the regulation of mood and cognition, domains disrupted in depression and other central nervous system disorders, and it is an important site of action for their therapeutic control. For improving our understanding of the function and dysfunction of the frontal cortex, and for identifying improved treatments, quantification of extracellular pools of neuromodulators by microdialysis in freely-moving rodents has proven indispensable. This approach has revealed a complex mesh of autoreceptor and heteroceptor interactions amongst monoaminergic pathways, and led from selective 5-HT reuptake inhibitors to novel classes of multi-target drugs for treating depression like the mixed α₂-adrenoceptor/5-HT reuptake inhibitor, S35966, and the clinically-launched vortioxetine and vilazodone. Moreover, integration of non-monoaminergic actions resulted in the discovery and development of the innovative melatonin receptor agonist/5-HT_2C receptor antagonist, Agomelatine. Melatonin levels, like those of corticosterone and the "social hormone", oxytocin, can now be quantified by microdialysis over the full 24 h daily cycle. Further, the introduction of procedures for measuring extracellular histamine and acetylcholine has provided insights into strategies for improving cognition by, for example, blockade of 5-HT₆ and/or dopamine D₃ receptors. The challenge of concurrently determining extracellular levels of GABA, glutamate, d-serine, glycine, kynurenate and other amino acids, and of clarifying their interactions with monoamines, has also been resolved. This has proven important for characterizing the actions of glycine reuptake inhibitors that indirectly augment transmission at N-methyl-d-aspartate receptors, and of "glutamatergic antidepressants" like ketamine, mGluR5 antagonists and positive modulators of AMPA receptors (including S47445). Most recently, quantification of the neurotoxic proteins Aβ42 and Tau has extended microdialysis studies to the pathogenesis of neurodegenerative disorders, and another frontier currently being broached is microRNAs. The present article discusses the above themes, focusses on recent advances, highlights opportunities for clinical "translation", and suggests avenues for further progress.

A validated LC–MS/MS method for neurotransmitter metabolite analysis in human cerebrospinal fluid using benzoyl chloride derivatization

Background: Human cerebrospinal fluid (CSF) is often acquired in Phase I clinical trials to assess the CNS penetration of new pharmacological agents and to search for biomarkers associated with PD effects. Robust methods for neurotransmitter metabolites in CSF have proven elusive, in part due to inadequate reversed phase LC retention. Results: Benzoyl chloride derivatization was used to promote retention for LC–MS/MS for a panel of neurotransmitter metabolites while delivering a concise method for sample preparation. Conclusion: A validated assay in human CSF was obtained for 3,4-dihydroxyphenylacetic acid, homovanillic acid, 3,4-dihydroxyphenylglycol and 5-hydroxyindoleacetic acid. This method is differentiated from other LC–MS/MS methods by delivering results in line with full regulatory expectations.

Treatment of early onset schizophrenia: recent trends, challenges and future considerations

Early onset schizophrenia (onset before adulthood) is a rare, severe, and chronic form of schizophrenia. The clinical presentation of schizophrenia at this unusually early age of onset has been associated with premorbid developmental abnormalities, poor response to neuroleptic treatment, greater admission rates, and poor prognosis. This is a brief, condensed review of current treatment strategies for the early onset population highlighting the need for novel treatment strategies for these generally treatment-refractory cases. Based on the current literature, second-generation antipsychotics remain the mainstay of treatment, although current medications provide suboptimal response at best. Based on the adult literature, combining antipsychotic treatment with psychotherapeutic intervention may be a more comprehensive treatment strategy. Indeed, early detection, identification of relevant biomarkers, coupled with advancing knowledge of the neurochemical and neuroanatomic pathways may help design informed and novel treatment strategies.

The application of selective reaction monitoring confirms dysregulation of glycolysis in a preclinical model of schizophrenia

BACKGROUND

Establishing preclinical models is essential for novel drug discovery in schizophrenia. Most existing models are characterized by abnormalities in behavioral readouts, which are informative, but do not necessarily translate to the symptoms of the human disease. Therefore, there is a necessity of characterizing the preclinical models from a molecular point of view. Selective reaction monitoring (SRM) has already shown promise in preclinical and clinical studies for multiplex measurement of diagnostic, prognostic and treatment-related biomarkers.

METHODS

We have established an SRM assay for multiplex analysis of 7 enzymes of the glycolysis pathway which is already known to be affected in human schizophrenia and in the widely-used acute PCP rat model of schizophrenia. The selected enzymes were hexokinase 1 (Hk1), aldolase C (Aldoc), triosephosphate isomerase (Tpi1), glyceraldehyde-3-phosphate dehydrogenase (Gapdh), phosphoglycerate mutase 1 (Pgam1), phosphoglycerate kinase 1 (Pgk1) and enolase 2 (Eno2). The levels of these enzymes were analyzed using SRM in frontal cortex from brain tissue of PCP treated rats.

RESULTS

Univariate analyses showed statistically significant altered levels of Tpi1 and alteration of Hk1, Aldoc, Pgam1 and Gapdh with borderline significance in PCP rats compared to controls. Most interestingly, multivariate analysis which considered the levels of all 7 enzymes simultaneously resulted in generation of a bi-dimensional chart that can distinguish the PCP rats from the controls.

CONCLUSIONS

This study not only supports PCP treated rats as a useful preclinical model of schizophrenia, but it also establishes that SRM mass spectrometry could be used in the development of multiplex classification tools for complex psychiatric disorders such as schizophrenia.

The challenges and promise of neuroimaging in psychiatry

Neuroimaging is central to the quest for a biological foundation of psychiatric diagnosis but so far has not yielded clinically relevant biomarkers for mental disorders. This review addresses potential reasons for this limitation and discusses refinements of paradigms and analytic techniques that may yield improved diagnostic and prognostic accuracy. Neuroimaging can also be used to probe genetically defined biological pathways underlying mental disorders, for example through the genetic imaging of variants discovered in genome-wide association studies. These approaches may ultimately reveal mechanisms through which genes contribute to psychiatric symptoms and how pharmacological and psychological interventions exert their effects.

Can genetics inform the management of cognitive deficits in schizophrenia?

There is no doubt that schizophrenia has a significant genetic component and a number of candidate genes have been identified for this debilitating disorder. Of note, several of these are implicated in cognition. Cognitive deficits constitute core symptoms of schizophrenia, and while current antipsychotic treatment strategies aim to help psychosis-related symptomatology, the cognitive symptom domain is largely inadequately treated. A number of other pharmacological approaches (e.g. using drugs that target specific neurotransmitter systems) have also been attempted for the amelioration of cognitive deficits in this population; however, these too have had limited success so far. Psychological interventions appear promising, though there has been speculation regarding whether or not these produce long-term functional improvements. Pharmacogenetic studies of the cognitive effects of currently available antipsychotics, although in relatively early stages, suggest that the treatment of cognitive deficits in schizophrenia may be advanced by focusing on genetic variants associated with specific cognitive dysfunctions in the general population and using this to match the most relevant pharmacological and/or psychological interventions with the genetic and cognitive profiles of the target population. Such a strategy would encourage bottom-up advances in drug development and provide a platform for individualised treatment of cognitive deficits in schizophrenia.

Cognitive dysfunction in psychiatric disorders: characteristics, causes and the quest for improved therapy

Studies of psychiatric disorders have traditionally focused on emotional symptoms such as depression, anxiety and hallucinations. However, poorly controlled cognitive deficits are equally prominent and severely compromise quality of life, including social and professional integration. Consequently, intensive efforts are being made to characterize the cellular and cerebral circuits underpinning cognitive function, define the nature and causes of cognitive impairment in psychiatric disorders and identify more effective treatments. Successful development will depend on rigorous validation in animal models as well as in patients, including measures of real-world cognitive functioning. This article critically discusses these issues, highlighting the challenges and opportunities for improving cognition in individuals suffering from psychiatric disorders.

Biomarkers in development of psychotropic drugs

Biomarkers have been receiving increasing attention, especially in the field of psychiatry. In contrast to the availability of potent therapeutic tools including pharmacotherapy, psychotherapy, and biological therapies, unmet needs remain in terms of onset of action, stability of response, and further improvement of the clinical course. Biomarkers are objectively measured characteristics which serve as indicators of the causes of illnesses, their clinical course, and modification by treatment. There exist a variety of markers: laboratory markers which comprise the determination of genetic and epigenetic markers, neurotransmitters, hormones, cytokines, neuropeptides, enzymes, and others as single measures; electrophysiological markers which usually comprise electroencephalography (EEG) measures, and in particular sleep EEG and evoked potentials, magnetic encephalography, electrocardiogram, facial electromyography, skin conductance, and others; brain imaging techniques such as cranial computed tomography, magnetic resonance imaging, functional MRl, magnetic resonance spectroscopy, positron emission tomography, and single photon emission computed tomography; and behavioral approaches such as cue exposure and challenge tests which can be used to induce especially emotional processes in anxiety and depression. Examples for each of these domains are provided in this review. With a view to developing more individually tailored therapeutic strategies, the characterization of patients and the courses of different types of treatment will become even more important in the future.

Neurological imaging: statistics behind the pictures

Neurological imaging represents a powerful paradigm for investigation of brain structure, physiology and function across different scales. The diverse phenotypes and significant normal and pathological brain variability demand reliable and efficient statistical methodologies to model, analyze and interpret raw neurological images and derived geometric information from these images. The validity, reproducibility and power of any statistical brain map require appropriate inference on large cohorts, significant community validation, and multidisciplinary collaborations between physicians, engineers and statisticians.

Neurobiology and phenotypic expression in early onset schizophrenia

AIM

Early-onset schizophrenia (onset before adulthood) is a rare and severe form of the disorder that shows phenotypic and neurobiological continuity with adult-onset schizophrenia. Here, we provide a synthesis of keynote findings in this enriched population to understand better the neurobiology and pathophysiology of early-onset schizophrenia.

METHODS

A synthetic and integrative approach is applied to review studies stemming from epidemiology, phenomenology, cognition, genetics and neuroimaging data. We provide conclusions and future directions of research on early-onset schizophrenia.

RESULTS

Childhood and adolescent-onset schizophrenia is associated with severe clinical course, greater rates of premorbid abnormalities, poor psychosocial functioning and increased severity of brain abnormalities. Early-onset cases show similar neurobiological correlates and phenotypic deficits to adult-onset schizophrenia, but show worse long-term psychopathological outcome. Emerging technological advances have provided important insights into the genomic architecture of early-onset schizophrenia, suggesting that some genetic variations may occur more frequently and at a higher rate in young-onset than adult-onset cases.

CONCLUSIONS

Clinical, cognitive, genetic and imaging data suggest increased severity in early-onset schizophrenia. Studying younger-onset cases can provide useful insights into the neurobiological mechanisms of schizophrenia and the complexity of gene-environment interactions leading to the emergence of this debilitating disorder.