The effect of brexpiprazole (OPC-34712) and aripiprazole in adult patients with acute schizophrenia: results from a randomized, exploratory study

Brexpiprazole in patients with schizophrenia with or without substance use disorder: an observational study

Background

Partial dopamine D2 receptor agonists are used for psychotic symptoms in adults with schizophrenia spectrum disorders. Recently, interest surged for partial dopamine D2 receptor agonists in substance use disorders (SUDs). Since it is believed that SUDs decrease the efficacy of pharmacotherapy of underlying psychiatric disorders, we tested the efficacy of the partial D2 agonist brexpiprazole in patients with schizophrenia who were either comorbid with a SUD (SUD group) or not comorbid (non-SUD) to assess treatment response and the effect of brexpiprazole on substance craving in SUD.

Methods

We included patients with DSM-5/DSM-5-TR schizophrenia (using SCID-5-CV) aged 18-66 years with either comorbid SUD or non-SUD to treat with brexpiprazole 4 mg/day for 6 months during February-October 2022. Patients were assessed with the Clinical Global Impressions-Severity (CGI-S) scale, the 24-item Brief Psychiatric Rating Scale (BPRS), and the Positive And Negative Syndrome Scale (PANSS) at baseline, weekly for the first 2 months and monthly for the next four. Furthermore, we assessed substance craving in SUD with a visual analog scale for craving (VAScrav) at the same timepoints.

Results

The total sample was 86 (85 analysable) 18- to 64-year-old (mean 39.32 ± 14.09) patients with schizophrenia [51 men (59.3%) and 35 women (40.7%)], of whom 48 SUD (55.8%) (37 men and 11 women) and 38 non-SUD (44.2%) (14 men and 24 women). No serious or persistent adverse events developed over the study period, but one patient dropped out for subjective akathisia. Results indicated the main effects of time with improvements over the course of the study for CGI-S, BPRS, and PANSS in both SUD and non-SUD groups and the entire sample, and for VAScrav in SUD. Brexpiprazole was associated with similar significant improvements in both groups at the 6 month endpoint compared to baseline.

Conclusion

Treatment with brexpiprazole for 6 months improved psychotic symptoms in patients with schizophrenia, independently from whether they belonged to the SUD or the non-SUD group; hence, SUD comorbidity did not confer treatment resistance to brexpiprazole. Furthermore, in the SUD group, we observed reduced substance craving.

Brexpiprazole—Pharmacologic Properties and Use in Schizophrenia and Mood Disorders

In 2002, the first III generation antipsychotic drug was registered—aripiprazole. Its partial dopaminergic agonism underlies its unique mechanism of action and the potentially beneficial influence on the positive, negative, or cognitive symptoms. Due to its relatively high intrinsic activity, the drug could often cause agitation, anxiety, or akathisia. For this reason, efforts were made to develop a drug which would retain the positive favorable actions of aripiprazole but present a more advantageous clinical profile. This turned out to be brexpiprazole, which was registered in 2015. Its pharmacodynamic and pharmacokinetic profile (similarly to the other most recent antipsychotics, i.e., lurasidone or cariprazine) shows promise of increasing the effectiveness of schizophrenia treatment in the dimensions in which the previous antipsychotics were not sufficiently effective, including negative, depressive, or cognitive symptoms. Like other new antipsychotics, it can also be useful in the treatment of mood disorders, for instance drug-resistant depression. Previous reviews focused on the use of brexpiprazole in specific diagnostic groups. The aim of this article is to provide the readers with an overview of data on the mechanism of action, clinical effectiveness in all studied diagnostic groups, as well as potential drug–food interactions, and the safety of brexpiprazole.

Risk of Drug-induced Movement Disorders with Newer Antipsychotic Agents

Background:

The last decade has seen development of numerous novel antipsychotic drugs with unique mechanisms including long-acting formulations for clinical use. A comparative assessment of these new drugs with each other and previous antipsychotics have not been performed with regards to risk for drug-induced movement disorders (DIMD).

Methods:

Medline was searched from January 2010 to February 2022 for primary research articles and review articles in English using the search terms “extrapyramidal” and “tardive” with individual drug names of novel antipsychotics.

Results:

We identified articles describing the risk of DIMD with 6 novel antipsychotics, 4 novel formulations, and 3 experimental antipsychotics. Both short- and long-term data generally showed comparable to lower risk of DIMD with novel antipsychotics and recent long-acting formulations compared to previously marketed antipsychotics.

Discussion:

Several novel antipsychotics, particularly lumateperone and pimavanserin, show promise in being able to treat psychosis while reducing the risk of DIMD. Long-acting paliperidone may reduce risk of DIMD while other long-acting injectable formulations of SGA have similar risk of DIMD compared to oral formulations. New drug targets for treating psychosis without dopamine blockade also show promise.

Polypharmacology: The science of multi-targeting molecules

Polypharmacology is a concept where a molecule can interact with two or more targets simultaneously. It offers many advantages as compared to the conventional single-targeting molecules. A multi-targeting drug is much more efficacious due to its cumulative efficacy at all of its individual targets making it much more effective in complex and multifactorial diseases like cancer, where multiple proteins and pathways are involved in the onset and development of the disease. For a molecule to be polypharmacologic in nature, it needs to possess promiscuity which is the ability to interact with multiple targets; and at the same time avoid binding to antitargets which would otherwise result in off-target adverse effects. There are certain structural features and physicochemical properties which when present would help researchers to predict if the designed molecule would possess promiscuity or not. Promiscuity can also be identified via advanced state-of-the-art computational methods. In this review, we also elaborate on the methods by which one can intentionally incorporate promiscuity in their molecules and make them polypharmacologic. The polypharmacology paradigm of "one drug-multiple targets" has numerous applications especially in drug repurposing where an already established drug is redeveloped for a new indication. Though designing a polypharmacological drug is much more difficult than designing a single-targeting drug, with the current technologies and information regarding different diseases and chemical functional groups, it is plausible for researchers to intentionally design a polypharmacological drug and unlock its advantages.

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.

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.

Efficacy and safety of antipsychotic treatments for schizophrenia: A systematic review and network meta-analysis of randomized trials in Japan

BACKGROUND

We examined the efficacy and safety of using antipsychotic medication for schizophrenia using only randomized trials of antipsychotic for schizophrenia conducted in Japan to avoid the biological and environmental heterogeneities caused by pooling data from various races and ethnicities.

METHODS

We searched for eligible studies on Embase, PubMed, and CENTRAL. Primary outcomes were improvement in Positive and Negative Syndrome Scale total score (PANSS-T) and all-cause discontinuation. Other outcomes were improvement in PANSS subscale scores, discontinuation due to adverse events or inefficacy, and the incidence of 16 adverse events.

RESULTS

We calculated mean difference or risk ratios and 95% credible intervals. We identified 34 RCTs (6798 patients; mean study duration, 9.0 ± 4.24 weeks; proportion of male patients, 53.7%; mean age, 43.3 years). Besides placebo, studies included aripiprazole, asenapine, blonanserin, blonanserin-patch, brexpiprazole, clocapramine (no PANSS data), clozapine (no PANSS data), haloperidol, lurasidone, mosapramine, olanzapine, paliperidone, perospirone, quetiapine, and risperidone. Efficacy and safety profiles differed for antipsychotics used with schizophrenia in Japanese patients. All active treatments other than haloperidol and quetiapine outperformed placebo to improve PANSS-T. Asenapine, olanzapine, paliperidone, and risperidone outperformed placebo for all-cause discontinuation. Asenapine, blonanserin, blonanserin-patch, haloperidol, lurasidone, mosapramine, olanzapine, paliperidone, and risperidone outperformed placebo to improve PANSS positive subscale scores. Aripiprazole, asenapine, blonanserin, blonanserin-patch, brexpiprazole, lurasidone, olanzapine, paliperidone, perospirone, and risperidone outperformed placebo to improve PANSS negative subscale scores. The confidence in evidence of most outcomes was low or very low.

CONCLUSION

Our results are similar to those of previous network meta-analysis involving various races and ethnicities.

Discovery research and development history of the dopamine D2 receptor partial agonists, aripiprazole and brexpiprazole

Otsuka Pharmaceutical Co., Ltd. successfully developed the first dopamine D₂ receptor partial agonist approved for schizophrenia, the antipsychotic aripiprazole (Abilify^®). The drug was approved for this indication in the United States in 2002 and has received approval in the United States, Europe, Japan, and many other countries for several indications including schizophrenia, acute mania, adjunctive treatment of major depressive disorder (MDD), irritability associated with autistic disorder, and Tourette's disorder. Otsuka next developed brexpiprazole (Rexulti^®), another D₂ receptor partial agonist, which was granted marketing approval in the United States in 2015 as adjunctive therapy in major depressive disorder and for the treatment of schizophrenia. In Japan, brexpiprazole also received approval as a treatment for schizophrenia in 2018. In this review, we describe Otsuka's research history and achievements over the preceding 40 years in the area of antipsychotic drug discovery for dopamine D₂ receptor partial agonists.

“Dopamine‐system stabilizer” activity of aripiprazole.

Dopamine Receptor Partial Agonists: Do They Differ in Their Clinical Efficacy?

Dopamine receptor partial agonists (DRPAs; aripiprazole, brexpiprazole, and cariprazine) constitute a novel class of antipsychotics. Although they share a similar mechanism of action, DRPAs differ in their pharmacodynamics, pharmacokinetics, drug interactions, or safety and tolerability. The antipsychotic efficacy of all three drugs was established in several placebo-controlled randomized trials (RCTs) in schizophrenia, both acute phase and relapse prevention. In addition, each of the DRPA agents has been tested in other psychiatric disorders, including bipolar disorder or major depression. However, a few studies have examined their comparative clinical efficacy. There are no head-to-head comparisons between aripiprazole, brexpiprazole, or cariprazine. In two acute schizophrenia RCTs of cariprazine and brexpiprazole, aripiprazole was used as an indirect comparator to control for study sensitivity. To assess potential differences in the efficacy of DRPAs, we reviewed data from controlled trials, systematic reviews, and meta-analyses. Our results showed that the acute antipsychotic effects of DRPAs, as measured by the number needed to treat, are comparable. The three agents were superior to placebo in acute treatment, and cariprazine was found to be effective in the reduction of primary negative symptoms of schizophrenia. In the therapy of bipolar disorder, aripiprazole and cariprazine showed antimanic efficacy, cariprazine was also effective in the management of bipolar depression, and aripiprazole was effective for relapse prevention. The addon administration of aripiprazole or brexpiprazole reduced symptoms of major depression. Aripiprazole can control acute agitation associated with psychosis or bipolar disorder; brexpiprazole showed the potential to manage agitation in dementia patients. Aripiprazole has also established evidence of efficacy in children and adolescents and other conditions: OCD, tic disorders, and autism spectrum disorder. Our review of published data suggests that in terms of clinical efficacy, DRPAs are a heterogeneous group, with each drug possessing its own therapeutic benefits.

Brexpiprazole for the Treatment of Schizophrenia in Adults: An Overview of Its Clinical Efficacy and Safety and a Psychiatrist's Perspective

While the prognosis of patients with schizophrenia has dramatically improved after the advent of chlorpromazine, the antipsychotics currently available are so numerous that it has become a challenge for psychiatrists to choose from among these drugs for each patient presenting for care. In addition, while numerous studies show that an effective antipsychotic should be continued indefinitely to prevent relapses or worsening, many patients appear to have difficulty remaining on any drug thus initiated. Brexpiprazole, a dopamine D₂ receptor partial agonist, appears to provide a unique profile that has much to offer in this light. Specifically, this novel drug is potentially better suited for long-term use, with decreased risk of extrapyramidal side effects, hyperprolactinemia, weight gain, psychosis, insomnia, akathisia, nausea/vomiting or restlessness, thus potentially facilitating patients' reintegration into society. Indeed, brexpiprazole has been shown in randomized, double-blind, placebo-controlled trials to have proven efficacy not only in improving the symptoms of schizophrenia but in preventing relapses. It is also suggested in both short- and long-term studies that brexpiprazole offers a favorable safety and tolerability profile. This review also includes a proposed treatment algorithm incorporating brexpiprazole, based on the clinical trial results available, as well as on the authors' clinical experience, where brexpiprazole may be best used as a drug of first choice for the treatment of schizophrenia. Thus, overall, brexpiprazole appears to play a more significant role in the treatment of schizophrenia than other antipsychotics.

Updating the Comparative Evidence on Second‐Generation Antipsychotic Use With Schizophrenia

Objective

The objective of this study was to conduct a systematic review of literature comparing second‐generation antipsychotics (SGAs) with each other and with first‐generation antipsychotics (FGAs) in treating schizophrenia.

Methods

MEDLINE, the Cochrane Library, and PsycINFO databases were searched through January 2020. Following standard methods, recent high‐quality systematic reviews of each drug comparison and subsequently published primary studies were included to update the meta‐analyses with any new data. Two reviewers independently conducted study selection, abstraction, and quality assessment.

Results

Two systematic reviews and 29 newer trials (total of 162 trials of SGAs, N=53,861; 116 trials of SGAs versus FGAs, N=119,558) were included. Most trials were of fair quality, industry‐funded, and included older SGAs and a few recently approved SGAs (asenapine, lurasidone, iloperidone, cariprazine, brexpiprazole and long‐acting injection [LAI] formulations of aripiprazole and paliperidone). Older SGAs had similar effects on function, quality of life, mortality, and adverse event incidence, although clozapine improved symptoms more than most other drugs and olanzapine and risperidone were superior to some other drugs. Olanzapine, risperidone, ziprasidone, and aripiprazole performed similarly on outcomes of benefit compared with haloperidol. Risperidone LAI and olanzapine resulted in fewer withdrawals due to adverse events, but risk of diabetes increased with olanzapine. Haloperidol had greater incidence of adverse events than did olanzapine and risperidone, but similar effects on other outcomes.

Conclusions

Most comparative evidence favored older SGAs, with clozapine, olanzapine, and risperidone superior on more outcomes than other SGAs. Older SGAs had similar benefits as haloperidol but with fewer adverse events.

Use of the second‐generation antipsychotics olanzapine, aripiprazole, risperidone, quetiapine, and ziprasidone resulted in similar function, quality of life, mortality, and overall incidence of adverse events.

Core illness symptoms improved more with olanzapine and risperidone than asenapine, quetiapine, or ziprasidone, and more with paliperidone than lurasidone or iloperidone.

Haloperidol showed similar benefits but more adverse events than did olanzapine or risperidone.

Effect of brexpiprazole on control of impulsivity in schizophrenia: A randomized functional magnetic resonance imaging study

Impulsivity in schizophrenia is a risk factor for suicide, drug abuse, and other risk-taking behaviors. This exploratory, multicenter, randomized, double-blind, functional magnetic resonance imaging (fMRI) study assessed the effects of brexpiprazole on brain regions that control impulsive behavior. Thirty-eight outpatients with stable schizophrenia and impulsivity symptoms were randomized to 6 weeks of brexpiprazole 2 or 4 mg/day. The prespecified outcome measure was blood oxygen-level dependent (BOLD) activation in the right ventrolateral prefrontal cortex (VLPFC) during performance of tasks associated with inhibition/control of impulsivity: the go/no-go task and stop-signal task. Secondary objectives evaluated the efficacy, safety and tolerability of brexpiprazole. Over 6 weeks, patients receiving brexpiprazole had no statistically significant change in right VLPFC BOLD activation during the go/no-go task, but showed a significant decrease in right VLPFC BOLD activation during the stop-signal task. Brexpiprazole was also associated with significantly improved stop-signal reaction time (SSRT). No worsening of psychiatric symptoms, functioning, or impulsivity occurred in these patients. No unexpected safety or tolerability concerns were identified. In conclusion, brexpiprazole treatment among patients with schizophrenia and impulsivity was associated with decreased right VLPFC activation and decreased SSRT, supportive of a benefit of brexpiprazole on inhibition-related brain activation and behavior. ClinicalTrials.gov identifier: NCT02194933.

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.

Brexpiprazole in the treatment of schizophrenia and agitation in Alzheimer's disease

Schizophrenia is a disabling psychiatric disorder marked by progressive loss of functionality in activities of daily living with each relapse. Antipsychotics, the mainstay of therapy for schizophrenia, treat hallucinations and delusions but may have intolerable side effects, including metabolic disturbances and extrapyramidal symptoms. Brexpiprazole, a second-generation antipsychotic with dopamine partial agonist properties, was approved by the US FDA in 2015 for the treatment of schizophrenia and adjunctive treatment of major depressive disorder and by the EU in 2018 for adults with schizophrenia. Additionally, brexpiprazole has recently been studied for the treatment of agitation in Alzheimer's dementia, an area of largely unmet need. Overall, well-tolerated brexpiprazole expands the armamentarium of treatment options available for these conditions.

Comparative Tolerability of Dopamine D2/3 Receptor Partial Agonists for Schizophrenia

Aripiprazole, brexpiprazole and cariprazine differ from all other second-generation antipsychotics due to partial agonism at the dopamine D2 and D3 receptors. In contrast to aripiprazole, brexpiprazole has lower intrinsic dopamine D2 activity and higher affinity for the serotonin 5-HT1A and 5-HT2A receptors, while cariprazine has the highest affinity for the dopamine D3 receptor, and the longest half-life. The main adverse effect of dopamine receptor partial agonists (DRPAs) is akathisia of low-to-moderate severity, which occurs in a small proportion of patients, usually in the first few weeks of treatment. While definitive conclusions concerning differences between the DRPAs require head-to-head comparison studies, on the available evidence, akathisia is probably least likely to occur with brexpiprazole and most likely with cariprazine; the risk of akathisia with aripiprazole lies in between. Weight-gain risk is low with aripiprazole and cariprazine, but moderate with brexpiprazole. Risk of sedation is low with DRPAs, as is risk of insomnia and nausea. Partial dopamine agonism leads to a low risk for hyperprolactinaemia (and probably a low risk of sexual dysfunction). Prolactin concentrations fall in some patients (particularly those with elevated levels prior to initiating the drugs). Rates of discontinuation due to adverse effects in pivotal studies were low, and on the whole, DRPAs are well tolerated. Aripiprazole has been implicated in pathological gambling and other impulse control behaviours, likely due to partial dopamine agonist activity (there have been no reports with brexpiprazole and cariprazine). The risks for diabetes and tardive dyskinesia with DRPAs are unknown, but are likely to be low. On the basis of tolerability, DRPAs should be considered as first-line treatment options, particularly in patients with early schizophrenia.

Aripiprazole vs. brexpiprazole for acute schizophrenia: a systematic review and network meta-analysis

RATIONALE

What is the difference between aripiprazole and brexpiprazole?

OBJECTIVES

This systematic review, network meta-analysis of randomized trials evaluated the efficacy and safety/tolerability of aripiprazole and brexpiprazole for treating acute schizophrenia.

METHODS

We searched Scopus, MEDLINE, and Cochrane Library from inception until May 22, 2019. The response rate was set as the primary outcome. Other outcomes were discontinuation rate and incidence of individual adverse events. The risk ratio (RR) and 95% credible interval (95%CrI) were calculated.

RESULTS

Fourteen studies were identified (n = 3925). Response rates of both aripiprazole and brexpiprazole were superior to that of the placebo (RR [95%CrI]: aripiprazole = 0.84 [0.78, 0.92], brexpiprazole = 0.84 [0.77, 0.92]). Aripiprazole and brexpiprazole were associated with a lower incidence of all-cause discontinuation (0.80 [0.71, 0.89], 0.83 [0.72, 0.95]), adverse events (0.67 [0.47, 0.97], 0.64 [0.46, 0.94]), and inefficacy (0.56 [0.40, 0.77], 0.68 [0.48, 0.99]) compared with the placebo. Although brexpiprazole was associated with a lower incidence of schizophrenia as an adverse event compared with the placebo (0.57 [0.37, 0.85]), aripiprazole and brexpiprazole were associated with a higher incidence of weight gain compared with the placebo (2.12 [1.28, 3.68], 2.14 [1.35, 3.42]). No significant differences were found in other individual adverse events, such as somnolence, akathisia, extrapyramidal symptoms, and dizziness between aripiprazole or brexpiprazole and placebo. Any outcome between aripiprazole and brexpiprazole were not different.

CONCLUSIONS

Differences in short-term efficacy and safety for acute schizophrenia were not apparent between aripiprazole and brexpiprazole. Future studies are warranted to evaluate whether there are differences in the long-term outcome between treatments.

Efficacy and safety of brexpiprazole in acute management of psychiatric disorders: a meta-analysis of randomized controlled trials

Brexpiprazole is a new atypical antipsychotic for schizophrenia management and as adjunct in major depressive disorder (MDD). We searched randomized controlled trials (RCT) to review brexpiprazole efficacy and tolerability in acute management of schizophrenia and MDD using PubMed, EUDRACT, ClinicalTrials.gov and Cochrane Central Register of Controlled Trials. A meta-analysis was conducted using the identified 14 RCT to assess its efficacy using positive and negative syndrome scale (PANSS), clinical global impressions - severity of illness (CGI-S), personal and social performance scale (PSP), Montgomery-Åsberg depression rating scale (MADRS), Sheehan disability scale (SDS) and Hamilton depression rating scale (HDRS17). The mean difference comparing brexpiprazole and placebo were PANSS -4.48, CGI-S -0.23 and PSP 3.24 favoring brexpiprazole. Compared to aripiprazole and quetiapine, brexpiprazole showed similar efficacy. In MDD, brexpiprazole showed efficacy compared to placebo demonstrated by MADRS -1.25, SDS -0.37 and HDRS17 -1.28. Brexpiprazole was associated with side effects including akathisia risk ratio (RR) = 1.72; weight increase RR = 2.74 and somnolence RR = 1.87. Compared to 4 mg, brexpiprazole 2 mg was associated with less risk of akathisia and somnolence. Brexpiprazole demonstrated significant improvements in schizophrenia and MDD and is well-tolerated; however, associated with akathisia and somnolence. These findings will guide psychiatrists and pharmacists in their clinical role for supporting psychiatric patients care.

Health Care Cost in Patients With Schizophrenia Treated With Brexpiprazole Versus Other Oral Atypical Antipsychotic Therapy

PURPOSE

Brexpiprazole is an oral atypical antipsychotic (OAA) for the treatment of schizophrenia (SCZ). This study compared all-cause and psychiatric inpatient hospitalization and medical costs in adult patients with SCZ newly treated with brexpiprazole versus other US Food and Drug Administration-approved OAAs in a real-world setting.

METHODS

This retrospective cohort study analyzed data from: (1) the IBM MarketScan Commercial and Medicare Supplemental databases, and the MarketScan Multi-State Medicaid database; and (2) the de-identified Optum Clinformatics Datamart. Adult patients were identified if they had SCZ and initiated either brexpiprazole or another OAA during the study identification period (July 1, 2015, to September 30, 2016, for MarketScan Commercial and Medicare Supplemental and for Optum; July 1, 2015, to June 30, 2016, for MarketScan Multi-State Medicaid) and had ≥12 months of continuous enrollment before (baseline) and after (follow-up) the first treatment date. Linear regression analyses were performed to test associations between treatment groups (brexpiprazole vs another OAA) and costs (total and medical); negative binomial regression models were used to estimate number of hospitalizations per year, adjusting for baseline characteristics and medication adherence to index treatment during the 12-month follow-up.

FINDINGS

The final study sample consisted of 6254 patients with SCZ: 176 initiated brexpiprazole; 391, ziprasidone; 453, paliperidone; 523, lurasidone; 786, aripiprazole; 1234, quetiapine; 1264, olanzapine; and 1427, risperidone. Controlling for baseline characteristics and medication adherence, the adjusted number of hospitalizations (both all-cause and psychiatric), all-cause total costs, and all-cause medical costs did not differ across groups. Brexpiprazole users had the lowest mean psychiatric costs among all OAA users ($12,013; 95% bootstrap CI, 7488-16,538). Compared with brexpiprazole users, paliperidone (incidence rate ratio [95% CI], 1.52 [1.05-2.19]; P = 0.027) and quetiapine (incidence rate ratio [95% CI], 1.47 [1.04-2.07]; P = 0.029) users had more psychiatric hospitalizations per year. Paliperidone had higher psychiatric costs than brexpiprazole (total, $32,066 [95% bootstrap CI, 28,779-35,353] vs $23,851 [18,907-28,795]; medical, $19,343 [16,294-22,392] vs $12,013 [7488-16,538]). Psychiatric medical costs were also $6744 higher in olanzapine users (95% bootstrap CI, 1694-11,795; P = 0.009) than in brexpiprazole users.

IMPLICATIONS

Patients with SCZ treated with brexpiprazole had fewer psychiatric hospitalizations and lower psychiatric costs than those treated with paliperidone. Differences in the number of all-cause hospitalizations and medical costs among treatments were not statistically significant. Although treatment decisions are driven by a number of factors (eg, clinical circumstances and drug costs), choice of OAA may affect health care costs.

Dopamine-receptor blocking agent-associated akathisia: a summary of current understanding and proposal for a rational approach to treatment

Dopamine-receptor blocking agent-associated akathisia (DRBA-A) is an adverse effect that can significantly limit the use of these important medications for the treatment of a variety of psychiatric diseases, yet there is no unifying theory regarding its pathophysiology. This knowledge gap limits clinicians' ability to effectively manage DRBA-A and mitigate negative outcomes in an already vulnerable patient population. Based on a review of the current literature on the subject, it is hypothesized that dopaminergic and noradrenergic signaling is perturbed in DRBA-A. Accordingly, it is proposed that the optimal agent to manage this extrapyramidal symptom should increase dopamine signaling in the affected areas of the brain and counteract compensatory noradrenergic signaling via antagonism of adrenergic or serotonergic receptors.

Brexpiprazole, a Serotonin-Dopamine Activity Modulator, Can Sensitize Glioma Stem Cells to Osimertinib, a Third-Generation EGFR-TKI, via Survivin Reduction

Glioblastoma is a primary brain tumor associated with a poor prognosis due to its high chemoresistance capacity. Cancer stem cells (CSCs) are one of the mechanisms of chemoresistance. Although therapy targeting CSCs is promising, strategies targeting CSCs remain unsuccessful. Abnormal activation of epidermal growth factor receptors (EGFRs) due to amplification, mutation, or both of the EGFR gene is common in glioblastomas. However, glioblastomas are resistant to EGFR tyrosine kinase inhibitors (EGFR-TKIs), and overcoming resistance is essential. Brexpiprazole is a new, safe serotonin-dopamine activity modulator used for schizophrenia and depression that was recently reported to have anti-CSC activity and function as a chemosensitizer. Here, we examined its chemosensitization effects on osimertinib, a third-generation EGFR-TKI with an excellent safety profile, in glioma stem cells (GSCs), which are CSCs of glioblastoma. Brexpiprazole treatment sensitized GSCs to osimertinib and reduced the expression of survivin, an antiapoptotic factor, and the pharmacological and genetic inhibition of survivin mimicked the effects of brexpiprazole. Moreover, co-treatment of brexpiprazole and osimertinib suppressed tumor growth more efficiently than either drug alone without notable toxicity in vivo. This suggests that the combination of brexpiprazole and osimertinib is a potential therapeutic strategy for glioblastoma by chemosensitizing GSCs through the downregulation of survivin expression.

Medication-Induced Akathisia with Newly Approved Antipsychotics in Patients with a Severe Mental Illness: A Systematic Review and Meta-Analysis

BACKGROUND

Akathisia is a common and distressing movement disorder that can be associated with the use of antipsychotics. It is characterized by a subjective (inner restlessness) and an objective (excessive movements) component. Akathisia can have a negative impact on clinical outcome and even lead to treatment discontinuation. Although medication-induced akathisia is more commonly associated with the use of first-generation antipsychotics (FGAs), it also occurs with second-generation antipsychotics (SGAs), including the newly approved antipsychotics (NAPs) asenapine, lurasidone, iloperidone, cariprazine, and brexpiprazole. Until now, no meta-analysis has been published on the risk of akathisia for all NAPs, as monotherapy or adjunctive treatment, in patients with a severe mental illness.

OBJECTIVE

The primary objectives of this systematic review and meta-analysis were to (i) compare akathisia incidence rates of the NAPs, as monotherapy or adjunctive treatment, in adult patients with a severe mental illness (i.e., schizophrenia, bipolar disorder, or major depressive disorder), using data from published and unpublished randomized controlled trials; and (ii) examine the role of several study characteristics explaining differences in akathisia incidence rates between studies.

METHODS

A systematic literature search, using the PubMed, EMBASE, and Cochrane Library databases (until October 2018), was conducted for English-language placebo- as well as active-controlled clinical trials, including subjective (percentage of patients reporting akathisia) and/or scale-defined medication-induced akathisia incidence rates with NAPs (as monotherapy or as adjunctive treatment) in adult patients with schizophrenia, bipolar disorder, or major depressive disorder. Additional unpublished clinical trials were identified through the ClinicalTrials.gov electronic database. Two meta-analyses (incidence rates and odds ratio [OR] [placebo vs. active] of medication-induced akathisia with NAPs) were performed to obtain an optimal estimation of akathisia risks of adult patients with a severe mental illness under these treatment conditions and to assess the role of study characteristics.

RESULTS

Two hundred and thirteen reports were selected as potentially eligible for our meta-analysis. Of these, 48 met the inclusion criteria. Eight records, identified through the ClinicalTrials.gov database and cross-referencing, and which fulfilled the inclusion criteria, were added, resulting in a total of 56 records (iloperidone = 5, asenapine = 11, lurasidone = 15, brexpiprazole = 13, cariprazine = 12). The estimated weighted mean incidence rate of akathisia was 7.7% (95% confidence interval [CI] 6.5-9.1), with estimates being 3.9% (95% CI 2.4-6.3) for iloperidone, 6.8% (95% CI 5.1-9.0) for asenapine, 10.0% (95% CI 7.4-13.5) for brexpiprazole, 12.7% (95% CI 10.1-16.1) for lurasidone, and 17.2% (95% CI 13.4-22.1) for cariprazine. After Tukey-adjustment for multiple testing, the incidence rate of akathisia was significantly (p < 0.05) lower for iloperidone than for brexpiprazole, lurasidone, and cariprazine. In addition, the incidence rate of akathisia was significantly (p < 0.05) lower for asenapine than for lurasidone and cariprazine. Finally, the incidence rate of akathisia was significantly (p < 0.05) lower for brexpiprazole than for cariprazine. Type of medication (p < 0.0001), diagnosis (p = 0.02), and race (p = 0.0003) significantly explained part of the heterogeneity of the incidence estimates of akathisia between studies. The estimated weighted OR of akathisia under medication, compared with placebo, was 2.43 (95% CI 1.91-3.10). The OR was smallest for iloperidone (OR 1.20; 95% CI 0.42-3.45) and increased for brexpiprazole (OR 2.04; 95% CI 1.09-3.83), asenapine (OR 2.37; 95% CI 1.32-4.27), lurasidone (OR 3.74; 95% CI 2.32-6.02), and cariprazine (OR 4.35; 95% CI 2.80-6.75). Only type of medication (p = 0.03) explained systematic differences in the OR for akathisia between placebo versus active treatment across studies. After Tukey-adjustment for multiple testing, no significant differences between these ORs were found. The severity of akathisia with NAPs generally is mild to moderate, only leading to treatment discontinuation in a minority of cases (< 5%).

CONCLUSIONS

The use of a NAP raises the akathisia risk more than two-fold when compared with patients receiving placebo. Although distinctions between the different NAPs were not clear in placebo-controlled trials, the results of our meta-analyses and systematic review generally indicate that these differences more than likely reflect real differences, with iloperidone showing the most and cariprazine showing the least benign akathisia profile. Moreover, due to patient characteristics and methodological issues, incidence rates of akathisia with NAPs found in this meta-analysis may even be an underestimation of true incidence rates.

Brexpiprazole: A Review in Schizophrenia

Brexpiprazole (Rxulti^®, Rexulti^®) is an oral atypical antipsychotic agent approved for the treatment of schizophrenia in the EU (in adult patients) and the USA, as well as in some other countries, including Japan. Like aripiprazole, it is a partial agonist at dopamine D₂ and serotonin 5-HT_1A receptors and an antagonist at serotonin 5-HT_2A receptors. However, brexpiprazole displays less intrinsic activity at D₂ receptors and, coupled with actions at 5HT_1A, 5HT_2A and noradrenaline α_1B receptors that are at least as potent as its action at D₂ receptors, is predicted to demonstrate a lower propensity for activating adverse events and extrapyramidal symptoms than aripiprazole. Brexpiprazole 2-4 mg/day produced statistically significant and clinically meaningful improvements in overall symptomatology and psychosocial functioning compared with placebo in adults with acute exacerbation of schizophrenia. As maintenance treatment, brexpiprazole 1-4 mg/day significantly delayed the time to relapse compared with placebo in patients who were already stabilized on the drug and was associated with stabilization or continued improvement in patients' symptoms and functioning. Brexpiprazole was generally well tolerated, exhibiting an adverse event profile characterized by a relatively low incidence of activating and sedating adverse effects, small changes in QT interval and metabolic parameters that were not clinically significant, and moderate weight gain. Clinical evidence to date suggests it usefully extends the range of therapeutic options for schizophrenia.

Brexpiprazole for the maintenance treatment of adults with schizophrenia: an evidence-based review and place in therapy

The purpose of this review is to describe the available data for brexpiprazole in the maintenance treatment of schizophrenia. This objective was completed by searching the databases PubMed, Embase, and ClinicalTrials.gov to identify relevant study results presented as papers or abstracts. In summary, brexpiprazole is a new agent in the D₂ partial agonist class that has a unique receptor-binding profile, based in part on high affinity for serotonin 5HT_1A and 5HT_2A receptors, paired with lower intrinsic activity at dopamine D₂ receptors. The average dose used in efficacy and safety studies for the maintenance treatment of schizophrenia ranged from 3.0 and 3.1 mg in the open-label safety studies to 3.6 mg in the double-blind randomized relapse-prevention study. Highlights from the 52-week double-blind placebo-controlled relapse-prevention trial evidenced rates of relapse in the brexpiprazole group of 13.5% vs 38.5% in the placebo group (number needed to treat 4, 95% CI 3-8; P<0.0001). Safety data indicate that brexpiprazole is tolerated well, with rates of discontinuation due to treatment-emergent adverse events that ranged from 5.2% of those taking brexpiprazole in the double-blind maintenance phase of the relapse-prevention trial to 15.3% in a 52-week open-label safety study. In the available trials, there were relatively low rates of akathisia, and the degree of weight gain was similar to that seen in studies with aripiprazole for the treatment of schizophrenia. Positive and Negative Syndrome Scale scores also remained relatively stable in the open-label safety studies. Available data indicate that brexpiprazole is an effective agent for the maintenance treatment of schizophrenia that is overall well tolerated.

Efficacy and metabolic effects of lurasidone versus brexpiprazole in schizophrenia: a network meta-analysis

Aim: To assess the relative efficacy and metabolic effects of lurasidone and brexpiprazole in the acute treatment of schizophrenia. Methods: Five lurasidone and three brexpiprazole trials were identified. In the absence of head-to-head trials, a Bayesian network meta-analysis comparing lurasidone and brexpiprazole was performed. Results: Nonstatistically significant differences in efficacy measures were observed between lurasidone and brexpiprazole. Significant differences favoring lurasidone for weight change (-0.69 kg; 95% CrI: -1.22 to -0.15), total cholesterol (-7.60 mg/dl; 95% CrI: -13.94 to -1.22), and low-density lipoprotein (-6.58 mg/dl; 95% CrI: -12.11 to -1.04) were observed, with a trend indicating half the risk of experiencing ≥7% weight gain. Conclusion: This network meta-analysis suggested that lurasidone had similar efficacy and fewer metabolic effects than brexpiprazole in patients with acute schizophrenia.

Brexpiprazole: A review of a new treatment option for schizophrenia and major depressive disorder

Brexpiprazole is an atypical antipsychotic that works as a partial agonist at serotonin 5-hydroxytryptamine_1A and dopamine D₂ receptors and an antagonist at serotonin 5-hydroxytryptamine_2A. It has US Food and Drug Administration approval for monotherapy treatment of schizophrenia and adjunctive treatment to antidepressants for major depressive disorder. Two phase-3 clinical trials demonstrated efficacy and relatively fair tolerability with regard to adverse effects for each indication. Akathisia was frequently reported in the major depressive disorder trials but less so in the schizophrenia trials. Significant increases in body weight and triglycerides were seen across all studies. Brexpiprazole appears to be a viable option for treating an acute exacerbation of schizophrenia requiring hospitalization or adjunctive treatment of major depressive disorder in patients who showed an inadequate response to 1 to 3 antidepressants. Further clinical trials are warranted to determine the long-term efficacy of brexpiprazole, and comparison trials would be beneficial to establish its place in therapy.

A Long-Term, Open-Label Study to Evaluate the Safety and Tolerability of Brexpiprazole as Maintenance Treatment in Adults with Schizophrenia

BACKGROUND

Brexpiprazole is a serotonin-dopamine activity modulator with efficacy in acute schizophrenia and relapse prevention. The aim of this Phase 3, multicenter study was to assess the long-term safety, tolerability, and efficacy of treatment with brexpiprazole flexible-dose 1-4 mg/d.

METHODS

Patients rolled over into this 52-week open-label study (amended to 26 weeks towards the end) from 3 randomized, double-blind, placebo-controlled Phase 3 studies. De novo patients, not part of the previous studies, were also enrolled. The primary outcome variable was the frequency and severity of treatment-emergent adverse events. Efficacy was assessed as a secondary objective using the Positive and Negative Syndrome Scale and the Personal and Social Performance scale.

RESULTS

A total of 1072 patients was enrolled (952 for 52 weeks and 120 for 26 weeks), 47.4% of whom completed the study. Among patients who took at least one dose of brexpiprazole, 14.6% discontinued due to treatment-emergent adverse events, most commonly schizophrenia (8.8%) and psychotic disorder (1.5%). Treatment-emergent adverse events with an incidence of ≥5% were schizophrenia (11.6%), insomnia (8.6%), weight increased (7.8%), headache (6.4%), and agitation (5.4%). Most treatment-emergent adverse events were mild or moderate in severity. The mean increase in body weight from baseline to week 26 was 1.3 kg and to week 52 was 2.1 kg. There were no clinically relevant findings related to prolactin, lipids, and glucose, or QT prolongation. On average, patients' symptoms and functioning showed continual improvement.

CONCLUSIONS

Treatment with brexpiprazole 1-4 mg/d was generally well tolerated for up to 52 weeks in patients with schizophrenia.

CLINICALTRIALS.GOV IDENTIFIER

NCT01397786 (https://clinicaltrials.gov/show/NCT01397786).

Brexpiprazole: a new leaf on the partial dopamine agonist branch

OBJECTIVES

Brexpiprazole is a new dopamine partial agonist antipsychotic in the same class as aripiprazole. This paper will briefly review brexpiprazole and compare it with aripiprazole.

CONCLUSIONS

Brexpiprazole and aripiprazole are both partial agonists at dopamine D₂, and serotonin 5-HT_1A and antagonists at serotonin 5-HT_2A and noradrenergic α_1B receptors. However, the two drugs are significantly different in potencies at various receptors; neurochemical profiles predict that brexpiprazole may be comparable with aripiprazole in its antipsychotic efficacy but may cause less akathisia, extrapyramidal side effects (EPS) and activation. In pivotal trials brexpiprazole demonstrated antipsychotic efficacy in short and long-term studies; it was also found to be an effective adjunct in patients with major depression resistant to antidepressants. Akathisia can occur early in treatment with brexpiprazole, as can minor weight gain and prolactin elevation. Indirect data extrapolations from pivotal studies suggest that brexpiprazole and aripiprazole have comparable efficacy but brexpiprazole may cause less akathisia. Like aripiprazole, brexpiprazole has been approved in the USA for use in schizophrenia and antidepressant-resistant depression. Although much more clinical experience is needed, brexpiprazole appears to be distinct from aripiprazole and a promising new 'metabolically-friendly' antipsychotic option for treatment of psychoses and mood disorders.

Brexpiprazole in patients with schizophrenia: overview of short- and long-term phase 3 controlled studies

OBJECTIVE

Review efficacy, safety, and tolerability of brexpiprazole in patients with schizophrenia in short- and long-term phase 3 studies.

METHODS

Patients experiencing a current exacerbation of schizophrenia received brexpiprazole in two fixed-dose (2 and 4 mg), 6-week, placebo-controlled studies, one flexible-dose (2-4 mg), 6-week, placebo-control and active reference study, and one fixed-dose (1-4 mg), 52-week, placebo-controlled maintenance study.

RESULTS

The efficacy of brexpiprazole was demonstrated in the two short-term fixed-dose studies with statistically significant improvements from baseline in Positive and Negative Syndrome Scale (PANSS) total score compared with placebo. In the flexible-dose short-term study, treatment with brexpiprazole resulted in numerically greater improvements in PANSS total score than with placebo that approached statistical significance (p=0.056). A meta-analysis of these short-term studies showed a mean change in PANSS total score of -20.1, reflecting a clinically meaningful reduction in symptoms. In the maintenance study, brexpiprazole had a beneficial effect relative to placebo on time to exacerbation of psychotic symptoms/impending relapse (p<0.0001). For all studies, brexpiprazole demonstrated clinically meaningful treatment effects on the Personal and Social Performance scale. Brexpiprazole had a favourable safety profile, with a relatively low prevalence of activating and sedating side effects. Weight gain in the short-term studies was ~1 kg greater than placebo. No safety concerns were observed with brexpiprazole in laboratory values, electrocardiogram, or vital signs.

CONCLUSIONS

Overall, the results indicate brexpiprazole, used either short-term or as part of a long-term maintenance treatment programme, is an efficacious therapy option in adults with schizophrenia and has a favourable safety/tolerability profile.

Safety, tolerability, and risks associated with first- and second-generation antipsychotics: a state-of-the-art clinical review

Since the discovery of chlorpromazine (CPZ) in 1952, first-generation antipsychotics (FGAs) have revolutionized psychiatric care in terms of facilitating discharge from hospital and enabling large numbers of patients with severe mental illness (SMI) to be treated in the community. Second-generation antipsychotics (SGAs) ushered in a progressive shift from the paternalistic management of SMI symptoms to a patient-centered approach, which emphasized targets important to patients - psychosocial functioning, quality of life, and recovery. These drugs are no longer limited to specific Diagnostic and Statistical Manual of Mental Disorders (DSM) categories. Evidence indicates that SGAs show an improved safety and tolerability profile compared with FGAs. The incidence of treatment-emergent extrapyramidal side effects is lower, and there is less impairment of cognitive function and treatment-related negative symptoms. However, treatment with SGAs has been associated with a wide range of untoward effects, among which treatment-emergent weight gain and metabolic abnormalities are of notable concern. The present clinical review aims to summarize the safety and tolerability profile of selected FGAs and SGAs and to link treatment-related adverse effects to the pharmacodynamic profile of each drug. Evidence, predominantly derived from systematic reviews, meta-analyses, and clinical trials of the drugs amisulpride, aripiprazole, asenapine, brexpiprazole, cariprazine, clozapine, iloperidone, lurasidone, olanzapine, paliperidone, quetiapine, risperidone, sertindole, ziprasidone, CPZ, haloperidol, loxapine, and perphenazine, is summarized. In addition, the safety and tolerability profiles of antipsychotics are discussed in the context of the "behavioral toxicity" conceptual framework, which considers the longitudinal course and the clinical and therapeutic consequences of treatment-emergent side effects. In SMI, SGAs with safer metabolic profiles should ideally be prescribed first. However, alongside with safety, efficacy should also be considered on a patient-tailored basis.

Clinical role of brexpiprazole in depression and schizophrenia

Brexpiprazole, a serotonin-dopamine activity modulator, is the second D2 partial agonist to come to market and has been approved for the treatment of schizophrenia and as an adjunctive treatment in major depressive disorder. With less intrinsic activity than aripiprazole at the D2 receptor and higher potency at 5-HT2A, 5-HT1A, and α1B receptors, the pharmacological properties of brexpiprazole suggest a more tolerable side effect profile with regard to akathisia, extrapyramidal dysfunction, and sedation. While no head-to-head data are currently available, double-blind placebo-controlled studies show favorable results, with the number needed to treat (NNT) vs placebo of 6-15 for response in acute schizophrenia treatment and 4 for maintenance. NNT is 12 for response and 17-31 for remission vs placebo in major depression. In schizophrenia trials, treatment-emergent adverse effects (TEAEs) and discontinuation rates due to TEAEs were lower in treatment groups vs placebo (7.1%-9.2% vs 14.7%, respectively). Meanwhile, discontinuation rates due to TEAEs in depression studies were higher in treatment groups vs placebo (1.3%-3.5% vs 0-1.4%, respectively) and appeared dose dependent. Rates of akathisia are lower compared to those with aripiprazole and cariprazine, weight gain is more prominent than with aripiprazole, cariprazine, or ziprasidone, and sedation is less than with aripiprazole but more than with cariprazine. Brexpiprazole target dosing is 2-4 mg in schizophrenia and 2 mg in depression augmentation. Dose adjustments should be considered in hepatic or renal dysfunction and/or in poor cytochrome P450 2D6 metabolizers. While brexpiprazole represents an exciting second entry for D2 partial agonists with positive studies thus far, direct head-to-head comparisons will shed more light on the efficacy and side effect profile of brexpiprazole.

Involvement of presynaptic 5-HT1A receptors in the low propensity of brexpiprazole to induce extrapyramidal side effects in rats

Previous studies have shown that partial and full 5-HT_1A receptor agonists reduce antipsychotic-induced catalepsy. Consequently, some antipsychotics combining balanced efficacy between dopamine (DA) D₂ antagonism or partial agonism and 5-HT_1A receptor agonism have a low propensity to induce extrapyramidal side effects (EPS), as reflected by low cataleptogenic activity in rodents. In the present experiments, we attempted to explore the importance of pre- and postsynaptic 5-HT_1A agonistic properties of brexpiprazole and aripiprazole in the context of neurological side-effect liabilities. Additional measures of prefrontal cortical serotonin (5-HT) and DA levels using microdialysis were used to support that brexpiprazole has a preferential agonist effect on presynaptic 5-HT_1A receptors. Brexpiprazole (3.0 and 10mg/kg, p.o.) as well as aripiprazole (8.0 and 30mg/kg, p.o.) failed to induce catalepsy in rats. Brexpiprazole (10mg/kg, p.o.) significantly reduced the cataleptic response induced by haloperidol (0.63mg/kg, s.c.), while aripiprazole (1.0-100mg/kg, p.o.) failed to reverse the effect of haloperidol and only showed a numeric decrease at 10mg/kg, (p.o.). When 5-HT_1A receptors were blocked by the selective antagonist, WAY100635 (1.0mg/kg, s.c.), cataleptogenic properties of brexpiprazole (10mg/kg; p.o), but not aripiprazole (8.0 and 30mg/kg, p.o.) were unmasked. The ("biased") 5-HT_1A receptor agonists F15599 (postsynaptic preference) and F13714 (presynaptic preference) had differential effects on haloperidol-induced catalepsy: F13714 (0.16mg/kg, s.c.) counteracted catalepsy, whereas F15599 (0.040mg/kg, s.c.) had no significant effect at regionally-selective doses. These data support a role of presynaptic 5-HT_1A receptors in the anticataleptic effect of brexpiprazole. The selective 5-HT_2A antagonist M100907 (0.10mg/kg, s.c.) had no effect on haloperidol-induced catalepsy, arguing against a major role of 5-HT_2A receptors in the cataleptogenic profile of brexpiprazole. The findings with brexpiprazole were supported using microdialysis studies: Brexpiprazole (3.0 and 10mg/kg, p.o.) decreased extracellular 5-HT levels in the medial prefrontal cortex (mPFC), while it failed to affect extracellular DA in the same samples, suggesting that the 5-HT_1A agonist properties of brexpiprazole may be preferentially presynaptic. In conclusion, these results confirm that brexpiprazole and aripiprazole have low propensities to induce EPS. However, the low EPS risk of brexpiprazole is more likely dependent on its agonist properties on presynaptic 5-HT_1A receptors, while that of aripiprazole is less sensitive to 5-HT_1A receptor antagonism.

Current Data on and Clinical Insights into the Treatment of First Episode Nonaffective Psychosis: A Comprehensive Review

Implementing the most suitable treatment strategies and making appropriate clinical decisions about individuals with a first episode of psychosis (FEP) is a complex and crucial task, with relevant impact in illness outcome. Treatment approaches in the early stages should go beyond choosing the right antipsychotic drug and should also address tractable factors influencing the risk of relapse. Effectiveness and likely metabolic and endocrine disturbances differ among second-generation antipsychotics (SGAs) and should guide the choice of the first-line treatment. Clinicians should be aware of the high risk of cardiovascular morbidity and mortality in schizophrenia patients, and therefore monitoring weight and metabolic changes across time is mandatory. Behavioral and counseling interventions might be partly effective in reducing weight gain and metabolic disturbances. Ziprasidone and aripiprazole have been described to be least commonly associated with weight gain or metabolic changes. In addition, some of the SGAs (risperidone, amisulpride, and paliperidone) have been associated with a significant increase of plasma prolactin levels. Overall, in cases of FEP, there should be a clear recommendation of using lower doses of the antipsychotic medication. If no or minimal clinical improvement is found after 2 weeks of treatment, such patients may benefit from a change or augmentation of treatment. Clinicians should provide accurate information to patients and relatives about the high risk of relapse if antipsychotics are discontinued, even if patients have been symptom free and functionally recovered on antipsychotic treatment for a lengthy period of time.

Brexpiprazole: A Review in Schizophrenia

Oral brexpiprazole (Rexulti(®)) is a partial dopamine D2 agonist, which also has activity at several other receptors. This article reviews the pharmacological properties of brexpiprazole and its clinical efficacy and tolerability in patients with schizophrenia; its use in patients with major depressive disorder is beyond the scope of this review. Brexpiprazole 2-4 mg/day was generally effective in short-term, phase III studies at improving Positive and Negative Symptom Scale scores and other schizophrenia symptoms in patients with acute schizophrenia. Moreover, maintenance treatment with brexpiprazole 1-4 mg/day was associated with a significantly longer time to exacerbation of disease or impending relapse than placebo. The drug was well tolerated in clinical trials, with most serious adverse events in the short term being associated with the underlying disorder. Overall, oral brexpiprazole is a useful treatment option for the treatment of patients with schizophrenia.

Adjunctive Brexpiprazole: A Review in Major Depressive Disorder

Brexpiprazole (Rexulti(®)) is a serotonin-dopamine activity modulator, with a unique receptor binding profile and low intrinsic D2 activity suggestive of a lower potential than aripiprazole to cause activation-like adverse effects, such as akathisia. The drug was recently approved by the US FDA for adjunctive therapy with antidepressant treatment (ADT) in patients with major depressive disorder (MDD). In two phase III trials, adjunctive oral brexpiprazole 2 or 3 mg once daily was more effective than monotherapy with ADT in improving depressive symptoms in adults with MDD who demonstrated an incomplete response to previous treatment with ADT. Adjunctive brexpiprazole was generally well tolerated in clinical trials, which included treatment periods of up to 52 weeks. Results of ongoing trials should help position the drug in the treatment of MDD. In the meantime, brexpiprazole provides a valid option for patients with persistent symptoms despite standard antidepressant therapy.