The effects of brexpiprazole and aripiprazole on body weight as monotherapy in patients with schizophrenia and as adjunctive treatment in patients with major depressive disorder: an analysis of short-term and long-term studies

Pharmacological Strategies for Bipolar Disorders in Acute Phases and Chronic Management with a Special Focus on Lithium, Valproic Acid, and Atypical Antipsychotics

Bipolar disorders (BDs) are a heterogeneous group of severe affective disorders generally described by the alternation of (hypo)manic, depressive, and mixed phases, with euthymic intervals of variable duration. BDs are burdened with high psychiatric and physical comorbidity, increased suicide risk and reduced life expectancy. In addition, BDs can progress into complicated forms (e.g., mixed states, rapid/irregular cycling), which are more difficult to treat and often require personalized pharmacological combinations. Mood stabilizers, particularly Lithium and Valproic acid (VPA), still represent the cornerstones of both acute and chronic pharmacotherapies of BDs. Lithium is the gold standard in BD-I and BDII with typical features, while VPA seems more effective for atypical forms (e.g., mixed-prevalence and rapid-cycling). However, despite appropriate mood stabilization, many patients show residual symptoms, and more than a half recur within 1-2 years, highlighting the need of additional strategies. Among these, the association of atypical antipsychotics (AAPs) with mood stabilizers is recurrent in the treatment of acute phases, but it is also being growingly explored in the maintenance pharmacotherapy. These combinations are clinically more aggressive and often needed in the acute phases, whereas simplifying pharmacotherapies to mood stabilizers only is preferable in the long-term, whenever possible. When mood stabilizers are not enough for maintenance treatment, Quetiapine and, less consistently, Aripiprazole have been proposed as the most advisable adjunctive strategies, for their safety and tolerability profiles. However, in view of the increased risk of serious adverse effects, a careful patient-centered balance between costs and benefits is mandatory.

Prevalence and impact of antipsychotic discontinuation among commercially-insured patients with bipolar disorder

BACKGROUND

Antipsychotic discontinuation is common among patients with bipolar disorder, especially when psychotic symptoms are remitted. This analysis describes the prevalence, predictors, and economic impact of antipsychotic discontinuation among patients with bipolar disorder.

METHODS

A retrospective, observational study was conducted using administrative claims data in the IBM MarketScan Commercial Database. Patients with ≥1 claim with a diagnosis for bipolar disorder (manic or mixed) and newly-initiating antipsychotic therapy between 1 January 2011 and 30 June 2016 were included. Baseline characteristics were assessed in the 12 months prior to the initiation. Outcomes were assessed during a 24-month follow-up. Discontinuation of antipsychotic therapy was utilized as a predictor of healthcare costs in models adjusted for baseline characteristics. Using limited set of variables in the claims database, predictors of discontinuation were also assessed.

RESULTS

A total of 18,259 commercially-insured patients were identified as initiators of antipsychotics. Common comorbidities among the cohorts included major depressive disorder and dyslipidemia. Discontinuation was very common among these patients (85%). Major depressive disorder, drug abuse, and other substance abuse/dependency were predictive of discontinuation. Controlling for differences in baseline characteristics, discontinuation was associated with 33% higher inpatient and emergency visit costs (p <.001) among those using these services, and 24% higher total healthcare costs (p <.001) for the overall cohort.

CONCLUSIONS

Most patients with bipolar mania or mixed states discontinue antipsychotic treatment in less than 2 years. Antipsychotic discontinuation contributes to excess healthcare costs. Future research focusing on the reasons for discontinuation and tailoring disease management based on comorbidities may inform adherence improvement initiatives.

Cardiometabolic outcomes among schizophrenia patients using antipsychotics: the impact of high weight gain risk vs low weight gain risk treatment

OBJECTIVE

Evaluate the prevalence of cardiometabolic conditions among schizophrenia patients before and incidence after initiation of high (HWGR) and low weight gain risk (LWGR) antipsychotic (AP) regimens.

METHODS

A retrospective observational cohort study was conducted using administrative claims data from the IBM® MarketScan Commercial and Multi-State Medicaid Databases. Patients with > 1 medical claim with a diagnosis for schizophrenia and newly initiating AP therapy between 1/1/11-6/30/16 were included. Baseline characteristics were assessed in the 12-months before AP initiation; outcomes over 24-months following AP initiation. Patients were characterized by the AP regimen initiated at the index date. Adherence was defined by a medication possession ratio > 0.8 (medication on hand for 80% of follow-up). Multivariate modeling identified predictors of index AP weight gain risk profile and post-index dyslipidemia.

RESULTS

Two thousand seven hundred forty-eight commercially-insured and 8,748 Medicaid patients met the inclusion criteria. A majority of patients initiated on atypical AP and approximately 30% were adherent to their index AP regimen. Within both payers, patients indexing on LWGR AP regimens were more likely to have pre-index diagnoses of cardiometabolic conditions including hypertension, dyslipidemia, and diabetes. Significant predictors of post-index dyslipidemia included AP adherence and pre-index diabetes. Within both payers, odds of initiating HWGR AP regimens were higher among patients with evidence of drug abuse.

CONCLUSIONS

There is unmet need for reducing cardiometabolic consequences for patients on AP therapy and this analysis provides evidence that cardiometabolic conditions often develop during early stages of AP therapy. However, this does not appear to be related to the weight gain risk profile of the AP regimen.

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.

Brexpiprazole for the Treatment of Schizophrenia and Major Depressive Disorder: A Comprehensive Review of Pharmacological Considerations in Clinical Practice

Mood and psychotic disorders are a group of illnesses that affect behavior and cognition. Schizophrenia is characterized by positive symptoms, such as delusions and hallucinations, as well as negative symptoms. Major depressive disorder (MDD) is a mood disorder that affects the patient's emotions, energy, and motivation. Brexpiprazole works as a partial agonist at serotonin 5-hydroxytryptamine1A and dopamine D2 receptors and an antagonist at serotonin 5-hydroxytryptamine2A. Schizophrenia and MDD have a wide range of risk factors, both biological and environmental. Third generation antipsychotics, which include brexpiprazole, are the latest group of drugs to reach the market, demonstrating efficacy and tolerability. Patients with acute schizophrenia have responded well to brexpiprazole. In this regard, in patients who have MDD plus anxiety symptoms, brexpiprazole can be effective as an adjunctive therapy and can reduce anxiety symptoms. In summary, brexpiprazole has proved to be an effective alternative to typical or first and second-generation atypical antipsychotics.

Effect of Switching to Brexpiprazole on Plasma Homovanillic Acid Levels and Antipsychotic-Related Side Effects in Patients with Schizophrenia or Schizoaffective Disorder

OBJECTIVE

Although switching antipsychotics is a common strategy in the treatment of schizophrenia, caution is needed because of the risk of worsening of psychosis, particularly when switching to a dopamine D2 partial agonist. Homovanillic acid (HVA), a dopamine metabolite, is thought to be a possible indicator of the response to antipsychotics. We examined the effects of switching to brexpiprazole monotherapy from other antipsychotics on plasma HVA levels and side effects during maintenance treatment of schizophrenia.

METHODS

The antipsychotics of 37 Japanese patients with schizophrenia or schizoaffective disorder were switched to brexpiprazole for the improvement of side effects. We evaluated clinical symptoms and extrapyramidal symptoms (EPS) and took fasting blood samples at baseline and endpoint (eight weeks after completing the switch) to measure plasma levels of HVA, prolactin, and metabolic parameters.

RESULTS

Switching to brexpiprazole significantly decreased the Drug-Induced Extrapyramidal Symptoms Scale total score (p=0.008), prolactin levels (p<0.001), body weight (p=0.046), and body-mass index (p=0.034), and increased HDL cholesterol (p=0.008). On the other hand, switching to brexpiprazole did not change plasma levels of HVA or Positive and Negative Syndrome Scale scores.

CONCLUSION

Switching to brexpiprazole significantly improved EPS, high prolactin levels, and metabolic side effects without elevating plasma HVA levels. Brexpiprazole may stabilize dopaminergic neural transmission and could be a useful strategy to decrease the burden in patients with schizophrenia during the maintenance phase. Because of the small sample size, further studies with larger sample sizes are needed to confirm and extend our results.

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.

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.

Long-Term Efficacy and Safety of Brexpiprazole in Elderly Japanese Patients with Schizophrenia: A Subgroup Analysis of an Open-Label Study

PURPOSE

This study was performed to assess the long-term efficacy, safety, and tolerability of brexpiprazole in elderly Japanese patients with schizophrenia.

METHODS

This is a post hoc analysis of a previous open-label study conducted over 56 weeks which consisted of two consecutive phases: a 4-week switching period and a 52-week open-label period. Mean change in the Positive and Negative Syndrome Scale (PANSS) total score, response rates, number and incidence of treatment-emergent adverse events (TEAEs), and other safety parameters were analyzed using descriptive statistics based on age group (elderly, ≥65 and non-elderly, <65).

RESULTS

This post hoc analysis included 208 de novo patients of which 33 were elderly. The continuation rate in elderly patients was 54.5%, and the mean daily dose and treatment duration of brexpiprazole in elderly patients at week 56 were similar to those of non-elderly patients. The mean change in the PANSS total score from the baseline to week 56 was -13.8 in elderly patients and this improvement was maintained throughout the open-label phase. This outcome was comparable to that of the non-elderly patients (-9.0). The incidence rate of TEAEs was 97.0% in elderly patients and 82.3% in non-elderly patients. Most of the TEAEs were either mild (75.8%) or moderate (18.2%) in severity in the elderly patients and the incidence of TEAEs leading to discontinuation was lower in elderly (9.1%) than in non-elderly patients (13.1%). The most commonly observed adverse events in elderly patients were nasopharyngitis (30.3%) and worsening of schizophrenia (27.3%). The safety profiles in both groups were similar.

CONCLUSION

Brexpiprazole was shown to be safe and effective in the treatment of elderly Japanese patients with schizophrenia.

Major Depressive Disorder (MDD) and Schizophrenia- Addressing Unmet Needs With Partial Agonists at the D2 Receptor: A Review

Second-generation antipsychotics are common candidates for the adjunctive treatment of major depressive disorder and for the treatment of schizophrenia. However, unmet needs remain in the treatment of both disorders. Considering schizophrenia, antipsychotics are the most common treatment and have demonstrated good efficacy. Still, side effects of these treatments are commonly reported and may impact adherence to the medication and functioning in patients with schizophrenia. Regarding major depressive disorder, despite the availability of several classes of antidepressants, many patients do not achieve remission. Adjunctive treatment with antipsychotics may improve clinical and functional outcomes. Compared with dopamine D2 receptor antagonism that is exhibited by most antipsychotics, partial agonism may result in improved outcomes in major depressive disorder and in schizophrenia. Aripiprazole, cariprazine, and brexpiprazole have partial agonism at the dopamine D2 receptor and could potentially overcome limitations associated with D2 antagonism. The objectives of this review were (1) to discuss the goal of treatment with second-generation antipsychotics in major depressive disorder and schizophrenia, and the clinical factors that should be considered, and (2) to examine the short- and long-term existing data on the efficacy and safety of D2 receptor partial agonists (aripiprazole, cariprazine, and brexpiprazole) in the adjunctive treatment of major depressive disorder and in the treatment of schizophrenia.

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.

A Long-Term, Open-Label Study to Evaluate the Safety and Tolerability of Brexpiprazole as Adjunctive Therapy in Adults With Major Depressive Disorder

BACKGROUND

Long-term treatment is recommended in major depressive disorder (MDD) to prevent relapse and to restore functioning. The aim of this study (Orion; NCT01360866) was to assess the long-term safety, tolerability, and efficacy of open-label treatment with adjunctive brexpiprazole in adult patients with MDD.

METHODS

Patients rolled over into this 52-week study (amended to 26 weeks) from 3 randomized, double-blind, placebo-controlled studies. Patients received brexpiprazole 0.5 to 3 mg/d (flexible dose) adjunct to their current antidepressant treatment. The primary outcome variable was the frequency and severity of treatment-emergent adverse events (TEAEs). Efficacy was assessed as a secondary objective using clinical rating scales.

RESULTS

A total of 2944 patients were enrolled (1547 for 52 weeks, 1397 for 26 weeks), of whom 1895 (64.4%) completed the study. The TEAEs with incidence of 5% or greater were weight increase (17.7%), somnolence (8.0%), headache (7.2%), akathisia (6.7%), increased appetite (6.3%), insomnia (6.3%), fatigue (6.1%), viral upper respiratory tract infection (5.4%), and anxiety (5.2%). Most TEAEs were mild or moderate in severity. The mean increase in body weight was 2.7 kg to week 26 and 3.2 kg to week 52; 25.8% of patients had a weight increase of 7% or greater at any postbaseline visit. There were no clinically relevant findings related to extrapyramidal symptoms, prolactin, lipids, or glucose. Patients' symptoms and functioning showed continual improvement.

CONCLUSIONS

Adjunctive treatment with open-label brexpiprazole 0.5 to 3 mg/d was generally well tolerated for up to 52 weeks in patients with MDD and was associated with continued improvement in efficacy measures and functional outcomes.

Effect of Brexpiprazole on Prolactin: An Analysis of Short- and Long-Term Studies in Schizophrenia

BACKGROUND

Hyperprolactinemia is an undesirable effect of most antipsychotics because of D2-receptor blockade. We assessed the effect of the D2-receptor partial agonist brexpiprazole on prolactin, based on pooled data from three 6-week, randomized, placebo-controlled studies and two open-label extension studies in patients with schizophrenia.

METHODS

In the short-term studies, patients received 0.25, 1, 2, 4 mg brexpiprazole or placebo; or flexible-dose brexpiprazole (2-4 mg/d), placebo, or active reference. The extension studies were 52-week, flexible-dose (1-4 mg/d) studies. We studied changes from baseline and shifts in prolactin status in patients with normal or elevated prolactin levels at baseline, and prolactin-related treatment-emergent adverse events (TEAEs).

RESULTS

Median changes from baseline to week 6 in brexpiprazole-treated patients in short-term studies were as follows: 3.63 ng/mL (females), 0.26 ng/mL (males); placebo: -2.15 ng/mL (females), -1.08 ng/mL (males).Median changes from baseline to week 52 in long-term studies were 0.60 ng/mL (females) and 0.18 ng/mL (males). Prolactin levels in patients with baseline values greater than 1× upper limit of normal tended to decrease over time regardless of previous treatment.The proportions of brexpiprazole-treated patients with greater than 3× upper limit of normal postbaseline prolactin values in short-term studies were as follows: 1.5% (females), 1.6% (males); placebo: 3.6% (females), 3.4% (males). Corresponding figures in long-term studies were 5.3% (females) and 2.0% (males).In short-term studies, the incidence of prolactin-related TEAEs was 1.8% for brexpiprazole and 0.6% for placebo. In long-term studies, the incidence of prolactin-related TEAEs was 1.7%.

CONCLUSIONS

Small changes in prolactin levels, low proportions of patients with postbaseline elevated prolactin values, and low incidence of prolactin-related TEAEs were observed after treatment with brexpiprazole.

Brexpiprazole: a step forward for precision medicine in resistant depression

INTRODUCTION

Resistant depression is still a common and burdensome issue and there is an urgent need for new and effective adjunctive treatments. Areas covered: In this paper, the author discusses the background, trial design, results and implications of a recent study (NCT02196506, Sirius study) which confirmed the possible benefit of brexpiprazole as adjunctive treatment in depressed subjects with inadequate benefit from first line treatments. As secondary aims, the study confirmed the effects in subjects with minimal benefit from standard treatments and in subjects with anxious distress. Despite some reported side effects such as akathisia, restlessness, and increased weight, the treatment was well tolerated. Expert opinion: The unique pharmacodynamic profile of brexpiprazole, in terms of reduced dopamine intrinsic stimulation and a range of other more anxiolytic receptor effects, suggests that brexpiprazole should be preferred in specific subpopulations, particularly where a more sedative profile is needed. Indeed, this study suggests another step in the direction of precision medicine.