The efficacy of cariprazine on cognition: a post hoc analysis from phase II/III clinical trials in bipolar mania, bipolar depression, and schizophrenia.

OBJECTIVE: To investigate the effect of cariprazine on cognitive symptom change across bipolar I disorder and schizophrenia. METHODS: Post hoc analyses of 3- to 8-week pivotal studies in bipolar I depression and mania were conducted; one schizophrenia trial including the Cognitive Drug Research System attention battery was also analyzed. Outcomes of interest: Montgomery-Åsberg Depression Rating Scale [MADRS], Functioning Assessment Short Test [FAST], Positive and Negative Syndrome Scale [PANSS]). LSMDs in change from baseline to end of study were reported in the overall intent-to-treat population and in patient subsets with specified levels of baseline cognitive symptoms or performance. RESULTS: In patients with bipolar depression and at least mild cognitive symptoms, LSMDs were statistically significant for cariprazine vs placebo on MADRS item 6 (3 studies; 1.5 mg=-0.5 [P<.001]; 3 mg/d=-0.2 [P<.05]) and on the FAST Cognitive subscale (1 study; 1.5 mg/d=-1.4; P=.0039). In patients with bipolar mania and at least mild cognitive symptoms, the LSMD in PANSS Cognitive subscale score was statistically significant for cariprazine vs placebo (3 studies; -2.1; P=.001). In patients with schizophrenia and high cognitive impairment, improvement in power of attention was observed for cariprazine 3 mg/d vs placebo (P=.0080), but not for cariprazine 6 mg/d; improvement in continuity of attention was observed for cariprazine 3 mg/d (P=.0012) and 6 mg/d (P=.0073). CONCLUSION: These post hoc analyses provide preliminary evidence of greater improvements for cariprazine vs placebo across cognitive measures in patients with bipolar I depression and mania, and schizophrenia, suggesting potential benefits for cariprazine in treating cognitive symptoms.

The burden of caring for someone with schizophrenia: A cross country report from Bulgaria, the Czech Republic, Hungary and Russia.

INTRODUCTION: People with schizophrenia often need long-term support in their everyday life. Thus, caregivers are vital factors to support their recovery and long-term functioning. In turn, however, the caregiver role is highly burdensome and may lead to severe distress and burnout, imposing further hardness on patients and their family. The aim of this paper was to map the caregivers' situation and their possible needs in Bulgaria, the Czech Republic, Hungary, and Russia. METHODS: 225 caregivers of schizophrenic patients completed a questionnaire in Bulgaria (n=50), the Czech Republic (n=50), Hungary (n=50) and Russia (n=75) about their sociodemographic status, financial, emotional and subjective challenges that arise from the caregiver duty. RESULTS: Caregivers are mainly married (56%), women (72%) entering their 50's, working full time (48%). The average time they spend taking care of someone with schizophrenia is 26 hours weekly. This duty often limits their indepen - dence (59%), recreational activities (56%), financial security (47%) and social life (47%). Thirty-nine percentage reported health-related issues, while sadness and anxiety were also commonly experienced. Caregivers felt left alone with their struggles (56%), longing for both disease-related information and self-help support. As a result, 21% felt fully or mostly dissatisfied with their life. CONCLUSION: Taking care of someone with schizophrenia represents a high burden, affecting one's social and economic status, as well as mental and physical health. Caregivers often feel alone with their struggles and would welcome tailored support to help them cope with the multidimensional burden they carry.

[Cariprazine, a new type - dopamine D3 receptor preferring - partial agonist atypical antipsychotic for the treatment of schizophrenia and the primary negative symptoms]. / Kariprazin, egy új típusú ­ dopamin D3 receptort preferáló ­ parciális agonista atípusos antipszichotikum a szkizofrénia és primer negatív tüneteinek kezelésére.

Dopamine D2 receptor partial agonists represent a new generation of atypical antipsychotics. Cariprazine, which has received centralized market authorization from the European Medicines Agency in 2017 for the treatment of adult patients with schizophrenia (including those with predominant negative symptoms of schizophrenia) differs from the other two partial agonist antipsychotics aripiprazole and brexpiprazole due to its unique features. Cariprazine is a dopamine D3 preferring D3/D2 partial agonist with very similar dopamine receptor subtype selectivity as dopamine. It has proven efficacy in the treatment of positive and negative symptoms of schizophrenia, as well as for relapse prevention. Further phase-3 clinical studies proved the efficacy of cariprazine in the acute treatment of manic or mixed episodes associated with bipolar I disorder, as well as in bipolar depression. For the adjunctive treatment of major depressive disorder, phase 3 studies are in progress.

Cariprazine versus risperidone monotherapy for treatment of predominant negative symptoms in patients with schizophrenia: a randomised, double-blind, controlled trial.

BACKGROUND: Although predominant negative symptoms of schizophrenia can be severe enough to cause persistent impairment, effective treatment options are lacking. We aimed to assess the new generation antipsychotic cariprazine in adult patients with predominant negative symptoms. METHODS: In this randomised, double-blind, phase 3b trial, we enrolled adults aged 18-65 years with long-term (>2 year), stable schizophrenia and predominant negative symptoms (>6 months) at 66 study centres (mainly hospitals and university clinics, with a small number of private practices) in 11 European countries. Patients were randomly assigned (1:1) by an interactive web response system to 26 weeks of monotherapy with fixed-dose oral cariprazine (3 mg, 4·5 mg [target dose], or 6 mg per day) or risperidone (3 mg, 4 mg [target dose], or 6 mg per day); previous medication was discontinued over 2 weeks. The primary outcome was change from baseline to week 26 or end of treatment on the Positive and Negative Syndrome Scale factor score for negative symptoms (PANSS-FSNS) analysed in a modified intention-to-treat population of patients who had follow-up assessments within 5 days after last receipt of study drugs with a mixed-effects model for repeated measures. Safety was assessed in all patients who received at least one dose of study drug. This study is registered with EudraCT, number 2012-005485-36. FINDINGS: Between May 27, 2013, and Nov 17, 2014, 533 patients were screened and 461 (86%) patients were randomised to treatment (230 for cariprazine and 231 for risperidone); 460 were included in the safety population (one patient discontinued before study drug intake). 227 (99%) of 230 patients in the cariprazine group and 229 (99%) of 230 patients in the risperidone group were included in the modified intention-to-treat population (178 [77%] in each group completed 26 weeks of treatment). Mean daily doses were 4·2 mg (SD 0·6) for cariprazine and 3·8 mg (0·4) for risperidone. Treatment-emergent adverse events (eg, insomnia, akathisia, worsening of schizophrenia, headache, anxiety) were reported in 123 (54%) patients treated with cariprazine and 131 (57%) patients treated with risperidone. Use of cariprazine led to a greater least squares mean change in PANSS-FSNS from baseline to week 26 than did risperidone (-8·90 points for cariprazine vs -7·44 points for risperidone; least squares mean difference -1·46, 95% CI -2·39 to -0·53; p=0·0022; effect size 0·31). One patient in the risperidone group died of a cause regarded as unrelated to treatment. INTERPRETATION: Our results support the efficacy of cariprazine in the treatment of predominant negative symptoms of schizophrenia. FUNDING: Gedeon Richter Plc.

Evaluation of the long-term safety and tolerability of cariprazine in patients with schizophrenia: results from a 1-year open-label study.

OBJECTIVE: Cariprazine, a dopamine D3/D2 partial agonist atypical antipsychotic with preferential binding to D3 receptors, is approved for the treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder. The efficacy and safety of cariprazine was established in three randomized, double-blind, placebo-controlled, 6-week trials in patients with acute exacerbation of schizophrenia. This 53-week study evaluated the long-term safety and tolerability of cariprazine in patients with schizophrenia. METHODS: This was a multicenter, open-label, flexible-dose study of cariprazine 3-9 mg/d in adults with schizophrenia. Participants included new patients and patients who had completed one of two phase III lead-in studies (NCT01104766, NCT01104779). Eligible patients entered a no-drug screening period of up to 1 week followed by 48 weeks of flexibly dosed, open-label cariprazine treatment (3-9 mg/d) and 4 weeks of safety follow-up. RESULTS: A total of 586 patients received open-label cariprazine treatment, ~39% of whom completed the study. No unexpected safety issues or deaths were reported. The most common (≥10%) adverse events (AEs) observed were akathisia (16%), headache (13%), insomnia (13%), and weight gain (10%). Serious AEs occurred in 59 (10.1%) patients, and 73 (12.5%) patients discontinued the study due to AEs during open-label treatment. Mean changes in metabolic, hepatic, and cardiovascular parameters were not considered clinically relevant. Mean body weight increased by 1.5 kg during the study, prolactin levels decreased slightly, and measures of efficacy remained stable. CONCLUSIONS: Long-term cariprazine treatment at doses up to 9 mg/d appeared to be generally safe and well tolerated in patients with schizophrenia.

The safety and tolerability of cariprazine in long-term treatment of schizophrenia: a post hoc pooled analysis.

BACKGROUND: Schizophrenia is a chronic and debilitating neuropsychiatric disorder that often requires long-term pharmacotherapy to manage symptoms and prevent relapse. Cariprazine is a potent dopamine D3 and D2 receptor partial agonist that is FDA-approved in the US for the treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder in adults; the recommended dose range is 1.5-6 mg/d. METHODS: To further characterize the long-term safety of cariprazine, data from two 48-week open-label, flexible-dose extension studies were pooled for post hoc analyses. Outcomes were evaluated in the pooled safety population (patients who received ≥1 dose of cariprazine during an open-label extension period); findings were summarized using descriptive statistics for the overall cariprazine group and in modal daily dose groups (1.5-3, 4.5-6, and 9 mg/d). RESULTS: Of the 679 patients in the overall cariprazine safety population, 40.1% completed the study. The only adverse events (AEs) leading to discontinuation of ≥2% of patients in any dose group were akathisia, worsening of schizophrenia, and psychotic disorder. Treatment-emergent AEs (TEAEs) of akathisia, insomnia, weight increased, and headache were reported in ≥10% of the overall population. Mean prolactin levels decreased in all dose groups (overall, -15.4 ng/mL). Clinically insignificant changes in aminotransferase levels and alkaline phosphatase were observed; no dose-response relationship was observed across groups. Mean total (-5.3 mg/dL), low-density lipoprotein (-3.5 mg/dL), and high-density lipoprotein (-0.8 mg/dL) cholesterol levels decreased; no dose-response relationship was observed for metabolic parameters. Mean change in body weight was 1.58 kg; body weight increase and decrease ≥7% occurred in 27% and 11% of patients, respectively. Mean changes in cardiovascular parameters, including blood pressure and pulse, were generally not considered clinically significant. EPS-related TEAEs that occurred in ≥5% of patients were akathisia, tremor, restlessness, and extrapyramidal disorder. CONCLUSION: In these post hoc pooled analyses of data from 2 long-term open-label studies, treatment with cariprazine was generally safe and well tolerated. Results support the safety and tolerability of cariprazine within the FDA-recommended dose range of 1.5-6 mg/d for schizophrenia. CLINICAL TRIALS REGISTRATION: NCT01104792, NCT00839852.

Global improvement with cariprazine in the treatment of bipolar I disorder and schizophrenia: A pooled post hoc analysis.

INTRODUCTION: Global rating scale measures are useful for assessing the clinical relevance of patient change. Cariprazine, a dopamine D3 and D2 receptor partial agonist, is FDA-approved for the adult treatment of acute manic/mixed episodes of bipolar I disorder and schizophrenia. Post hoc evaluations of Clinical Global Impressions-Severity (CGI-S) scores from the cariprazine pivotal trials in both indications were conducted. METHODS: Data from 3 bipolar mania and 3 schizophrenia trials were pooled by indication (bipolar disorder = 1033; schizophrenia = 1466). Cariprazine- and placebo-treated patients were categorised by baseline CGI-S scores; the proportion of patients who improved from more severe categories at baseline to less severe categories at end-point was evaluated using a logistic regression model. Correlations between Young Mania Rating Scale and Positive and Negative Syndrome Scale total score changes and category shifts were also evaluated. RESULTS: In both disease states, more cariprazine- than placebo-treated patients had improved CGI-S scores at end-point; more placebo-treated patients had worse end-point scores. More cariprazine- vs placebo-treated patients shifted from the extremely/severely ill to mildly ill/better category (bipolar disorder = 55% vs 36%, odds ratio [OR] = 2.1; P = .09; schizophrenia = 42% vs 18%, OR = 3.4, P<.01). ORs was statistically significant in favour of cariprazine in shifts from marked and moderate illness to borderline/normal in both indications (P < .05). Correlations between rating scale improvement and category shift were greatest in patients with extreme/severe baseline illness for bipolar disorder (-0.853) and schizophrenia (-0.677). CONCLUSIONS: Post hoc analyses showed that more cariprazine- than placebo-treated patients with bipolar mania or schizophrenia had statistically significant and clinically meaningful CGI-S improvement.

Efficacy and Safety of Cariprazine in Acute Exacerbation of Schizophrenia: Results From an International, Phase III Clinical Trial.

This phase III study evaluated the efficacy and safety of cariprazine, a dopamine D3 and D2 receptor partial agonist with preferential binding to D3 receptors, in patients with acute exacerbation of schizophrenia. Patients were randomized to 6-week double-blind treatment with placebo, cariprazine 3 to 6 mg/d, or cariprazine 6 to 9 mg/d. Primary and secondary efficacy: change from baseline to week 6 in Positive and Negative Syndrome Scale total and Clinical Global Impressions-Severity scores, respectively, analyzed using a mixed-effects model for repeated measures adjusting for multiple comparisons. Safety included treatment-emergent adverse events, clinical laboratory values, vital signs, electrocardiograms, ophthalmologic examination, Columbia-Suicide Severity Rating Scale, and extrapyramidal symptom scales. In the Safety Population (placebo, n = 147; cariprazine 3-6 mg/d, n = 151; cariprazine 6-9 mg/d, n = 148), 60.5% of patients completed the study. At week 6, statistically significant least squares mean differences in favor of cariprazine versus placebo were observed for Positive and Negative Syndrome Scale total score (3-6 mg/d: -6.8, P = 0.003; 6-9 mg/d: -9.9, P < 0.001) and Clinical Global Impressions-Severity (3-6 mg/d: -0.3, P = 0.012; 6-9 mg/d: -0.5, P < 0.001). Common treatment-emergent adverse events (≥5% and twice the rate of placebo) in both cariprazine groups were akathisia, extrapyramidal disorder, and tremor; most were mild to moderate in severity. Mean changes in metabolic parameters were generally small and similar between groups. Prolactin levels decreased in all groups. In conclusion, cariprazine 3 to 6 and 6 to 9 mg/d versus placebo demonstrated significant improvement on primary and secondary efficacy parameters. Cariprazine was generally well tolerated. These results suggest that cariprazine may be a new and effective treatment for schizophrenia.

The efficacy and tolerability of cariprazine in acute mania associated with bipolar I disorder: a phase II trial.

OBJECTIVES: Cariprazine, an orally active and potent dopamine D3 and D2 receptor partial agonist with preferential binding to D3 receptors, is being developed for the treatment of schizophrenia and bipolar mania. This Phase II trial evaluated the efficacy, safety, and tolerability of cariprazine versus placebo in the treatment of acute manic or mixed episodes associated with bipolar I disorder. METHODS: This was a multinational, randomized, double-blind, placebo-controlled, flexible-dose study of cariprazine 3-12 mg/day in patients with acute manic or mixed episodes associated with bipolar I disorder. Following washout, patients received three weeks of double-blind treatment. The primary and secondary efficacy parameters were change from baseline to Week 3 in Young Mania Rating Scale (YMRS) and Clinical Global Impressions-Severity (CGI-S) scores, respectively. Post-hoc analysis evaluated changes on YMRS single items. RESULTS: In each group, 118 patients received double-blind treatment; 61.9% of placebo and 63.6% of cariprazine patients completed the study. The overall mean daily dose of cariprazine was 8.8 mg/day. At Week 3, cariprazine significantly reduced YMRS and CGI-S scores versus placebo, with least square mean differences of -6.1 (p < 0.001) and -0.6 (p < 0.001), respectively. On each YMRS item, change from baseline to Week 3 was significantly greater for cariprazine versus placebo (all, p < 0.05). A significantly greater percentage of cariprazine patients than placebo patients met YMRS response (48% versus 25%; p < 0.001) and remission (42% versus 23%; p = 0.002) criteria at Week 3. Adverse events (AEs) led to discontinuation of 12 (10%) placebo and 17 (14%) cariprazine patients. The most common AEs (> 10% for cariprazine) were extrapyramidal disorder, headache, akathisia, constipation, nausea, and dyspepsia. Changes in metabolic parameters were similar between groups, with the exception of fasting glucose; increases in glucose were significantly greater for cariprazine versus placebo (p < 0.05). Based on Barnes Akathisia Rating Scale and Simpson-Angus Scale scores, more cariprazine than placebo patients experienced treatment-emergent akathisia (cariprazine: 22%; placebo: 6%) or extrapyramidal symptoms (parkinsonism) (cariprazine: 16%; placebo: 1%). CONCLUSION: Cariprazine demonstrated superior efficacy versus placebo and was generally well tolerated in patients experiencing acute manic or mixed episodes associated with bipolar I disorder.

Brain uptake and distribution of the dopamine D3 /D2 receptor partial agonist [11 C]cariprazine: an in vivo positron emission tomography study in nonhuman primates.

Cariprazine is a dopamine D(3)/D(2) receptor partial agonist antipsychotic candidate, which binds with high affinity to dopamine D(3) and D(2) receptors (with ∼10-fold higher in vitro affinity to D(3) vs. D(2) receptors) and with moderate affinity to 5-HT(1A) receptors. The main objective of the present molecular imaging investigation was to evaluate the uptake and reversible binding of 11-C labeled cariprazine in the nonhuman primate brain, in relation to the known distributions of dopamine D(2) and D(3) receptors. We examined the brains of two cynomolgus monkeys at baseline condition as well as during a pharmacological blocking condition, using unlabeled cariprazine or raclopride as blockers before injection of [(11) C]cariprazine. Of the total injected radioactivity, ∼7% entered the brain and ∼3-4% remained in the brain after 90 min, indicating good blood brain barrier penetration and slow washout. It was possible to block cariprazine binding with unlabeled cariprazine and raclopride indicating that [(11) C]cariprazine binds to dopamine D(3)/D(2) receptors. Nondisplaceable binding potential (BPND) measurements, using a simplified reference tissue model and cerebellum as the reference region, yielded values of ∼1.5 and 0.3 in the striatum and thalamus, respectively. Striatum BPND values were reduced by 80 and 85% following pretreatment with 0.1 mg/kg IV injection of unlabeled cariprazine and 1 mg/kg IV injection of unlabeled raclopride, respectively. The data confirm that cariprazine, a novel antipsychotic drug candidate, enters the nonhuman primate brain readily and binds to dopamine D(3)/D(2) receptors. Furthermore, in PET imaging [(11) C]cariprazine can effectively visualize dopamine D(3)/D(2) receptors in the nonhuman primate brain.

Discovery of cariprazine (RGH-188): a novel antipsychotic acting on dopamine D3/D2 receptors.

Medicinal chemistry optimization of an impurity isolated during the scale-up synthesis of a pyridylsulfonamide type dopamine D(3)/D(2) compound (1) led to a series of new piperazine derivatives having affinity to both dopamine D(3) and D(2) receptors. Several members of this group showed excellent pharmacokinetic and pharmacodynamic properties as demonstrated by outstanding activities in different antipsychotic tests. The most promising representative, 2m (cariprazine) had good absorption, excellent brain penetration and advantageous safety profile. Based on its successful clinical development we are looking forward to the NDA filing of cariprazine in 2012.

Potential Mechanisms for Why Not All Antipsychotics Are Able to Occupy Dopamine D3 Receptors in the Brain in vivo.

Dysfunctions of the dopaminergic system are believed to play a major role in the core symptoms of schizophrenia such as positive, negative, and cognitive symptoms. The first line of treatment of schizophrenia are antipsychotics, a class of medications that targets several neurotransmitter receptors in the brain, including dopaminergic, serotonergic, adrenergic and/or muscarinic receptors, depending on the given agent. Although the currently used antipsychotics display in vitro activity at several receptors, majority of them share the common property of having high/moderate in vitro affinity for dopamine D2 receptors (D2Rs) and D3 receptors (D3Rs). In terms of mode of action, these antipsychotics are either antagonist or partial agonist at the above-mentioned receptors. Although D2Rs and D3Rs possess high degree of homology in their molecular structure, have common signaling pathways and similar in vitro pharmacology, they have different in vivo pharmacology and therefore behavioral roles. The aim of this review, with summarizing preclinical and clinical evidence is to demonstrate that while currently used antipsychotics display substantial in vitro affinity for both D3Rs and D2Rs, only very few can significantly occupy D3Rs in vivo. The relative importance of the level of endogenous extracellular dopamine in the brain and the degree of in vitro D3Rs receptor affinity and selectivity as determinant factors for in vivo D3Rs occupancy by antipsychotics, are also discussed.

What Is the Minimum Clinically Important Change in Negative Symptoms of Schizophrenia? PANSS Based Post-hoc Analyses of a Phase III Clinical Trial.

Introduction: Minimum clinically important difference (MCID) is a measure that defines the minimum amount of change in an objective score of a clinical test that must be reached for that change to be clinically noticeable. We aimed to find the MCID for patients with predominantly negative symptoms of schizophrenia at its earliest occurrence. Methods: Data of a 26-week long, double-blind study with 454 patients [Positive and Negative Symptom Scale Negative Factor Score (PANSS-FSNS) ≥24, Positive and Negative Symptom Scale Positive Factor Score (PANSS-FSPS) ≤ 19] treated with cariprazine 4.5 mg/d or risperidone 4 mg/d were analyzed. The Clinical Global Impression-Improvement scale was used to quantify minimum improvement (CGI-I = 3) and no clinical change (CGI-I = 4) on the PANSS-FSNS, and the MCID was estimated with the following methods: as the mean PANSS-FSNS changes corresponding to the first instance of minimal improvement across all visits (MCID1); as the difference between the PANSS-FSNS change associated with the first instance and the PANSS-FSNS changes associated with the last recorded clinically unchanged status across all visits (MCID2); with the effect size approach (MCID3); as the Youden Index based cut-off value between no clinical change and minimal improvement (MCID4); as the relative likelihood of minimal improvement (MCID5). Results: The MCID1 and MCID2 resulted in, respectively, a 3.8-point (18.5%) and a 1.5-point (7.3%) decrease from baseline severity on the PANSS-FSNS. Greater values were required for the MCID at later evaluation times. The cut-off between minimum improvement and no clinical change defined by the Youden Index was a-3-point (15%) change in the PANSS-FSNS. The effect size approach indicated the 1.5-point difference between minimally improved and unchanged patients to be a medium effect (ES = 0.6). Conclusion: Applying different methods led to different results, ranging between 7.3 and 18.5% improvement from the baseline for the MCID at its earliest occurrence in patients with predominantly negative symptoms of schizophrenia.

Cariprazine, A Broad-Spectrum Antipsychotic for the Treatment of Schizophrenia: Pharmacology, Efficacy, and Safety.

Schizophrenia is characterized by positive, negative, cognitive, and affective symptoms. Antipsychotic medications, which work by blocking the dopamine D2 receptor, are the foundation of pharmacotherapy for schizophrenia to control positive symptoms. Cariprazine is a dopamine D3 receptor-preferring D3/D2 partial agonist antipsychotic that is approved for the treatment of schizophrenia (USA and European Union [EU]) and manic and depressive episodes associated with bipolar I disorder (USA). Partial agonist agents have a lower intrinsic activity at receptors than full agonists, so they act as either functional agonists or functional antagonists depending on the surrounding neurotransmitter environment. Beyond efficacy against positive symptoms, the unique D3-preferring partial agonist pharmacology of cariprazine suggests potential advantages against negative symptoms, and cognitive and functional impairment, which are challenging to treat. The efficacy and safety of cariprazine in adult patients with schizophrenia have been demonstrated in four short-term randomized, double-blind, placebo-controlled clinical trials, two long-term open-label studies, one relapse prevention study, and one prospective negative symptom study versus the active comparator risperidone. Additional post hoc investigations have supported efficacy across individual symptoms and domains in schizophrenia, as well as in diverse areas of interest including cognition, functioning, negative symptoms, hostility, and global well-being. This comprehensive review of cariprazine summarizes its pharmacologic profile, clinical trial evidence, and post hoc investigations. Collective evidence suggests that the pharmacology of cariprazine may offer broad-spectrum efficacy advantages for patients with schizophrenia, including effects against difficult-to-treat negative and cognitive symptoms, as well as functional improvements. Cariprazine was generally safe and well tolerated in patients with short- and long-term exposure and no new safety concerns were associated with longer-duration treatment.Trial registration ClinicalTrials.gov identifiers, NCT00404573, NCT00694707, NCT01104766, NCT01104779, NCT01412060, NCT00839852, NCT01104792.

Safety and Tolerability of Cariprazine in Patients with Schizophrenia: A Pooled Analysis of Eight Phase II/III Studies.

BACKGROUND: Long-term treatment with antipsychotic agents is indicated for patients with schizophrenia, but treatment is associated with adverse events (AEs) that contribute to medication discontinuation and nonadherence. Understanding drug safety profiles is critical to avoid unwanted side effects. Cariprazine is a potent dopamine D3/D2 receptor partial agonist that is approved for the treatment of adults with schizophrenia (EU, US) and acute manic/mixed and depressive episodes associated with bipolar I disorder (US). METHODS: Post hoc analyses were conducted to characterize the safety profile of cariprazine within the recommended 1.5-6 mg/d dose range for schizophrenia; data from 8 short- or long-term clinical trials were analyzed. RESULTS: In the pooled cariprazine-treated safety population (n=2048), the rate of study completion was 52.8%, with withdrawal of consent, insufficient response, and AEs the most common reasons for premature discontinuation. The most commonly reported AEs (>10%) in the overall cariprazine-treatment group were akathisia (14.6%), insomnia (14.0%), and headache (12.1%); most AEs were considered mild (71.0%) or moderate (26.5%). Most akathisia was mild/moderate (97.5%) and >93% of patients remained on treatment; akathisia events were managed by rescue medications (56.3%) or dose reduction (18.3%). The metabolic profile of cariprazine was neutral in patients with short- and long-term exposure; mean weight gain was 1 kg for overall cariprazine, with an AE of weight increased reported for 5.1%. Other AEs of special interest that occurred at >3% for overall cariprazine were extrapyramidal disorder (7.0%), sedation (3.7%), and somnolence (3.1%); prolactin elevation, cognition impairment, sexual dysfunction, suicidality, and QT prolongation occurred at ≤1%. CONCLUSION: Akathisia, the most common cariprazine-related AE, was mild/moderate and resulted in few study discontinuations; symptoms were well managed and most patients remained on treatment. Results of this analysis indicated that cariprazine in the recommended dose range was safe and generally well tolerated in patients with schizophrenia. TRIAL REGISTRATION: Studies registered with ClinicalTrials.gov (NCT00404573, NCT01104779, NCT00694707, NCT01104766, NCT01104792, NCT00839852, and NCT01412060) and EudraCT (2012-005485-36).

Neuronal Dopamine D3 Receptors: Translational Implications for Preclinical Research and CNS Disorders.

Dopamine (DA), as one of the major neurotransmitters in the central nervous system (CNS) and periphery, exerts its actions through five types of receptors which belong to two major subfamilies such as D1-like (i.e., D1 and D5 receptors) and D2-like (i.e., D2, D3 and D4) receptors. Dopamine D3 receptor (D3R) was cloned 30 years ago, and its distribution in the CNS and in the periphery, molecular structure, cellular signaling mechanisms have been largely explored. Involvement of D3Rs has been recognized in several CNS functions such as movement control, cognition, learning, reward, emotional regulation and social behavior. D3Rs have become a promising target of drug research and great efforts have been made to obtain high affinity ligands (selective agonists, partial agonists and antagonists) in order to elucidate D3R functions. There has been a strong drive behind the efforts to find drug-like compounds with high affinity and selectivity and various functionality for D3Rs in the hope that they would have potential treatment options in CNS diseases such as schizophrenia, drug abuse, Parkinson's disease, depression, and restless leg syndrome. In this review, we provide an overview and update of the major aspects of research related to D3Rs: distribution in the CNS and periphery, signaling and molecular properties, the status of ligands available for D3R research (agonists, antagonists and partial agonists), behavioral functions of D3Rs, the role in neural networks, and we provide a summary on how the D3R-related drug research has been translated to human therapy.

Disentangling the symptoms of schizophrenia: Network analysis in acute phase patients and in patients with predominant negative symptoms.

BACKGROUND: The Positive and Negative Syndrome Scale (PANSS) is widely used in schizophrenia and has been divided into distinct factors (5-factor models) and subfactors. Network analyses are newer in psychiatry and can help to better understand the relationships and interactions between the symptoms of a psychiatric disorder. The aim of this study was threefold: (a) to evaluate connections between schizophrenia symptoms in two populations of patients (patients in the acutely exacerbated phase of schizophrenia and patients with predominant negative symptoms [PNS]), (b) to test whether network analyses support the Mohr 5 factor model of the PANSS and the Kahn 2 factor model of negative symptoms, and finally (c) to identify the most central symptoms in the two populations. METHODS: Using pooled baseline data from four cariprazine clinical trials in patients with acute exacerbation of schizophrenia (n = 2193) and the cariprazine-risperidone study in patients with PNS (n = 460), separate network analyses were performed. Network structures were estimated for all 30 items of the PANSS. RESULTS: While negative symptoms in patients with an acute exacerbation of schizophrenia are correlated with other PANSS symptoms, these negative symptoms are not correlated with other PANSS symptoms in patients with PNS. The Mohr factors were partially reflected in the network analyses. The two most central symptoms (largest node strength) were delusions and uncooperativeness in acute phase patients and hostility and delusions in patients with PNS. CONCLUSIONS: This network analysis suggests that symptoms of schizophrenia are differently structured in acute and PNS patients. While in the former, negative symptoms are mainly secondary, in patients with PNS, they are mainly primary. Further, primary negative symptoms are better conceptualized as distinct negative symptom dimensions of the PANSS.

Cariprazine (RGH-188), a dopamine D(3) receptor-preferring, D(3)/D(2) dopamine receptor antagonist-partial agonist antipsychotic candidate: in vitro and neurochemical profile.

Cariprazine {RGH-188; trans-N-[4-[2-[4-(2,3-dichlorophenyl)piperazin-1-yl]ethyl]cyclohexyl]-N',N'-dimethylurea hydrochloride}, a novel candidate antipsychotic, demonstrated approximately 10-fold higher affinity for human D(3) versus human D(2L) and human D(2S) receptors (pKi 10.07, 9.16, and 9.31, respectively). It displayed high affinity at human serotonin (5-HT) type 2B receptors (pK(i) 9.24) with pure antagonism. Cariprazine had lower affinity at human and rat hippocampal 5-HT(1A) receptors (pK(i) 8.59 and 8.34, respectively) and demonstrated low intrinsic efficacy. Cariprazine displayed low affinity at human 5-HT(2A) receptors (pK(i) 7.73). Moderate or low affinity for histamine H(1) and 5-HT(2C) receptors (pK(i) 7.63 and 6.87, respectively) suggest cariprazine's reduced propensity for adverse events related to these receptors. Cariprazine demonstrated different functional profiles at dopamine receptors depending on the assay system. It displayed D(2) and D(3) antagonism in [(35)S]GTPgammaS binding assays, but stimulated inositol phosphate (IP) production (pEC(50) 8.50, E(max) 30%) and antagonized (+/-)-quinpirole-induced IP accumulation (pK(b) 9.22) in murine cells expressing human D(2L) receptors. It had partial agonist activity (pEC(50) 8.58, E(max) 71%) by inhibiting cAMP accumulation in Chinese hamster ovary cells expressing human D(3) receptors and potently antagonized R(+)-2-dipropylamino-7-hydroxy-1,2,3,4-tetrahydronaphtalene HBr (7-OH-DPAT)-induced suppression of cAMP formation (pK(b) 9.57). In these functional assays, cariprazine showed similar (D(2)) or higher (D(3)) antagonist-partial agonist affinity and greater (3- to 10-fold) D(3) versus D(2) selectivity compared with aripiprazole. In in vivo turnover and biosynthesis experiments, cariprazine demonstrated D(2)-related partial agonist and antagonist properties, depending on actual dopaminergic tone. The antagonist-partial agonist properties of cariprazine at D(3) and D(2) receptors, with very high and preferential affinity to D(3) receptors, make it a candidate antipsychotic with a unique pharmacological profile among known antipsychotics.

Cariprazine Safety in Adolescents and the Elderly: Analyses of Clinical Study Data.

Schizophrenia is a life-long mental disorder, affecting young adolescents to elderly patients. Antipsychotic treatment is indicated for all patients with schizophrenia, including the very young and old as well. Developmental issues in the young and decline in organ functioning in the elderly could influence reactions to the drug, and require different dosing regimens. The aim of the present article was to examine the safety profile and dosing requirements in adolescent (13 to less than 18) and elderly (65 and above) patients treated with cariprazine. Data from two clinical studies (one pharmacokinetic pediatric study and one phase III clinical trial) on 49 adolescent patients and 17 elderly patients (65 years of age or above) treated with cariprazine was examined. Safety measures included assessment of adverse events (AEs), clinical laboratory values, physical examinations, extrapyramidal symptom (EPS)-, depression-, and suicidality rating scales. Safety parameters were summarized using descriptive statistics. Results indicate that cariprazine was generally safe and well tolerated. Adverse events in the marginal age populations were comparable to the adult population, except for less insomnia in the young and no reports of akathisia in the elderly. Laboratory parameters, vital sign values and EEG parameters were comparable to previously published data in the adult population. In conclusion, cariprazine in the approved adult dose-range of 1.5-6 mg might be a safe treatment option also in adolescent and elderly patients with schizophrenia. Further studies are need to verify these preliminary findings.

Linking PANSS negative symptom scores with the Clinical Global Impressions Scale: understanding negative symptom scores in schizophrenia.

Understanding how rating scale improvement corresponds to a clinical impression in patients with negative symptoms of schizophrenia may help define the clinical relevance of change in this patient population. We conducted post hoc equipercentile linking analyses of Positive and Negative Syndrome Scale (PANSS) outcomes (e.g., PANSS-Factor Score for Negative Symptoms [FSNS]) with Clinical Global Impressions-Improvement (CGI-I) and -Severity (CGI-S) ratings on data from patients treated with cariprazine (n = 227) or risperidone (n = 229) in a clinical study evaluating negative symptoms in schizophrenia. Patients were prospectively selected for persistent, predominant negative symptoms of schizophrenia (PNS), and minimal positive/depressive/extrapyramidal symptoms. Linking results demonstrated that greater improvement on PANSS-derived measures corresponded to clinical impressions of greater improvement, as measured by the CGI-I, and less severe disease states, as measured by the CGI-S. For example, CGI-S scores of 1 (normal), 2, 3, 4, 5, and 6 (severely ill) corresponded to PANSS-FSNS scores of 7, 13, 19, 24, 29, and 35, respectively. Likewise, CGI-I scores of minimally improved, much improved, and very much improved corresponded to a change from baseline in PANSS-FSNS scores of -27%, -49%, and -100%, respectively. These are important findings for the interpretation of the results of trials in patients with persistent negative symptoms.