Aripiprazole once-monthly long-acting injectable for the treatment of schizophrenia

Seventy Years of Antipsychotic Development: A Critical Review

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

Adherence, Tolerability and Effective Doses of Aripiprazole Once-monthly in the Long-term Treatment of Patients with Severe Schizophrenia

BACKGROUND

The evaluation of long-term effectiveness and tolerability of Aripiprazole Once-monthly (AOM) is yet scarce, and severely ill patients have not been specifically studied.

OBJECTIVE

The aim of the study was to explore the long-term adherence, effectiveness and tolerability of AOM in the treatment of patients with severe (Clinical Global Impression-Severity, CGI-S ≥ 5) schizophrenia, and whether high-dose therapy may benefit patients inadequately controlled on standard doses.

METHOD

Six-year mirror-image study, with 36-month prospective follow-up, was conducted on patients with severe schizophrenia who underwent treatment with AOM (n = 60). Assessment included the CGI-S, the WHO Disability Assessment Schedule (WHO-DAS), the Medication Adherence Report Scale (MARS), laboratory tests, and weight and adverse effects reported. Reasons for treatment discontinuation, hospital admissions and psychiatric medications in the previous three years and during the follow-up were recorded.

RESULTS

The average dose was found to be 780 (120) mg/28 days. Tolerability was good, with few side effects or biological parameters alterations reported. There were three discharges due to adverse effects, two due to lack of effectiveness and one treatment abandoning. Weight and prolactin levels were found to be decreased. CGI-S and WHO-DAS decreased (p < 0.001), and MARS increased (p < 0.001). There were less treatment abandoning, hospital admissions (p < 0.0001) and concomitant medication (p<0.01) than during the previous 36 months.

CONCLUSION

Treatment adherence and tolerability of AOM were found to be remarkable, even in those patients on high doses. AOM showed effectiveness in patients with severe schizophrenia, who recorded less hospitalizations and clinical severity and disability, although a considerable percentage of them needed higher doses than labeled.

Schizophrenia; A Review on Promising Drug Delivery Systems

Background:

Schizophrenia belongs to mental illnesses affecting 1% of the worldwide population. Its therapy is still unmet; thus, researchers aimed to develop new pharmacological molecules which can improve its management.

Methods:

Moreover, the current typical and atypical antipsychotics should be formulated in more efficacious systems that can deliver the drug in the brain with as few side effects as possible. Further, the development of long-acting efficient drug delivery systems could be significant in minimizing frequent dosing which is nonpreferred to schizophrenics.

Results:

Herein, authors focused on current developments of antipsychotic medications used in schizophrenia management. Various studies, which include the use of first and second-generation antipsychotics, were analyzed according to their efficacy. In fact, in this review, oral, injectable, transdermal and intranasal formulations entrapped antipsychotics are presented to be valuable guidance for scientists to formulate more effective drug delivery systems for schizophrenic patients.

Conclusions:

This review aimed to assist researchers working on schizophrenia management by summarizing current medications and newly synthesized drug delivery systems recently found in the literature.

Acceptance of the Deltoid Muscle Injection of Aripiprazole Long-acting Injectable in the Patients with Schizophrenia

Objective

To improve poor medication adherence in schizophrenic patients, long-acting injectable (LAI) antipsychotics are used. However, it has not yet become common in Japan. Recently, aripiprazole LAI was approved for alternative injection into the deltoid muscle in addition to the gluteal muscle. The acceptance for the proposal to switch from gluteal to deltoid injections of aripiprazole LAI was investigated.

Methods

The subjects were 32 outpatients with schizophrenia who had continuously received aripiprazole LAI administration into the gluteal muscle for ≥ 6 months. In the patients who had continued deltoid injection for 3 months after switching, the changes in the pain and shame in comparison with gluteal injections were evaluated.

Results

Switching to the deltoid injection was chosen by 17 out of 32 patients. Three months later, 9 patients were still receiving deltoid injections with highly rated satisfaction. The main reasons for switching to deltoid injections included the pain and shame associated with gluteal injections. The main reason for returning to the gluteal injection was the pain experienced from the injection in the deltoid.

Conclusion

The option to select the injected area was based on the amount of pain in the deltoid and gluteal sites, leading to the widespread use of aripiprazole LAI.

Impact of age and CYP2D6 genetics on exposure of aripiprazole and dehydroaripiprazole in patients using long-acting injectable versus oral formulation: relevance of poor and intermediate metabolizer status

PURPOSE

Tailoring medication dosing for the individual patient is complex, and many factors can influence drug exposure. We investigated the effect of age and CYP2D6 genotype on aripiprazole and dehydroaripiprazole exposure in patients using long-acting injectable (LAI) or oral aripiprazole.

METHODS

Matched data on serum concentration of aripiprazole and CYP2D6 genotype of patients using oral or LAI aripiprazole were included retrospectively from a therapeutic drug monitoring service. The patients were divided into the following CYP2D6 genotype-defined categories: poor metabolizers (PMs), intermediate metabolizers (IMs), normal metabolizers (NMs), and ultrarapid metabolizers (UMs). Linear mixed model analyses were used to evaluate the impact of CYP2D6 genotype on dose-adjusted serum concentrations of the active moiety of aripiprazole+dehydroaripiprazole in relation to age and formulation.

RESULTS

We identified 635 patients (mean age = 40.1 years, 9.4% ≥ 65 years, 53.7% females) using LAI (n = 166) or oral formulation (n = 469). The genotype-predicted CYP2D6 phenotype subgroups were 2.4% UMs, 82.0% NMs, 8.0% IMs, and 7.2% PMs. Age did not significantly affect exposure of the active moiety of aripiprazole+dehydroaripiprazole in the LAI (p = 0.071) or oral (p = 0.14) subgroups. Compared with CYP2D6 NMs, PMs and IMs had significantly increased exposure of the active moiety of aripiprazole+dehydroaripiprazole in the LAI (1.7-fold higher, p < 0.001, and 1.5-fold higher, p < 0.001) and oral (1.7-fold higher, p < 0.001, and 1.6-fold higher, p < 0.001) subgroups.

CONCLUSIONS

In conclusion, doses should be adjusted according to CYP2D6 genotype when initiating treatment with aripiprazole LAI or tablets, while advanced age do not affect the exposure of the active moiety of aripiprazole treatment regardless of formulation.

Real-life assessment of aripiprazole monthly (Abilify Maintena) in schizophrenia: a Canadian naturalistic non-interventional prospective cohort study

BACKGROUND

With previously established efficacy of aripiprazole once-monthly injectable formulation (AOM) in pre-registration randomized controlled trials, the current study was designed to evaluate its effectiveness in patients treated for schizophrenia in regular clinical settings in Canada.

METHODS

Following their clinicians' decision to prescribe AOM, 193 patients with a diagnosis of schizophrenia, were recruited from 17 Canadian community or hospital-based settings. The primary outcome of global functioning was assessed with the Global Assessment of Functioning Scale (GAF) at 3-month intervals for 1 year. Secondary outcomes (social and occupational functioning and illness severity) and adverse drug reactions (ADR) were also assessed.

RESULTS

A majority of the 169 evaluable patients were within the first 5 years of diagnosis (early phase). A linear mixed model analysis showed a significant main effect of time (Type III test p < 0.001) after adjusting for baseline GAF score, with a change in mean GAF scores from 49 at baseline to 61 at 12 months. No differences between early vs late phase were observed. Results on secondary outcome measures of function (Social and Occupational Functioning Scale) and illness severity (Clinical Global Impression-Severity Scale and Brief Psychiatric Rating Scale) were similar. Serious ADRs were observed in 29 (14.6%) patients and akathisia in 18 (9.1%) patients. At month-12, significant (≥7%) weight gain was observed in 25.7% (n = 27/105) of patients.

CONCLUSIONS

Treatment with AOM is effective in improving symptoms and functioning in schizophrenia patients treated in regular clinical settings. Akathisia was infrequent while one quarter of patients gained clinically significant weight.

TRIAL REGISTRATION

Unique identifier: NCT02131415 . First posted: 06 May 2014.

Relationship between the timing of relapse and plasma drug levels following discontinuation of cariprazine treatment in patients with schizophrenia: indirect comparison with other second-generation antipsychotics after treatment discontinuation

OBJECTIVE

To explore the timing of relapse following drug discontinuation and its relationship to estimated plasma levels and elimination half-life by comparing data from a randomized, placebo-controlled discontinuation study of cariprazine with those from similarly designed and conducted randomized control trials of other oral atypical antipsychotics (AAPs).

METHODS

Data from a long-term, randomized, double-blind, placebo-controlled relapse prevention study in participants with schizophrenia (NCT01412060) were analyzed. Similarly designed, published studies of other AAPs were used for comparison. Time to drug-placebo relapse separation and relapse rates were estimated from Kaplan-Meier curves and evaluated descriptively. Separation was defined as a sustained difference of ≥5% incidence of relapse between the AAP and placebo curves.

RESULTS

The Kaplan-Meier curve for cariprazine showed a time to drug-placebo relapse separation at 6-7 weeks after randomization, compared to the Kaplan-Meier curves for the other AAPs, which showed earlier separation at 1-4 weeks. The placebo relapse rates at 4 weeks after randomization were 5% for cariprazine and 8-34% for other AAPs. Geometric mean values of model-predicted plasma concentrations for total active cariprazine moieties (sum of cariprazine, desmethyl-cariprazine, and didesmethyl-cariprazine) were 20.0 and 6.1 nM at 2 and 4 weeks after discontinuation, respectively. Elimination half-lives of other AAPs and their active metabolites (<4 days) suggest that plasma concentrations would be low or negligible at 2-4 weeks after last dose.

CONCLUSION

Discontinuation of cariprazine treatment appeared to be associated with a delayed incidence of relapse compared with other AAPs, which may be due to the longer half-life of cariprazine and its active metabolites.

Effectiveness of aripiprazole once-monthly in schizophrenia patients pretreated with oral aripiprazole: a 6-month, real-life non-interventional study

BACKGROUND

In this study, the treatment of schizophrenia patients with aripiprazole once-monthly (AOM) was evaluated under real-life conditions in a naturalistic setting.

METHODS

This multicenter, prospective, non-interventional study included 242 patients (age = 43.1 ± 15.1 years, 55.0% male) who were monitored during 6 months of AOM treatment. Endpoints included measurements of psychopathology (Brief Psychiatric Rating Scale, BPRS) and severity of illness scales (Clinical Global Impressions-Severity, CGI-S, and -Improvement, CGI-I). Furthermore, treatment-related adverse events (TRAEs) were recorded.

RESULTS

At baseline, the mean BPRS total score was 54.1 ± 15.6, the mean CGI-S was 4.8 ± 0.8 and the most frequent illness category was 'markedly ill' (41.7%). Patients had been pretreated with oral aripiprazole for a mean duration of 9.7 months (SD: 22.3) and 87.9% were deemed by their clinician as "clinically stable" and for a mean of 5.9 months. The difference in global BPRS after 6 months was - 13.8 (SD: 16.0; 95% CI: [- 15.9; - 11.7]; p < 0.001). The proportion of patients with high CGI-S scores decreased and the proportion of patients with low scores increased significantly (p < 0.001, respectively). BPRS scores improved numerically especially well in younger patients ≤35 years, CGI-S scores decreased significantly more in this population. TRAEs were rare, with low incidences of extrapyramidal symptoms (2.9%) or weight increase (0.4%).

CONCLUSIONS

Treatment with AOM showed satisfying effectiveness in outpatients with further improvement of psychopathology after oral aripiprazole treatment for a considerable duration and even after having achieved clinically judged "stability". Our findings indicate a robust therapeutic effect of AOM and substantiate previous results from randomized controlled trials under real-world routine conditions.

Paliperidone palmitate once-monthly maintains improvement in functioning domains of the Personal and Social Performance scale compared with placebo in subjects with schizoaffective disorder

OBJECTIVE

Evaluate the effect of paliperidone palmitate once-monthly (PP1M) injectable on the specific functioning domains of the Personal and Social Performance (PSP) scale in patients with schizoaffective disorder (SCA) participating in a long-term study.

METHODS

This study (NCT01193153) included both in- and outpatient subjects with SCA experiencing an acute exacerbation of psychotic and mood symptoms. Subjects were treated with PP1M either as monotherapy or in combination with antidepressants or mood stabilizers during a 25-week open-label (OL) phase. Stabilized subjects were randomly assigned 1:1 (PP1M or placebo) into a 15-month double-blind (DB) relapse-prevention period. Functioning of the randomized subjects during OL and DB phases was evaluated using the PSP scale (four domains: socially useful activities, personal/social relationships, self-care, and disturbing/aggressive behaviors). Three statistical approaches were utilized to analyze PSP scores to assess robustness and consistency of findings. No adjustments were made for multiplicity.

RESULTS

334 of 667 enrolled subjects were stabilized with PP1M, randomly assigned to PP1M (n=164) or placebo (n=170) in the DB phase, and included in this analysis. Improvements in all PSP domain scores were observed during the OL phase and were maintained during the DB phase with PP1M, but decreased with placebo. Differences compared to placebo were significant in all four PSP domains during the DB phase (P≤0.008).

CONCLUSION

The analysis in this study showed that PP1M improves functioning, as measured by the four PSP domain scores, in symptomatic subjects with SCA. Functioning was maintained compared with placebo.

Aripiprazole, A Drug that Displays Partial Agonism and Functional Selectivity

BACKGROUND

The treatment of schizophrenia is challenging due to the wide range of symptoms (positive, negative, cognitive) associated with the disease. Typical antipsychotics that antagonize D2 receptors are effective in treating positive symptoms, but extrapyramidal side-effects (EPS) are a common occurrence. Atypical antipsychotics targeting 5-HT2A and D2 receptors are more effective at treating cognitive and negative symptoms compared to typical antipsychotics, but these drugs also result in side-effects such as metabolic syndromes.

OBJECTIVE

To identify evidence in the literature that elucidates the pharmacological profile of aripiprazole.s.

METHODS

We searched PubMed for peer reviewed articles on aripiprazole and its clinical efficacy, side-effects, pharmacology, and effects in animal models of schizophrenia symptoms.

RESULTS

Aripiprazole is a newer atypical antipsychotic that displays a unique pharmacological profile, including partial D2 agonism and functionally selective properties. Aripiprazole is effective at treating the positive symptoms of schizophrenia and has the potential to treat negative and cognitive symptoms at least as well as other atypical antipsychotics. The drug has a favorable side-effect profile and has a low propensity to result in EPS or metabolic syndromes. Animal models of schizophrenia have been used to determine the efficacy of aripiprazole in symptom management. In these instances, aripiprazole resulted in the reversal of deficits in extinction, pre-pulse inhibition, and social withdrawal. Because aripiprazole requires a greater than 90% occupancy rate at D2 receptors to be clinically active and does not produce EPS, this suggests a functionally selective effect on intracellular signaling pathways.

CONCLUSION

A combination of factors such as dopamine system stabilization via partial agonism, functional selectivity at D2 receptors, and serotonin-dopamine system interaction may contribute to the ability of aripiprazole to successfully manage schizophrenia symptoms. This review examines these mechanisms of action to further clarify the pharmacological actions of aripiprazole.

Morphological and Crystalline Transitions in Monohydrous and Anhydrous Aripiprazole for a Long-Acting Injectable Suspension

Many formulation and manufacturing processes can lead to morphological and crystalline transitions in many polycrystalline drugs, changing the properties of active pharmaceutical ingredients (APIs) such as solubility and physical stability which influence their therapeutic effects and safety and so limit their usefulness. Here, we report significant changes in crystal forms and morphology, including the shape and size of particles during the manufacture of off-white aripiprazole (APZ) dry powders used for long-acting and injectable suspensions. With the optimal top-down approach, powders were prepared by recrystallizing uniform monohydrous APZ (MA) and polycrystalline anhydrous APZ (AA) form III, characterized by thermal analysis, PXRD, and FT-IR. However, powders involving MA (MAP) with a lower mean size (2.126 μm), narrower distribution (span = 1.90), and higher stability compared with AA dry powders (AAP) were found to exhibit dehydration behavior and morphological changes after completion of the preparation processes based on the results of thermal analysis. In the case of APZ powders, we wished to obtain more information to guide in the industrial production and experimental design of suspensions in the future.