Background
Clinical studies performed during the development of new antipsychotics (efficacy studies) often involve many eligibility criteria for the selection of candidates and tend to be confined to small patient groups. Furthermore, in efficacy studies, the magnitude of changes in psychiatric symptom score during short periods of time and adverse reactions are evaluated independently. Because of these features of study design, it is difficult to generalize the results of efficacy studies readily into rationales for the selection of antipsychotics for schizophrenia in routine clinical practice [
1]. In contrast, the goals of long-term treatment for schizophrenia encompass improvement in the social activity and in the Quality of Life (QOL) of patients. In this sense, effectiveness studies that can yield new findings regarding the long-term outcome of treatments have become increasingly important. In Western countries, evidence partially supporting the selection of antipsychotics has been accumulating from studies that compared the long-term outcome primarily of olanzapine and risperidone, as well as other second-generation antipsychotics (SGAs) and first-generation antipsychotics (FGAs) [
2,
3]. In Japan, however, no large-scale effectiveness study has been carried out. Moreover, sufficient data on the long-term outcome of treatment with aripiprazole, blonanserin, and paliperidone, that were marketed relatively recently, are unavailable in Japan and in Western countries. Thus, it is desirable to obtain evidence for the selection of these 3 drugs in Japan.
Under such circumstances, we planned a long-term (2-year) dosing study to evaluate the effectiveness of aripiprazole, blonanserin, and paliperidone on discontinuation rate, remission rate and improvement of social activity in patients treated with these drugs (Japan Useful Medication Program for schizophrenia: JUMPs).
Discussion
Efficacy studies on antipsychotics can be characterized by the enrollment of small patient groups, short duration, separate evaluation of the magnitude of change in psychiatric symptom scores and adverse reactions. The results of efficacy studies exhibiting these characteristics are not always consistent with the usefulness of antipsychotics experienced by physicians in clinical practice. For this reason, there is a growing awareness of the importance of the long-term assessment using effectiveness studies: to this effect, numerous large-scale studies, such as the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE), have been carried out in Western countries [
2,
3,
7‐
9]. In these studies, comparisons were made among SGAs or between SGAs and FGAs, yielding various findings that are useful for the selection of drugs (primarily risperidone, olanzapine, and quetiapine) based on long-term outcome. In the case of drugs such as aripiprazole, blonanserin, and paliperidone, which were marketed relatively recently in Japan, sufficient long-term outcome data have not been collected, even in Western countries.
Aripiprazole exhibits not only serotonin 5-HT2A receptor blocking activity, but also dopamine D2 and serotonin 5-HT1A receptor partial agonist activity, which is an activity that any other antipsychotics do not possess. Aripiprazole has a low adrenaline α1 and histamine H1 receptor blocking activity and no muscarinic M1 receptor blocking activity. It is less likely to exert sedative effects, to cause weight gain, or to affect the metabolic system [
10,
11]. Blonanserin has dopamine D2 and serotonin 5-HT2A receptor blocking activity but, unlike other SGAs, has higher affinity for dopamine D2 receptor than for serotonin 5-HT2A receptor. Therefore, it exhibits characteristics of dopamine-serotonin antagonists. Much is expected of this drug regarding its effects on acute-stage symptoms. Its affinity for adrenaline α1, serotonin 5-HT2C, histamine H1, and muscarinic M1 receptors is low, suggesting a lower likelihood of sedative action, weight gain, and influence on the metabolic system [
12]. Paliperidone is a major active metabolite of risperidone that has D2 receptor blocking activity and a more potent 5-HT2A receptor blocking activity and serves as a serotonin-dopamine antagonist [
13]. The preparation of oral paliperidone adopts a drug-delivery control system that uses osmotic pressure, enabling the administration of treatment once a day [
14]. Similar to risperidone, paliperidone is expected to be particularly effective against hallucination and delusion at the acute stage of schizophrenia, however, this drug is relatively likely to cause extrapyramidal symptoms and elevation in blood prolactin levels [
15]. Unlike the other SGAs, paliperidone is almost not affected by the enzymes involved in hepatic metabolism and is excreted primarily (60%) in the unchanged form into the urine, allowing the use of this drug in patients with mildly or moderately compromised hepatic function [
16]. Thus, the 3 study drugs differ in pharmacological profiles related to receptor affinity and have varying metabolic and formulation characteristics. In previous placebo-controlled and active-drug-controlled short-term comparative studies that used changes in psychiatric symptom scores as indicators, these drugs exhibited an efficacy that was comparable to that of the other SGAs and were found to have no noteworthy safety-profile problems compared with the other SGAs [
17‐
22]. Various disabilities arise from schizophrenia that exhibit largely unmet needs. Therefore, we may say that the collection of domestic evidence on these 3 drugs, which are marketed in Japan, is quite valuable.
The present work was designed as a study aimed at collecting evidence for the selection of drugs used for the treatment in patients with schizophrenia in clinical practice. The inclusion criteria were set so that the study can enroll not only patients having responded poorly to previous antipsychotic treatment, but also patients with poor tolerance to the antipsychotics used currently, and patients having received no antipsychotics. The evaluation of long-term outcome will use treatment discontinuation rate and remission rate as indicators for the following reasons: (1) this kind of evaluation emphasizes effectiveness and encompasses elements such as symptom control, safety, social activity improvement, and QOL improvement, thus requiring realistic, simple and quantitative indicators; and (2) recent naturalistic studies revealed the necessity of ensuring adherence to the dosing instructions as an indispensable factor to obtain effectiveness above a certain level, and the necessity of estimating the extent of social activity recovery, which is the final goal of schizophrenia treatment [
23,
24]. The recurrence of schizophrenia can reduce the social activity of patients. Therefore, it is important to determine how to prevent its recurrence. In addition, in the present study, the treatment discontinuation rate as a marker of adherence was adopted as the primary endpoint. The evaluation of this parameter is simplified by including discontinuation of treatment for any reason. The results of such analyses are expected to serve as the evidence for the selection of antipsychotics to be used under diverse healthcare setting in Japan. The analysis using the remission rate as an indicator of the potential for social activity recovery in patients with schizophrenia is meaningful. To evaluate the remission rate, we adopted the Andreasen definition (rating below mild on all 8 items of the PANSS for 6 consecutive months or more) [
5]. There are no uniform criteria for judging the recurrence of schizophrenia. However, hospitalization based on symptom aggravation or changes in PANSS or CGI scores is often used for the evaluation of relapse [
25]. Consequently, in the present study, these indicators are used in the evaluation of the recurrence. For the evaluation of social activity improvement, assessments of QOL using PSP and EQ-5D will also be carried out. In contrast with the previously reported CATIE study, which emphasized the evaluation of treatment discontinuation rate [
2], the present study focuses on the analysis of the treatment discontinuation rate, accompanied by analyses of secondary measures including remission rate and social activity, to evaluate the effectiveness of the study drugs. Considering that this study is randomized, interventional design, we set the study period as 104 weeks, enabling us to evaluate remission rate and improvement in social recovery in addition to the treatment discontinuation rate. The participants enrolled in this study also include the patients who received multiple antipsychotic medications. Switching to monotherapy is desirable from the viewpoints of improvement of adherence to treatment and alleviation of adverse reactions [
26]. Thus, the present study plans to examine the possibility of switching from the preceding multiple antipsychotic medications to a single antipsychotic. In addition, the comprehensive capacity of individual patients is evaluated using the Japanese version of the MacCAT-CR, thus allowing the assessment of the influence of decision-making capacity on the continuation of treatment and improvement in social activity.
The evaluation of effectiveness afforded by this study is expected to yield new findings regarding the 3 study drugs for SGA selection for patients with schizophrenia.
We planned to conduct a randomized effectiveness study on aripiprazole, blonanserin, and paliperidone in patients with schizophrenia who had not received antipsychotic medication, in whom previous medication had been suspended, or who needed a switch from the current medication. The study period is 104 weeks. The primary endpoint is treatment discontinuation rate. Secondary endpoints are remission rate, improvement in social activity, adverse events. This study is expected to yield evidence for the selection of SGAs from the viewpoint of long-term outcome in patients with schizophrenia.
Acknowledgments
This study is supported by a research grant from The Waksman Foundation of Japan, Inc.
Data and safety monitoring committee
The Data and Safety Monitoring Committee consists of the following members: Teruhiko Higuchi, National Center of Neurology and Psychiatry, Japan; Mitsukuni Murasaki, Institute of CNS Psychopharmacology, Japan; and Kunitoshi Kamijima, International University of Health and Welfare, Japan.
Competing interests
JI, TO and NI received research funding, grant, honoraria from Otsuka Pharmaceutical Co., Ltd., Dainippon Sumitomo Pharma Co., Ltd. and Janssen Pharmaceutical KK. KN received honoraria from Otsuka Pharmaceutical Co., Ltd., Dainippon Sumitomo Pharma Co., Ltd and Janssen Pharmaceutical KK. All authors have advisory role for Otsuka Pharmaceutical Co., Ltd., Dainippon Sumitomo Pharma Co., Ltd and Janssen Pharmaceutical KK.
Authors’ contributions
All authors conceived the study and its design, and made the draft manuscript. All of them read and approved the final manuscript.