All current antipsychotics have direct dopamine (DA) D2 receptor activity, which is associated with problems such as dysphoria, EPS, or prolactin elevation. Muscarinic receptor agonists have shown antipsychotic-like activity across preclinical models and clinical trials. This poster reviews preclinical evidence as to how muscarinic receptor agonists, such as the M1/M4 preferring agonist xanomeline, might have clinically relevant antipsychotic effects.

Highlight the novel mechanisms through which muscarinic receptor agonists are associated with antipsychotic effects without having any direct dopaminergic D2 receptor activity.

The muscarinic receptor family is composed of 5 G protein-coupled receptors (GPCRs). One of the leading hypotheses explaining the antipsychotic activity of muscarinic receptor agonists is preclinical studies of muscarinic receptor modulation of those DA circuits associated with psychosis. Both M1 and M4 receptors are expressed in DA neural circuits implicated in psychosis, and provide unique regulation of these circuits. Xanomeline has both functional M1 and M4 receptor agonist activity, and shows robust antipsychotic-like effects in several animal models that require the presence of functional M1 and M4 receptors. M4 receptors are autoreceptors on cholinergic neurons that regulate DA circuits in two locations: ventral tegmental area (VTA) and nucleus accumbens (NAc). Cholinergic-rich neurons from the hindbrain at the VTA, where they release acetylcholine (ACh) into DA-rich synaptic spaces. M4 autoreceptors are present on these neurons, and their activation reduces ACh release and lowers ambient synaptic ACh concentrations, leading to reduced DA cell firing. Cholinergic interneurons residing in the NAc also express M4 autoreceptors. These ACh interneurons regulate ACh release with M4 activation also turning off ACh release. Therefore, M4 receptors serve as DA regulators at VTA and NAc, both key sites for dopamine’s role in psychotic processes. M1 receptors regulate DA circuits in a different, “top down” manner. M1 receptors are found on cortical inhibitory interneurons. When activated, inhibitory drive onto excitatory output neurons is enhanced, which leads to reduced excitatory tone to VTA DA neurons.

Over the last 25 years, a growing body of evidence has shown potential for muscarinic receptor agonists to become a new class of medicines with potent antipsychotic activity. Preclinical data at micro-and macro-circuit levels suggest that the M1 and M4 receptor subtypes are most relevant in the regulation of DA circuits. The antipsychotic effects of muscarinic agonists effects may arise from influencing these key muscarinic receptor subtypes that are integral to the regulation of DA neural circuits. In summary, there has been great progress in understanding the potential for muscarinic receptor agonists for the treatment of psychosis.

Karuna Therapeutics

The randomized, controlled, phase 3b ALPINE study evaluated efficacy and safety of a 2-month formulation of aripiprazole lauroxil (AL) initiated with a 1-day regimen during hospitalization for an acute exacerbation of schizophrenia; paliperidone palmitate (PP) was included as an active control. The primary efficacy outcome, within-group change from baseline in PANSS total score at 4 weeks, was previously reported. Here we report additional exploratory PANSS subscale endpoints and patient-reported outcomes (PROs).

Adults aged 18–65 years were enrolled as inpatients and randomized to AL 1064 mg q8wk or PP 156 mg q4wk and discharged after 2 weeks of study treatment if clinically stable. Patients were followed as outpatients through week 25. Exploratory efficacy endpoints were PANSS subscale (Positive, Negative, and General) and Clinical Global Impression-Severity (CGI-S) scores. The Burden Assessment Scale was administered to patients’ nonprofessional caregivers (family member or friend). Exploratory PROs (Quality of Life Enjoyment and Satisfaction Questionnaire Short Form [Q-LES-Q-SF] and Medication Satisfaction Questionnaire) were assessed during the outpatient period. Within-group changes in PANSS subscales and CGI-S scores from baseline through week 25 were analyzed for AL and PP using mixed models with repeated measures. PROs were summarized based on observed data.

In total, 200 patients were randomized (AL, n=99; PP, n=101); 99 (AL, n=56; PP, n=43) completed the 25-week study. PANSS Positive, Negative, and General subscale scores improved with AL treatment as measured by change from baseline to week 25 (least squares [LS] mean [95% CI]: Positive, −7.0 [−8.1, −6.0]; Negative, −3.7 [−4.7, −2.8]; General, −11.1 [−12.7, −9.5]), as did CGI-S scores (LS mean [95% CI] change at week 25: –1.2 [–1.4 –1.0]). Caregiver burden decreased over the treatment period, with the largest decline noted at week 9 for AL patients’ caregivers (mean change from baseline at week 9: −8.4; week 25: −8.9). Over weeks 5, 9, and 17, 70.8%−74.7% of AL-treated patients were somewhat or very satisfied with treatment. Mean Q-LES-Q-SF total scores were stable. With PP, PANSS subscale and CGI-S scores improved from baseline to study end (LS mean [95% CI] changes at week 25: Positive, −7.1 [−8.2, −5.9]; Negative, −3.5 [−4.6, −2.5]; General, −10.4 [−12.1, −8.6]; CGI-S, −1.2 [−1.5, −1.0]). Mean caregiver burden decreased (week 9: −8.8; week 25: −9.2). Most PP patients were satisfied or very satisfied with treatment (64.7%−69.3% at weeks 5, 9, and 17), and mean Q-LES-Q-SF total scores were stable.

In ALPINE, patients who initiated AL or PP in the hospital and continued treatment during outpatient care experienced improvement in schizophrenia symptoms and reported satisfaction with medication, decreased caregiver burden, and stable quality of life.

Alkermes, Inc.

Evaluate efficacy and safety of a 2-month dose of aripiprazole lauroxil (AL) with a 1-day initiation regimen during hospitalization for an acute exacerbation of schizophrenia.

In the phase 3b double-blind ALPINE study, adults with schizophrenia were randomized to AL (AL NanoCrystal® Dispersion + oral aripiprazole 30 mg day 1; AL 1064 mg day 8 and every 8 weeks) or paliperidone palmitate (PP 234 mg day 1; PP 156 mg day 8 and every 4 weeks). Patients were discharged after 2 weeks of hospitalization and followed through week 25. Primary endpoint was within-group changes in PANSS total score from baseline to week 4 (observed cases). Secondary analyses included within-group changes at weeks 9 and 25 (observed) and between-group comparisons at weeks 4, 9, and 25 (MMRM). Adverse events (AEs) were monitored throughout the study.

200 patients were randomized (AL, n=99; PP, n=101); 56.6% and 42.6%, respectively, completed the study. Within-group changes from baseline in PANSS were −17.4 for AL and −20.1 for PP at week 4 (both groups, P<0.001) and continued to decline at weeks 9 (AL, −19.8; PP, −22.5) and 25 (AL, −23.3; PP, −21.7). The change in PANSS over time was similar between groups. AEs occurring in ≥10% of patients in either group were injection site pain (AL, 17.2%; PP, 24.8%), akathisia (AL, 9.1%; PP, 10.9%), and weight increased (AL, 9.1%; PP, 16.8%).

AL and PP were effective and well-tolerated for initiating treatment of schizophrenia in the hospital and continuing in the outpatient setting.

This study was funded by Alkermes, Inc.

Patient-reported outcomes and preferences rely on reports of the status of a patient’s health condition that comes directly from the patient, without interpretation or qualification by clinicians or investigators. Patient-reported outcomes and preferences have become an accepted approach in drug development. As part of this effort, we assessed the relative importance to patients with schizophrenia of trying a new antipsychotic that might improve symptoms in the context of common antipsychotic side effects, especially weight gain. Information from surveys such as this one can provide pilot guidance about what might be acceptable versus unacceptable trade-offs when considering new therapies for schizophrenia.

We prospectively administered a cross-sectional survey to 250 patients with clinical diagnoses of schizophrenia or schizoaffective disorder, aged ≥18 years, from five US outpatient community clinics, regarding the importance of efficacy and side effects on treatment decisions involving medications. Sixty-four percent (n=160) of the patients were male; mean age was 43 years (range: 18–72 years); mean weight was 91 kg (range: 49–182 kg); and mean body mass index was 30.3 kg/m2 (range: 15.3–63.3 kg/m2).

Patients rated both efficacy and side effects as important attributes of medication for schizophrenia treatment, with 88.5% identifying the ability to think more clearly as an important property of their medication. Patients identified efficacy and side effects as important drivers to take their prescribed medicine (endorsed as very or most important by 94.3% and 84.0% of patients, respectively). Patients identified weight gain, physical restlessness and somnolence as significant side effects of current treatments for schizophrenia (very/most important by 61.5%, 60.4%, and 58.9%, respectively). When asked about willingness to change antipsychotics, anticipated weight gain had a strong negative influence on willingness to try a new antipsychotic, with 44.9% of patients declining to try a medication that would lead to a weight gain of 3–5 kg, and 70.8% of patients declining for an anticipated weight gain of 5–9kg.

Patients living with schizophrenia or schizoaffective disorder are influenced by many factors when considering whether to take their prescribed medication, including efficacy and side effects. It is important for clinicians to assess patient-specific concerns and develop a comprehensive treatment plan to maximize adherence to prescribed therapies.

Funding Acknowledgements: This study was funded by Alkermes, Inc.

One of the challenges in schizophrenia long-term trials is that clinical outcomes are often confounded by covert nonadherence to prescribed oral antipsychotics. This is a post hoc analysis (>2 years) of the symptoms and illness trajectory of patients treated with the long-acting injectable (LAI) antipsychotic aripiprazole lauroxil (AL). As adherence to LAIs can be monitored, these data could assess outcome trajectories unaffected by medication discontinuations that may occur with oral antipsychotics.

The efficacy and safety of once-monthly AL (441 or 882mg) for the treatment of schizophrenia were previously demonstrated in a phase 3 trial, followed by a 52-week, long-term safety study of two AL doses (441 or 882mg once monthly; patients continuing from the phase 3 study remained on their fixed AL dose [NCT01626456]), after which patients could enroll in a second long-term extension study. Patients entering the second long-term study continued on their fixed AL dose, with a variable follow-up period of up to 128 additional weeks (NCT01895452). In this post hoc analysis, the extension studies were combined to provide continuous outcome data over 2 years’ follow-up. The 12-week assessment visit (rather than the first visit) in the first extension study was chosen as the baseline to account for patients entering this study with variable AL exposure histories (with/without prior AL exposure). We report on the trajectory of symptoms and illness severity for >2 years (up to 112weeks) after the 12-week visit using the Positive and Negative Syndrome Scale (PANSS) total and Clinical Global Impression–Severity (CGI-S) scale scores. Course of illness was measured as the difference in PANSS and CGI-S scale scores within dose groups from baseline to end of follow-up, analyzed using MMRM.

Overall, 432/478 patients entering the initial 52-week study were included in the post hoc analysis. For the AL 441 and 882mg groups, respectively, baseline scores (mean±SD) were 59.91±16.25 and 56.27±12.89 (PANSS), and 2.99±0.97 and 2.79±0.79 (CGI-S scale). Approximately 49% of patients (211/432) remained for the entire 112-week follow-up. Over this period, the trajectory of PANSS scores improved significantly compared with baseline for both the 441 and 882mg groups, with changes from baseline (least squares mean±SE) of −5.46±0.92 (P<.0001) and −4.99±0.53 (P<.0001), respectively. CGI-S scale scores had similar improvement: changes from baseline of −0.32±0.07 (P<.0001) and −0.28±0.04 (P<.0001) for the AL 441 and 882mg groups, respectively. Overall, AL was well tolerated, with a safety profile over a 2-year follow-up that was consistent with the initial 52-week safety results.

This post hoc analysis demonstrates the safety and continued therapeutic efficacy of long-term treatment with AL in patients with schizophrenia. There were no apparent dose differences in the trajectory of symptom changes over the course of a 2-year follow-up.

Funding Acknowledgements: This study was funded by Alkermes, Inc.

Slow release is a fundamental feature of long-acting injectable (LAI) antipsychotics. This property allows continuous drug exposure between dosing intervals. However, there can be a significant delay between giving the first LAI dose and achievement of efficacious plasma concentrations. This time period requires additional pharmacologic intervention. Until now, this delay was addressed with one of two strategies: 1) continuing with supplemental oral antipsychotic, or 2) giving more LAI up front (e.g. loading dose). A third strategy has now been developed to reduce the time needed for oral supplementation when starting the LAI aripiprazole lauroxil (AL) from 21days to 1day. A nano-crystalline milled dispersion of AL (ALNCD; brand name ARISTADA INITIO™) was formulated by reducing the AL particle diameter from micron-size particles to nanometer- sized particles. ALNCD has faster dissolution and a shorter half-life than AL and is designed to be used as a single injection along with a single oral aripiprazole dose of 30mg as a 1-day alternative to the 21days of oral aripiprazole supplementation. Here we provide an overview of the new 1-day initiation regimen for starting AL treatment, and demonstrate the relative contributions of each of its components.

A blinded, randomized, phase 1, pharmacokinetic (PK), and safety study compared the 1-day initiation regimen with the 21-day oral aripiprazole regimen. A combination of observed data, and population pharmacokinetic model–based simulations were used to plot plasma aripiprazole concentrations of single doses of ALNCD, 30mg oral aripiprazole, and AL, individually, and all three combined.

The PK profiles of the 1-day and 21-day initiation regimens (both in conjunction with either 441mg or 882mg doses of AL) were comparable, with therapeutically relevant aripiprazole levels achieved within 4days of treatment initiation. The safety profile of the 1-day initiation regimen was similar to the 21-day initiation regimen, and consistent with that of AL. Aripiprazole concentration–time profiles demonstrated that each component delivered aripiprazole to the systemic circulation at different time periods, with the 30mg dose of oral aripiprazole predominant in the first week, followed by ALNCD, and then AL.

The 1-day initiation regimen is well-tolerated and a suitable alternative to 21days of oral aripiprazole supplementation for starting AL. Each component of the 1-day initiation regimen, together with AL, is necessary to provide continuous coverage from treatment initiation until the next regularly scheduled AL injection.

Funding Acknowledgements: This study was funded by Alkermes Inc.

Safety and tolerability of long-term treatment with the long-acting antipsychotic aripiprazole lauroxil (AL) were evaluated in patients with schizophrenia.

This was an international, multicenter, phase 3, 52-week safety study of 2 fixed doses of AL (441 mg or 882 mg intramuscular every 4 weeks). Safety endpoints included adverse events (AEs) and extrapyramidal symptoms (EPS) including akathisia, injection-site reactions (ISRs), and clinically relevant changes in metabolic and endocrine values.

Of 478 patients entering this study, 236 (49%) continued from a previous 12-week, phase 3 efficacy study of AL, and 242 (51%) were newly enrolled. Overall, 77% and 23% of patients received AL 882 mg (N = 368) and 441 mg (N = 110), respectively. AEs occurred in 50.4% of patients; most were mild (28.7%) or moderate (18.2%). The most common AEs were insomnia (8.4%) and increased weight (5.0%). Akathisia was reported as an AE in 3.8% of the overall population, with higher rates in patients initiating AL on study entry than those continuing on AL. EPS-related AEs occurred in 9.4% of patients, and AEs related to metabolic parameters were reported in 4.6% of patients. Weight gain was minimal (0.8 kg), and no clinically relevant changes were observed for metabolic parameters. The overall incidence of ISRs was 3.8%; most were associated with the initial injections in patients receiving their first injection in this study.

Long-term treatment with AL is generally well tolerated, with a safety profile consistent with that of oral aripiprazole. It is a suitable option for patients with schizophrenia.

Switching antipsychotic medications is common in patients with schizophrenia who are experiencing persistent symptoms or tolerability issues associated with their current drug regimen. This analysis assessed the safety of switching from an oral antipsychotic to the long-acting injectable antipsychotic aripiprazole lauroxil (AL).

This was a post hoc analysis of outpatients with schizophrenia who were prescribed an oral antipsychotic and who enrolled in an international, open-label, long-term (52-week) safety study of AL. The analysis focused on the first 3 injections of AL 882 mg over 12 weeks, divided into the immediate 4-week crossover period between the first and second AL injections (initiation phase) and the subsequent 8 weeks (stabilization phase). Patients were grouped by preswitch oral antipsychotic medication, and safety and clinical symptoms were assessed.

In total, 190 patients had switched from one of the following oral antipsychotic medications: aripiprazole, conventional antipsychotics, risperidone/paliperidone, olanzapine, or quetiapine. The 12-week completion rate was high (92.1%) and similar across the different preswitch oral antipsychotic groups. Overall, adverse event (AE) rates experienced over 12 weeks were modest; no AEs were considered serious. The most common AEs in the initiation phase were injection site pain (5.8%), insomnia (5.8%), and akathisia (3.2%). No apparent relationship was observed between preswitch medication and early-onset AEs. Mean Positive and Negative Syndrome Scale total scores remained stable during this period across preswitch antipsychotic groups.

Switching from an oral antipsychotic to AL was feasible in an outpatient setting for patients with schizophrenia, and the 12-week retention rate was favorable.

To evaluate the long-term safety and tolerability of lurasidone in schizophrenia and schizoaffective disorder patients switched to lurasidone.

Patients in this multicenter, 6-month open-label, flexible-dose, extension study had completed a core 6-week randomized trial in which clinically stable, but symptomatic, outpatients with schizophrenia or schizoaffective disorder were switched to lurasidone. Patients started the extension study on treatment with the same dose of lurasidone taken at study endpoint of the 6-week core study; following this, lurasidone was flexibly dosed (40–120 mg/day), if clinically indicated, starting on Day 7 of the extension study. The primary safety endpoints were the proportion of patients with treatment emergent adverse events (AEs), serious AEs, or who discontinued due to AEs. Secondary endpoints included metabolic variables and measures of extrapyramidal symptoms and akathisia, as well as the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impressions-Severity (CGI-S), and the Calgary Depression Scale for Schizophrenia (CDSS). The study was conducted from August 2010 to November 2011.

Of the 198 patients who completed the 6-week core study, 149 (75.3%) entered the extension study and 148 received study medication. A total of 98 patients (65.8%) completed the 6-month extension study. Lurasidone 40, 80, and 120 mg were the modal daily doses for 19 (12.8%), 65 (43.9%), and 64 (43.2%) of patients, respectively. Overall mean (SD) daily lurasidone dose was 102.0 mg (77.1). The most commonly reported AEs were insomnia (13 patients [8.8%]), nausea (13 patients [8.8%]), akathisia (12 patients [8.1%]), and anxiety (9 patients [6.1%]). A total of 16 patients (10.8%) had at least one AE leading to discontinuation from the study. Consistent with prior studies of lurasidone, there was no signal for clinically relevant adverse changes in body weight, lipids, glucose, insulin, or prolactin. Movement disorder rating scales did not demonstrate meaningful changes. Treatment failure (defined as any occurrence of discontinuation due to insufficient clinical response, exacerbation of underlying disease, or AE) was observed for 19 patients (12.8% of patients entering) and median time to treatment failure was 58 days (95% CI 22–86). The discontinuation rate due to any cause was 50/148 (33.8%), and median time to discontinuation was 62 days (95% CI 30–75). The mean PANSS total score, mean CGI-S score, and mean CDSS score decreased consistently from core study baseline across extension visits, indicating an improvement in overall condition.

In this 6-month, open-label extension study, treatment with lurasidone was generally well-tolerated with sustained improvement in efficacy measures observed in outpatients with schizophrenia or schizoaffective disorder who had switched to lurasidone from a broad range of antipsychotic agents.