Anhedonia – a diminished interest or pleasure in activities – is a core self-reported symptom of depression which is poorly understood and often resistant to conventional antidepressants. This symptom may occur due to dysfunction in one or more sub-components of reward processing: motivation, consummatory experience and/or learning. However, the precise impairments remain elusive. Dissociating these components (ideally, using cross-species measures) and relating them to the subjective experience of anhedonia is critical as it may benefit fundamental biology research and novel drug development.

Using a battery of behavioural tasks based on rodent assays, we examined reward motivation (Joystick-Operated Runway Task, JORT; and Effort-Expenditure for Rewards Task, EEfRT) and reward sensitivity (Sweet Taste Test) in a non-clinical population who scored high (N = 32) or low (N = 34) on an anhedonia questionnaire (Snaith–Hamilton Pleasure Scale).

Compared to the low anhedonia group, the high anhedonia group displayed marginal impairments in effort-based decision-making (EEfRT) and reduced reward sensitivity (Sweet Taste Test). However, we found no evidence of a difference between groups in physical effort exerted for reward (JORT). Interestingly, whilst the EEfRT and Sweet Taste Test correlated with anhedonia measures, they did not correlate with each other. This poses the question of whether there are subgroups within anhedonia; however, further work is required to directly test this hypothesis.

Our findings suggest that anhedonia is a heterogeneous symptom associated with impairments in reward sensitivity and effort-based decision-making.

Portable oxygen concentrators (POCs) are medical devices that use physical means to separate oxygen from the atmosphere to produce concentrated, medical-grade gas. Providing oxygen to low-resources environments, such as austere locations, military combat zones, rural Emergency Medical Services (EMS), and during disasters, becomes expensive and logistically intensive. Recent advances in separation technology have promoted the development of POC systems ruggedized for austere use. This review provides a comprehensive summary of the available data regarding POCs in these challenge environments.

PubMed, Google Scholar, and the Defense Technical Information Center were searched from inception to November 2021. Articles addressing the use of POCs in low-resource settings were selected. Three authors were independently involved in the search, review, and synthesis of the articles. Evidence was graded using Oxford Centre for Evidence-Based Medicine guidelines.

The initial search identified 349 articles, of which 40 articles were included in the review. A total of 724 study subjects were associated with the included articles. There were no Level I systematic reviews or randomized controlled trials.

Generally, POCs are a low-cost, light-weight tool that may fill gaps in austere, military, veterinary, EMS, and disaster medicine. They are cost-effective in low-resource areas, such as rural and high-altitude hospitals in developing nations, despite relatively high capital costs associated with initial equipment purchase. Implementation of POC in low-resource locations is limited primarily on access to electricity but can otherwise operate for thousands of hours without maintenance. They provide a unique advantage in combat operations as there is no risk of explosive if oxygen tanks are struck by high-velocity projectiles. Despite their deployment throughout the battlespace, there were no manuscripts identified during the review involving the efficacy of POCs for combat casualties or clinical outcomes in combat. Veterinary medicine and animal studies have provided the most robust data on the physiological effectiveness of POCs. The success of POCs during the coronavirus disease 2019 (COVID-19) pandemic highlights the potential for POCs during future mass-casualty events. There is emerging technology available that combines a larger oxygen concentrator with a compressor system capable of refilling small oxygen cylinders, which could transform the delivery of oxygen in austere environments if ruggedized and miniaturized. Future clinical research is needed to quantify the clinical efficacy of POCs in low-resource settings.

Approved treatments for bipolar depression are limited and associated with a spectrum of undesirable side effects. Lumateperone (lumateperone tosylate, ITI−007), a mechanistically novel antipsychotic that simultaneously modulates serotonin, dopamine, and glutamate neurotransmission, is FDA-approved for the treatment of schizophrenia. Lumateperone is currently being investigated for the treatment of bipolar depression (major depressive episodes [MDE] associated with bipolar I and bipolar II disorder). This Phase 3 randomized, double-blind, parallel-group, placebo-controlled multinational study (NCT03249376) investigated the efficacy and safety of lumateperone in patients with bipolar I or bipolar II disorder experiencing a MDE.

Patients (18 75 years) with a clinical diagnosis of bipolar I or bipolar II disorder who were experiencing a MDE (Montgomery-Åsberg Depression Rating Scale [MADRS] Total score =20 and a Clinical Global Impression Scale-Bipolar Version-Severity [CGI-BP-S] score =4 at screening and baseline) were randomized to lumateperone 42mg or placebo for 6 weeks. The primary and key secondary efficacy endpoints were change from baseline to Day 43 in MADRS total score and CGI-BP-S scores, respectively. Secondary efficacy outcomes included response (MADRS improvement = 50%) and remission (MADRS total score =12) at Day 43. Safety assessments included treatment emergent adverse events, laboratory parameters, vital signs, extrapyramidal symptoms (EPS), and suicidality.

In this study, 377 patients received treatment (placebo, n=189; lumateperone 42mg, n=188) and 333 completed treatment. Patients in the lumateperone 42-mg group had significantly greater mean improvement on MADRS total score change from baseline to Day 43 compared with placebo (least squares mean difference [LSMD]=-4.6; 95% confidence interval [CI]=-6.34, −2.83; effect size vs placebo [ES]=-0.56; P<.0001). Lumateperone treatment was associated with significant MADRS improvement in both patients with bipolar I (LSMD=-4.0; 95% CI=-5.92, −1.99; ES=-0.49; P<.0001) and bipolar II (LSMD=-7.0; 95% CI=-10.92, −3.16; ES=-0.81; P=.0004). The lumateperone 42-mg group also had significantly greater mean improvement in CGI-BP-S total score compared with placebo (LSMD=-0.9; 95% CI=-1.37, −0.51; ES=-0.46; P<.001). Lumateperone compared with placebo had significantly greater MADRS response rate (51.1% vs 36.7%; odds ratio=2.98; P<.001) and remission rates (P=.02) at Day 43. Lumateperone treatment was well tolerated, with minimal risk of EPS, metabolic, and prolactin side effects.

Lumateperone 42 mg significantly improved depression symptoms in both patients with bipolar I and bipolar II depression. Lumateperone was generally well tolerated. These results suggest that lumateperone 42 mg may be a promising new treatment for bipolar depression associated with bipolar I or bipolar II disorder.

Intra-Cellular Therapies, Inc.

Current treatments for schizophrenia are often associated with increased rates of metabolic syndrome (MetSy). MetSy is defined as meeting 3 of the following 5 criteria: waist circumference >40in (men) or >35in (women), triglycerides =150mg/dL, high density lipoprotein cholesterol (HDL) <40mg/dL (men) or <50mg/dL (women), systolic blood pressure (BP) =130mmHg or diastolic BP =85mmHg, fasting glucose =100mg/dL. Patients with MetSy have an elevated risk of developing type II diabetes and increased mortality due to cardiovascular disease. Lumateperone (lumateperone tosylate, ITI−007), a mechanistically novel antipsychotic that simultaneously modulates serotonin, dopamine, and glutamate neurotransmission, is FDA approved for the treatment of schizophrenia. This distinct pharmacological profile has been associated with favorable tolerability and a low risk of adverse metabolic effects in clinical trials. This post hoc analysis of 2 randomized, double-blind, placebo-controlled studies of patients with an acute exacerbation of schizophrenia compared rates of MetSy with lumateperone and risperidone. Data from an open-label long-term trial of lumateperone were also evaluated.

The incidence and shift in MetSy were analyzed in data pooled from 2 short-term (4 or 6 week) placebo- and active-controlled (risperidone 4mg) studies of lumateperone 42mg (Studies 005 and 302). The pooled lumateperone data were compared with data for risperidone. Data from an open-label 1-year trial (Study 303) evaluated MetSy in patients with stable schizophrenia switched from prior antipsychotic (PA) treatment to lumateperone 42mg.

In the acute studies (n=256 lumateperone 42mg, n=255 risperidone 4mg), rates of MetSy were similar between groups at baseline (16% lumateperone, 19% risperidone). At the end of treatment (EOT), MetSy was less common with lumateperone than with risperidone (13% vs 25%). More lumateperone patients (46%) compared with risperidone (25%) patients improved from having MetSy at baseline to no longer meeting MetSy criteria at EOT. Conversely, more patients on risperidone than on lumateperone developed MetSy during treatment (13% vs 5%). Differences in MetSy conversion rates were driven by changes in triglycerides and glucose. In the long-term study (n=602 lumateperone 42mg), 33% of patients had MetSy at PA baseline. Thirty-six percent of patients (36%) with MetSy at PA baseline improved to no longer meeting criteria at EOT. Fewer than half that percentage shifted from not meeting MetSy criteria to having MetSy (15%).

In this post hoc analysis, lumateperone 42mg patients had reduced rates of MetSy compared with risperidone patients. In the long-term study, patients with MetSy on PA switched to lumateperone 42mg had a reduction in the risk of MetSy. These results suggest that lumateperone 42mg is a promising new treatment for schizophrenia with a favorable metabolic profile.

Intra-Cellular Therapies, Inc.

Lumateperone (lumateperone tosylate, ITI-007) is an investigational drug for the treatment of schizophrenia, bipolar depression, and other disorders. Lumateperone has a unique mechanism of action that simultaneously modulates serotonin, dopamine, and glutamate neurotransmission. This may provide advantages in the treatment of the broad symptoms associated with schizophrenia, including negative and depression symptoms. In 2 previous placebo-controlled trials in patients with acute schizophrenia, lumateperone 42mg (ITI-007 60mg) demonstrated statistically significant improvement in the Positive and Negative Syndrome Scale (PANSS) Total score compared with placebo. In these studies, lumateperone was well tolerated with a safety profile similar to placebo. This open-label long-term study evaluated the safety and effectiveness of lumateperone 42mg in patients with schizophrenia and stable symptoms.

Patients with stable schizophrenia were treated for up to 1 year with lumateperone 42mg. Safety assessments included adverse events (AEs), body weight, laboratory parameters, and extrapyramidal symptoms (EPS)/motor symptom assessments. Efficacy analyses included evaluation of changes in PANSS Total score and in depression symptoms, as measured by the Calgary Depression Scale for Schizophrenia (CDSS).

In the 1-year open-label study, 602 patients received at least 1 dose of lumateperone 42mg; at the time of this interim analysis, 107 patients had completed 1 year of treatment. Only 4 TEAEs occurred in ≥5% of patients (weight decrease, dry mouth, headache and diarrhea); the majority of AEs were mild or moderate in intensity. Most metabolic parameters and mean prolactin levels decreased from SOC baseline, as did mean body weight and BMI. Based on AE reporting and EPS/motor symptom scales, lumateperone treatment was associated with minimal EPS risk. Lumateperone 42mg treatment was associated with significant reductions in PANSS Total score from baseline, with continuing PANSS improvement throughout the study. In patients with moderate-to-severe depression symptoms at baseline (CDSS>5), mean CDSS scores decreased from 7.4 (baseline) to 3.1 (Day 300); 60% of patients met CDSS response criteria (50% improvement from baseline) by Day 75 and this response rate was maintained through day 300. Similar magnitude of CDSS improvement was seen regardless of concurrent antidepressant therapy.

In long-term treatment, lumateperone was associated with minimal metabolic, EPS, and cardiovascular safety issues relative to current SOC antipsychotic therapy. Lumateperone improved schizophrenia symptoms with continued long-term treatment. In patients with moderate-to-severe depression symptoms at baseline, lumateperone treatment was associated with marked improvement in CDSS scores. These data are consistent with and extend data previously reported in placebo-controlled studies in patients with acute schizophrenia treated with lumateperone.

Supported by funding from Intra-Cellular Therapies, Inc.

Lumateperone (ITI-007) is in late-phase clinical development for schizophrenia. Lumateperone has a unique mechanism of action that modulates serotonin, dopamine, and glutamate neurotransmission. This pooled analysis of lumateperone in 3 randomized, double-blind, placebo-controlled studies was conducted to evaluate the safety and tolerability of lumateperone 42mg (ITI-007 60mg).

Data were pooled from the 3 controlled late-phase studies of lumateperone 42mg in patients with acute exacerbation of schizophrenia. Safety assessments of all patients who received at least one dose of any treatment included treatment-emergent adverse events (TEAEs), changes in laboratory parameters, extrapyramidal symptoms (EPS), and vital signs.

The safety population comprised 1,073 patients (placebo [n=412], lumateperone 42mg [n=406], risperidone [n=255]). TEAEs that occurred in the lumateperone 42mg group at a rate of ≥5% and twice placebo were somnolence/sedation (24.1% vs 10.0%) and dry mouth (5.9% vs 2.2%). Rates of discontinuation due to TEAEs with lumateperone 42mg (0.5%) were similar to placebo (0.5%) and lower than risperidone (4.7%). Mean change in weight and rates of EPS-related TEAEs were less for lumateperone 42mg and placebo patients than risperidone patients. Mean change from baseline in metabolic parameters were similar or smaller for lumateperone 42mg vs placebo. Mean changes were notably higher in risperidone patients vs lumateperone 42mg and placebo for glucose, cholesterol, triglycerides, and prolactin.

In this pooled analysis, lumateperone 42mg showed good tolerability with potential benefits over risperidone for metabolic, prolactin, and EPS risks. The only TEAE that occurred in >10% of lumateperone patients was somnolence/sedation, which was impacted by morning administration; in subsequent studies that administered lumateperone in the evening, somnolence/sedation rates were markedly reduced. These results suggest that lumateperone 42mg may be a promising new treatment for schizophrenia.

Supported by funding from Intra-Cellular Therapies, Inc.