Recently Approved and Upcoming Treatments for Narcolepsy

Improvement in sleep latency with extended-release once-nightly sodium oxybate for the treatment of adults with narcolepsy: Analysis from the phase 3 REST-ON clinical trial

Background

In the REST-ON clinical trial (NCT02720744), mean sleep latency on the Maintenance of Wakefulness Test (MWT) was significantly improved with extended-release once-nightly sodium oxybate (ON-SXB) vs placebo (P < 0.001) in participants with narcolepsy. This post hoc analysis assessed response to treatment and improvement in excessive daytime sleepiness.

Methods

Participants with narcolepsy aged ≥16 years were randomized 1:1 to receive ON-SXB (4.5 g, week 1; 6 g, weeks 2-3; 7.5 g, weeks 3-8; and 9 g, weeks 9-13) or placebo. Mean sleep latency on the MWT was measured across 5 trials of ≤30 min each. Post hoc assessments included percentage of participants whose sleep latency improved ≥5, ≥10, ≥15, and ≥20 min and with a mean sleep latency of 30 min.

Results

Significantly more participants receiving ON-SXB vs placebo experienced increased mean sleep latency ≥5 min (all doses P < 0.001), ≥10 min (all doses P < 0.001), ≥15 min (6 and 7.5 g, P < 0.001; 9 g, P < 0.01), and ≥20 min (6 g, P < 0.01; 7.5 g, P < 0.001; 9 g, P < 0.05). More participants receiving ON-SXB had mean sleep latency of 30 min vs placebo (6 g, 5.7 % vs 0 %, respectively [P < 0.05]; 7.5 g, 10.5 % vs 1.3 % [P < 0.05]; 9 g, 13.2 % vs 5.1 % [P = 0.143]).

Conclusions

Significantly more participants who received ON-SXB experienced increased mean sleep latency ≥5 to ≥20 min; at the 2 highest doses, >10 % remained awake for the entirety of the MWT. ON-SXB offers a once-at-bedtime treatment option for adults with narcolepsy.

Expanding the Use of Benzothioxanthene Imides to Photochemistry: Eco-Friendly Aerobic Oxidation of Sulfides to Sulfoxides

The sulfoxide moiety is one of the most commonly utilized groups in pharmaceutical and industrial chemistry. The need for sustainability and easy accessibility to sulfoxide moieties is deemed necessary, due to its ubiquity in natural products and potentially pharmaceutically active compounds. In this context, we report herein a sustainable, aerobic and environmentally friendly photochemical protocol based on the use of a benzothioxathene imide as the photocatalyst to selectively oxidize sulfides under mild irradiation (456 nm), in very low catalyst loading (0.01 mol %) and on water. In addition, to demonstrate the compatibility of our protocol with wide scope of substrates, the latter was successfully applied to the synthesis of the biologically-active Sulforaphane and Modafinil.

The Changed Nocturnal Sleep Structure and Higher Anxiety, Depression, and Fatigue in Patients with Narcolepsy Type 1

Purpose

This study aimed to evaluate nocturnal sleep structure and anxiety, depression, and fatigue in patients with narcolepsy type 1 (NT1).

Methods

Thirty NT1 patients and thirty-five healthy controls were enrolled and evaluated using the Epworth sleepiness scale (ESS), Generalized Anxiety Disorder-7, Patient Health Questionnaire-9, Fatigue Severity Scale (FSS), polysomnography, multiple sleep latency test, and brain function state monitoring. Statistical analyses were performed using SPSS Statistics for Windows, version 23.0. Benjamini-Hochberg correction was performed to control the false discovery rate.

Results

Apart from typical clinical manifestations, patients with NT1 are prone to comorbidities such as nocturnal sleep disorders, anxiety, depression, and fatigue. Compared with the control group, patients with NT1 exhibited abnormal sleep structure, including increased total sleep time (P adj=0.007), decreased sleep efficiency (P adj=0.002), shortening of sleep onset latency (P adj<0.001), elevated wake after sleep onset (P adj=0.002), increased N1% (P adj=0.006), and reduced N2%, N3%, and REM% (P adj=0.007, P adj<0.001, P adj=0.013). Thirty-seven percent of patients had moderate to severe obstructive sleep apnea-hypopnea syndrome. And sixty percent of patients were complicated with REM sleep without atonia. Patients with NT1 displayed increased anxiety propensity (P adj<0.001), and increased brain fatigue (P adj=0.020) in brain function state monitoring. FSS scores were positively correlated with brain fatigue (P adj<0.001) and mean sleep latency was inversely correlated with FSS scores and brain fatigue (P adj=0.013, P adj=0.029). Additionally, ESS scores and brain fatigue decreased after 3 months of therapy (P=0.012, P=0.030).

Conclusion

NT1 patients had abnormal nocturnal sleep structures, who showed increased anxiety, depression, and fatigue. Excessive daytime sleepiness and fatigue improved after 3 months of treatment with methylphenidate hydrochloride prolonged-release tablets in combination with venlafaxine.

A Comprehensive Review of Solriamfetol to Treat Excessive Daytime Sleepiness

Purpose of Review

This is a comprehensive review of the literature regarding the use of Solriamfetol for excessive daytime sleepiness. It covers the background and current therapeutic approaches to treating excessive daytime sleepiness, the management of common comorbidities, and the existing evidence investigating the use of Solriamfetol for this purpose.

Recent Findings

Excessive daytime sleepiness leads to worse quality of life, a medical sequela and significant economic cost. There are multiple phenotypes of excessive daytime sleepiness depending on the comorbidity making treatment challenging. Due to the complexity of etiology there is not a cure for this ailment. Solriamfetol is a norepinephrine/dopamine dual reuptake antagonist that can be used to manage daytime sleepiness. Solriamfetol was first approved by the FDA in 2018 for use in excessive daytime sleepiness associated with obstructive sleep apnea and narcolepsy. Ongoing literature has proved this drug to be a safe and effective alternative pharmacotherapy.

Summary

Recent epidemiological data estimate up to one-third of the general adult population suffers from excessive daytime sleepiness. There is no cure to daytime somnolence and current pharmacotherapeutic regimens have worrisome side effect profiles. Solriamfetol is a new class of drug that offers a safe and effective alternative option for clinical providers treating excessive daytime sleepiness.

The Burden of Narcolepsy in Adults: A Population Sampling Study Using Personal Media

OBJECTIVE

To obtain insight in the spectrum of narcolepsy symptoms and associated burden in a large cohort of patients.

METHODS

We used the Narcolepsy Monitor, a mobile app, to easily rate the presence and burden of 20 narcolepsy symptoms. Baseline measures were obtained and analyzed from 746 users aged between 18 and 75 years with a reported diagnosis of narcolepsy.

RESULTS

Median age was 33.0 years (IQR 25.0-43.0), median Ullanlinna Narcolepsy Scale 19 (IQR 14.0-26.0), 78% reported using narcolepsy pharmacotherapy. Excessive daytime sleepiness (97.2%) and lack of energy were most often present (95.0%) and most often caused a high burden (79.7% and 76.1% respectively). Cognitive symptoms (concentration 93.0%, memory 91.4%) and psychiatric symptoms (mood 76.8%, anxiety/panic 76.4%) were relatively often reported to be present and burdensome. Conversely, sleep paralysis and cataplexy were least often reported as highly bothersome. Females experienced a higher burden for anxiety/panic, memory, and lack of energy.

CONCLUSIONS

This study supports the notion of an elaborate narcolepsy symptom spectrum. Each symptom's contribution to the experienced burden varied, but lesser-known symptoms did significantly add to this as well. This emphasizes the need to not only focus treatment on the classical core symptoms of narcolepsy.

Tetrad of Narcolepsy Type 1: Treatment and Management

Narcolepsy is a chronic condition that brings about excessive daytime sleepiness. It can be classified into two types: narcolepsy type 1 (presence of cataplexy, which is marked by weakness of muscles) and narcolepsy type 2 (without cataplexy). It is generally underdiagnosed, which results in delayed diagnosis of the condition. It has more prevalence in the United States of America as compared to India. The narcoleptic tetrad consists of excessive daytime sleepiness (EDS), cataplexy, sleep paralysis, and hypnagogic hallucinations. Rapid eye movement (REM) sleep behavior disorder is another characteristic feature. Research about narcolepsy has been carried out for about 145-150 years, but it is only in the last 18-20 years that there has been advancement in the underlying pathophysiology, diagnosis, and, thus, availability of better treatment. Both pharmacological and non-pharmacological methods are preferred in treating narcolepsy, yet there is no cure for it. Since the knowledge regarding this condition is very limited, it is often misunderstood, and dealing with it is mentally and socially draining, often causing anxiety in the patients, feeling of social isolation, and other significant impacts on the quality of living. Raising awareness about narcolepsy is vital to prevent further medical attention delays.

Pitolisant-supported bridging during drug holidays to deal with tolerance to modafinil in patients with narcolepsy

STUDY OBJECTIVES

Modafinil is a common treatment for excessive daytime sleepiness (EDS) in narcolepsy. The long-term use of modafinil can lead to tolerance with the loss of efficacy and the continuous increase of its dose. Pharmacological strategies to deal with the tolerance to modafinil are lacking. We investigated the efficacy and safety of pitolisant-supported bridging during drug holidays in patients with tolerance to modafinil.

METHODS

Narcolepsy patients on monotherapy with modafinil who developed symptoms of tolerance were eligible. The following alternating therapy regimen was established: Monday to Friday patients continued on modafinil whereas Saturday and Sunday they switched to pitolisant to "bridge" the EDS symptoms. Patients were assessed at baseline and after three months with the Epworth Sleepiness Scale (ESS) and the Ullanlinna Narcolepsy Scale (UNS). Health-related quality of life (HrQol) was evaluated by EuroQol5D. Adverse events were documented in the patients' diaries.

RESULTS

41 patients aged 30.9 ± 5.6 years were included. After three months of the alternating therapy regimen, the symptoms of tolerance decreased and the modafinil dose could be reduced by 41% (p < 0.01) resulting in better safety. The EDS improved on ESS (baseline: 18.2 ± 4.2, follow-up: 12.6 ± 4.0, p < 0.0001) and UNS (baseline: 25.8 ± 7.9, follow-up: 18.9 ± 5.9, p < 0.0001). The HrQol increased significantly.

CONCLUSION

Patients with tolerance to modafinil could benefit from pitolisant-supported bridging during drug holidays. This alternating pharmacological strategy proved to be safe and helped to reduce EDS and to decrease the modafinil dose. Further randomized controlled studies are required to evaluate the different strategies to deal with the tolerance to modafinil.

CLINICAL TRIAL REGISTRATION NUMBER

Clinical Trials.gov Identifier NCT05321355.

Cardiovascular Burden of Narcolepsy Disease (CV-BOND): a real-world evidence study

STUDY OBJECTIVES

Narcolepsy is associated with cardiovascular risk factors; however, the risk of new-onset cardiovascular events in this population is unknown. This real-world study evaluated the excess risk of new-onset cardiovascular events in U.S. adults with narcolepsy.

METHODS

A retrospective cohort study using IBM MarketScan administrative claims data (2014-2019) was conducted. A narcolepsy cohort, comprising adults (≥18 years) with at least two outpatient claims containing a narcolepsy diagnosis, of which at least one was non-diagnostic, was matched to a non-narcolepsy control cohort (1:3) based on cohort entry date, age, sex, geographic region, and insurance type. The relative risk of new-onset cardiovascular events was estimated using a multivariable Cox proportional hazards model to compute adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The narcolepsy and matched non-narcolepsy control cohorts included 12 816 and 38 441 individuals, respectively. At baseline, cohort demographics were generally similar; however, patients with narcolepsy had more comorbidities. In adjusted analyses, the risk of new-onset cardiovascular events was higher in the narcolepsy cohort compared with the control cohort: any stroke (HR [95% CI], 1.71 [1.24, 2.34]); heart failure (1.35 [1.03, 1.76]); ischemic stroke (1.67 [1.19, 2.34]); major adverse cardiac event (1.45 [1.20, 1.74]); grouped instances of stroke, atrial fibrillation, or edema (1.48 [1.25, 1.74]); and cardiovascular disease (1.30 [1.08, 1.56]).

CONCLUSION

Individuals with narcolepsy are at increased risk of new-onset cardiovascular events compared with individuals without narcolepsy. Physicians should consider cardiovascular risk in patients with narcolepsy when weighing treatment options.

Evaluation of the efficacy of the hypocretin/orexin receptor agonists TAK-925 and ARN-776 in narcoleptic orexin/tTA; TetO-DTA mice

The sleep disorder narcolepsy, a hypocretin deficiency disorder thought to be due to degeneration of hypothalamic hypocretin/orexin neurons, is currently treated symptomatically. We evaluated the efficacy of two small molecule hypocretin/orexin receptor-2 (HCRTR2) agonists in narcoleptic male orexin/tTA; TetO-DTA mice. TAK-925 (1-10 mg/kg, s.c.) and ARN-776 (1-10 mg/kg, i.p.) were injected 15 min before dark onset in a repeated measures design. EEG, EMG, subcutaneous temperature (Tsc ) and activity were recorded by telemetry; recordings for the first 6 h of the dark period were scored for sleep/wake and cataplexy. At all doses tested, TAK-925 and ARN-776 caused continuous wakefulness and eliminated sleep for the first hour. Both TAK-925 and ARN-776 caused dose-related delays in NREM sleep onset. All doses of TAK-925 and all but the lowest dose of ARN-776 eliminated cataplexy during the first hour after treatment; the anti-cataplectic effect of TAK-925 persisted into the second hour for the highest dose. TAK-925 and ARN-776 also reduced the cumulative amount of cataplexy during the 6 h post-dosing period. The acute increase in wakefulness produced by both HCRTR2 agonists was characterised by increased spectral power in the gamma EEG band. Although neither compound provoked a NREM sleep rebound, both compounds affected NREM EEG during the second hour post-dosing. TAK-925 and ARN-776 also increased gross motor activity, running wheel activity, and Tsc , suggesting that the wake-promoting and sleep-suppressing activities of these compounds could be a consequence of hyperactivity. Nonetheless, the anti-cataplectic activity of TAK-925 and ARN-776 is encouraging for the development of HCRTR2 agonists.

Clinician Preferences for Oxybate Treatment for Narcolepsy: Survey and Discrete Choice Experiment

INTRODUCTION

Immediate-release sodium oxybate (SXB) has been Food and Drug Administration (FDA)-approved to treat narcolepsy since 2002; in 2020, a mixed-salt oxybates formulation was also approved. Both are taken at bedtime with a second dose taken 2.5-4 h later. A third oxybate option, an investigational extended-release SXB, may soon be available. This study was undertaken to understand clinicians' preferences between these 3 different oxybate treatments.

METHODS

Clinicians in active clinical practice for 3-35 years and experience treating patients with narcolepsy were recruited. A 30-min web-based survey quantified narcolepsy disease-state attitudes, treatment perceptions, and satisfaction with oxybates on 9-point scales. A discrete choice experiment (DCE) of 12 choice sets, with 2 hypothetical treatment profiles in each, was used to capture clinician preferences about overall oxybate therapy preference, impact on patient quality of life (QoL), and patient anxiety/stress. Attributes associated with current therapies and those expected to be available in the near future were included in the design.

RESULTS

The clinicians surveyed (n = 100) indicated that narcolepsy has a negative impact on patient QoL (mean rating, 7.7) and rated impact on QoL and treatment efficacy as the most important aspects of a narcolepsy treatment (mean rating, 7.3-7.7). Clinicians with experience prescribing oxybates had moderately high satisfaction with SXB and mixed-salt oxybates efficacy (mean ratings, 6.5-6.9) and safety (mean ratings, 6.1-6.7) and lower satisfaction with nightly dosing frequency (mean rating, 5.9 and 6.3, respectively). In the DCE, dosing frequency was the most important attribute driving overall product choice, patient QoL, and reducing patient anxiety/stress (relative attribute importance, 46.1, 41.7, and 44.0, respectively), with once nightly preferred over twice nightly.

CONCLUSION

Clinicians indicated a significantly higher preference for the once-at-bedtime dosing schedule versus twice nightly in selecting oxybate therapies overall and when aiming to improve patient QoL or reduce patient anxiety.

Solriamfetol improves chronic sleep fragmentation-induced increases in sleep propensity and ameliorates explicit memory in male mice

Obstructive sleep apnea (OSA) is a highly prevalent condition characterized by episodes of partial or complete breath cessation during sleep that induces sleep fragmentation (SF). One of the frequent manifestations of OSA is the presence of excessive daytime sleepiness (EDS) associated with cognitive deficits. Solriamfetol (SOL) and modafinil (MOD) are wake-promoting agents commonly prescribed to improve wakefulness in OSA patients with EDS. This study aimed to assess the effects of SOL and MOD in a murine model of OSA characterized by periodic SF. Male C57Bl/6J mice were exposed to either control sleep (SC) or SF (mimicking OSA) during the light period (06:00 h to 18:00 h) for 4 weeks, which consistently induces sustained excessive sleepiness during the dark phase. Both groups were then randomly assigned to receive once-daily intraperitoneal injections of SOL (200 mg/kg), MOD (200 mg/kg), or vehicle for 1 week while continuing exposures to SF or SC. Sleep/wake activity and sleep propensity were assessed during the dark phase. Novel Object Recognition test, Elevated-Plus Maze Test, and Forced Swim Test were performed before and after treatment. SOL or MOD decreased sleep propensity in SF, but only SOL induced improvements in explicit memory, while MOD exhibited increased anxiety behaviors. Chronic SF, a major hallmark of OSA, induces EDS in young adult mice that is mitigated by both SOL and MOD. SOL, but not MOD, significantly improves SF-induced cognitive deficits. Increased anxiety behaviors are apparent in MOD-treated mice. Further studies aiming to elucidate the beneficial cognitive effects of SOL are warranted.

A multicenter, double-blind, placebo-controlled, randomized, Phase 1b crossover trial comparing two doses of ulotaront with placebo in the treatment of narcolepsy-cataplexy

BACKGROUND

Ulotaront (SEP-363856) is a novel agonist at trace amine-associated receptor 1 and serotonin 5-HT_1A receptors in clinical development for the treatment of schizophrenia. Previous studies demonstrated ulotaront suppresses rapid eye movement (REM) sleep in both rodents and healthy volunteers. We assessed acute and sustained treatments of ulotaront on REM sleep and symptoms of cataplexy and alertness in subjects with narcolepsy-cataplexy.

METHODS

In a multicenter, double-blind, placebo-controlled, randomized, 3-way crossover study, ulotaront was evaluated in 16 adults with narcolepsy-cataplexy. Two oral doses of ulotaront (25 mg and 50 mg) were administered daily for 2 weeks and compared with matching placebo (6-treatment sequence, 3-period, 3-treatment).

RESULTS

Acute treatment with both 25 mg and 50 mg of ulotaront reduced minutes spent in nighttime REM compared to placebo. A sustained 2-week administration of both doses of ulotaront reduced the mean number of short-onset REM periods (SOREMPs) during daytime multiple sleep latency test (MSLT) compared to placebo. Although cataplexy events decreased from the overall mean baseline during the 2-week treatment period, neither dose of ulotaront statistically separated from placebo (p = 0.76, 25 mg; p = 0.82, 50 mg), and no significant improvement in patient and clinician measures of sleepiness from baseline to end of the 2-week treatment period occurred in any treatment group.

CONCLUSIONS

Acute and sustained treatment with ulotaront reduced nighttime REM duration and daytime SOREMPs, respectively. The effect of ulotaront on suppression of REM did not demonstrate a statistical or clinically meaningful effect in narcolepsy-cataplexy.

REGISTRATION

ClinicalTrials.gov identifier: NCT05015673.

Solriamfetol real world experience study (SURWEY): Initiation, titration, safety, effectiveness, and experience during follow-up for patients with narcolepsy from Germany

BACKGROUND

Excessive daytime sleepiness (EDS) is a core narcolepsy symptom, for which solriamfetol (Sunosi®) was recently approved in the European Union. SURWEY characterises real-world strategies used by physicians when initiating solriamfetol, and patient outcomes after follow-up.

METHODS

SURWEY is an ongoing retrospective chart review conducted by physicians in Germany/France/Italy. Here, data are reported from 70 German patients with EDS and narcolepsy. Eligibility included age ≥18 years, reached a stable solriamfetol dose, and completed ≥6 weeks of treatment. Patients were classified (based on existing EDS treatment) into changeover, add-on, or new-to-therapy subgroups.

RESULTS

Patients' mean ± SD age was 36.9 ± 13.9 years. Changeover from prior EDS medication was the most common initiation strategy. Initial solriamfetol dose was typically 75 mg/day (69%). In 30 patients (43%), solriamfetol was titrated; 27/30 (90%) completed titration as prescribed, most within 7 days. Mean ± SD Epworth Sleepiness Scale (ESS) score was 17.6 ± 3.1 at initiation (n = 61) and 13.6 ± 3.8 at follow-up (n = 51). Slight/strong improvements in EDS were perceived for >90% of patients (patient and physician report). Sixty-two percent reported an effect duration of 6 to <10 h; 72% reported no change in perceived nighttime sleep quality. Common adverse events included headache (9%), decreased appetite (6%), and insomnia (6%); no cardiovascular events were reported.

CONCLUSIONS

Most patients in this study were switched from a prior EDS medication to solriamfetol. Solriamfetol was typically initiated at 75 mg/day; titration was common. ESS scores improved after initiation, and most patients perceived improvement in EDS. Common adverse events were consistent with those reported in clinical trials.

CLINICALTRIALS

GOV REGISTRATION

N/A.

Comparative Efficacy and Safety of Multiple Wake-Promoting Agents for the Treatment of Excessive Daytime Sleepiness in Narcolepsy: A Network Meta-Analysis

Purpose

Narcolepsy is a rare debilitating disorder for which multiple novel pharmacological options have been approved as treatment for the past few years. The current study systematically updates the comparative efficacy and detailed safety analysis of approved wake-promoting agents in narcolepsy.

Methods

Randomized controlled trials (RCTs) were searched for diagnosed narcolepsy with approved interventions. Efficacy outcomes included the Maintenance of Wakefulness Test (MWT), Epworth Sleepiness Scale (ESS), Clinical Global Impression of Change (CGI-C), and Patient Global Impression of Change (PGI-C). Safety outcomes including overall adverse event (AE) risk were measured. The study was registered at PROSPERO (CRD 42022334915).

Results

The final analysis included 17 RCTs with five drug treatments: modafinil/armodafinil, sodium oxybate, pitolisant, solriamfetol, and lower-sodium oxybate (LXB). For efficacy measures, interventions included in each outcome were effective compared with placebo. Furthermore, the magnitude of solriamfetol effect on MWT (9.11 minutes; 95% CI=7.05-11.16), ESS (-4.79; 95% CI=-6.56 to -3.01), and PGI-C (9.39; 95% CI= 2.37-37.19), and LXB effect on CGI-C (9.67; 95% CI=2.73-34.26) was greater than that of other treatments included in each outcome compared with placebo. For safety measures, all interventions had an acceptable safety profile with LXB having least risk for overall AEs (0.56; 95% CI=0.20-1.53), serious AEs (0.33; 95% CI=0.09-1.20), AEs leading to treatment discontinuation (0.11; 95% CI=0.01-2.04), and all-cause discontinuation (0.04; 95% CI=0.00-0.67) compared to placebo. Placebo had the lowest risk for exploratory AEs.

Conclusion

All approved interventions were effective in controlling the symptoms of narcolepsy at varying degrees with an acceptable safety profile.

Solriamfetol treatment of excessive daytime sleepiness in participants with narcolepsy or obstructive sleep apnea with a history of depression

Given the high rate of depression associated with narcolepsy or obstructive sleep apnea (OSA), this analysis compared effects of solriamfetol treatment of excessive daytime sleepiness (EDS) in participants with/without a history of depression (DHx+/DHx-). This secondary analysis included data from two randomized, controlled trials in which participants were randomized to 12 weeks placebo or solriamfetol 37.5 (OSA only), 75, 150, or 300 mg/day. Efficacy/safety (combined solriamfetol doses) was summarized for DHx+/DHx-subgroups. 27.5% (65/236) with narcolepsy and 23.4% (111/474) with OSA were DHx+. In narcolepsy (DHx+ and DHx-), 40-min Maintenance of Wakefulness Test (MWT40) mean sleep latency increased (5.4 and 7.0 min), Epworth Sleepiness Scale (ESS) score decreased (3.8 and 3.5 points), and percentage of participants improved on Patient Global Impression of Change (PGI-C) was higher (31.7% and 39.4%) relative to placebo. In OSA (DHx+ and DHx-), MWT40 mean sleep latency increased (7.7 and 10.7 min), ESS decreased (3.5 and 3.7 points), and percentage of participants improved on PGI-C was higher (41.1% and 29.4%) relative to placebo. Common treatment-emergent adverse events (headache, decreased appetite, nausea, anxiety) were similar in DHx+/DHx-. This study suggests that safety and efficacy of solriamfetol for treating EDS in narcolepsy and OSA are not affected by depression history. Moreover, the findings emphasize the high prevalence of depression in people with sleep disorders and suggest that increased awareness of this association may have clinical significance.

Solriamfetol Titration & AdministRaTion (START) in Patients With Narcolepsy

PURPOSE

Solriamfetol, a dopamine/norepinephrine reuptake inhibitor, is approved (in the United States and European Union) to treat excessive daytime sleepiness (EDS) in adults with narcolepsy (75-150 mg/d) or obstructive sleep apnea (OSA) (37.5-150 mg/d). This study characterized real-world titration strategies for patients with narcolepsy (with or without comorbid OSA) initiating solriamfetol therapy.

METHODS

This virtual, descriptive study included a retrospective medical record review and qualitative survey. US-based physicians prescribing solriamfetol for EDS associated with narcolepsy or OSA participated. Data are reported for patients with narcolepsy with or without comorbid OSA (OSA alone reported separately). On the basis of medical record review, titration strategies were classified de novo (EDS medication naive), transition (switched or switching from existing EDS medication[s] to solriamfetol), or add-on (adding solriamfetol to current EDS medication[s]). The survey included open-ended questions regarding a hypothetical patient-a 32-year-old woman with narcolepsy (Epworth Sleepiness Scale score of 8) treated with 35 mg/d of amphetamine and 6 g per night of sodium oxybate who experiences non-use-limiting adverse events from amphetamine.

FINDINGS

Twenty-six physicians participated: 23 provided data from 70 patients with narcolepsy (type 1, n = 24; type 2, n = 46; mean [SD] age, 40 [11] years; 57% female; 6 with comorbid OSA), and 26 responded to the hypothetical patient scenario. From the medical record review, solriamfetol therapy initiation was de novo for 19 of 70 patients (27%), transition for 31 of 70 patients (44%), and add-on for 20 of 70 patients (29%). Efficacy profile of solriamfetol was the primary reason for de novo (12 of 19 [63%]), transition (18 of 31 [58%]), and add-on (19 of 20 [95%]) initiation. Most (86%) initiated use of solriamfetol at 75 mg/d and were stable at 150 mg/d (76%). Most (67%) had 1 dose adjustment, reaching a stable dose over a median (range) of 14 (1-60) days. Physicians most often considered EDS severity (44%) when titrating. Among transitioning patients, 14 of 22 (64%) using wake-promoting agents discontinued their use abruptly, and 5 of 9 (56%) using stimulants were tapered off. At data collection, 90% continued to take solriamfetol. Regarding the hypothetical patient scenario, most physicians (81%) thought solriamfetol was appropriate, highlighting tolerability issues with current treatment and lack of symptom control as drivers for switching; however, 3 physicians (12%) did not think solriamfetol was appropriate, noting current symptoms were not severe enough and/or symptoms could be managed by increasing sodium oxybate dose; 2 (8%) thought it would depend on other factors. Physicians emphasized managing withdrawal symptoms while maintaining EDS symptom control when titrating off a stimulant and starting solriamfetol therapy.

IMPLICATIONS

In a real-world study, physicians initiated solriamfetol therapy at 75 mg/d for most patients with narcolepsy, adjusted dosages once, tapered stimulants, and abruptly discontinued therapy with wake-promoting agents. (Clin Ther. 2022;XX:XXX-XXX) © 2022 Elsevier HS Journals, Inc.

Danavorexton, a selective orexin 2 receptor agonist, provides a symptomatic improvement in a narcolepsy mouse model

Narcolepsy type 1 (NT1), caused by loss of orexin neurons, is a neurological disorder characterized by excessive daytime sleepiness, cataplexy, disrupted nighttime sleep, hypnagogic/hypnopompic hallucinations and sleep paralysis, as well as a high risk of obesity. Danavorexton (TAK-925) is a novel brain-penetrant orexin 2 receptor (OX2R)-selective agonist currently being evaluated in clinical trials for the treatment of hypersomnia disorders including NT1. Thus, detailed characterization of danavorexton is critical for validating therapeutic potential of OX2R-selective agonists. Here, we report preclinical characteristics of danavorexton as a therapeutic drug for NT1. Danavorexton showed rapid association/dissociation kinetics to OX2R. The activation mode of endogenous OX2R by danavorexton and orexin peptide was very similar in an electrophysiological analysis. In orexin/ataxin-3 mice, a mouse model of NT1, danavorexton promoted wakefulness, and ameliorated fragmentation of wakefulness during the active phase after both acute and repeated administration, suggesting a low risk of receptor desensitization. Electroencephalogram (EEG) power spectral analysis revealed that danavorexton, but not modafinil, normalized dysregulated EEG power spectrum in orexin/ataxin-3 mice during the active phase. Finally, repeated administration of danavorexton significantly suppressed the body weight gain in orexin/ataxin-3 mice. Danavorexton may have the potential to treat multiple symptoms of NT1. These preclinical findings, together with upcoming clinical observations of danavorexton, could improve our understanding of the pathophysiology of NT1 and therapeutic potential of OX2R agonists.

What respiratory physicians should know about narcolepsy and other hypersomnias

Narcolepsy and related central disorders of hypersomnolence may present to the sleep clinic with excessive daytime sleepiness. A strong clinical suspicion and awareness of the diagnostic clues, such as cataplexy, are essential to avoid unnecessary diagnostic delay. This review provides an overview of the epidemiology, pathophysiology, clinical features, diagnostic criteria and management of narcolepsy and related disorders, including idiopathic hypersomnia, Kleine-Levin syndrome (recurrent episodic hypersomnia) and secondary central disorders of hypersomnolence.

Orexin 2 receptor-selective agonist danavorexton improves narcolepsy phenotype in a mouse model and in human patients

Narcolepsy type 1 (NT1) is a sleep disorder caused by a loss of orexinergic neurons. Narcolepsy type 2 (NT2) is heterogeneous; affected individuals typically have normal orexin levels. Following evaluation in mice, the effects of the orexin 2 receptor (OX2R)-selective agonist danavorexton were evaluated in single- and multiple-rising-dose studies in healthy adults, and in individuals with NT1 and NT2. In orexin/ataxin-3 narcolepsy mice, danavorexton reduced sleep/wakefulness fragmentation and cataplexy-like episodes during the active phase. In humans, danavorexton administered intravenously was well tolerated and was associated with marked improvements in sleep latency in both NT1 and NT2. In individuals with NT1, danavorexton dose-dependently increased sleep latency in the Maintenance of Wakefulness Test, up to the ceiling effect of 40 min, in both the single- and multiple-rising-dose studies. These findings indicate that OX2Rs remain functional despite long-term orexin loss in NT1. OX2R-selective agonists are a promising treatment for both NT1 and NT2.

Evaluation of psychometric properties of patient-reported outcome measures frequently used in narcolepsy randomized controlled trials: a systematic review

Study Objectives

To systematically determine subjective and objective outcome measures used to measure the efficacy of narcolepsy interventions in randomized controlled trials (RCTs) in adults and children and assess psychometric properties of patient-reported outcome measures (PROMs) used.

Methods

We searched bibliographical databases and clinical trial registries for narcolepsy RCTs and extracted objective and subjective outcome measures. If PROMs were used, we searched for psychometric studies conducted in a narcolepsy population using bibliographical databases and appraised using Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines.

Results

In total, 80 different outcome measures were used across 100 RCTs. Epworth Sleepiness Scale (ESS) (n = 49) and Maintenance of Wakefulness Test (n = 47) were the most frequently used outcome measures. We found 19 validation studies of 10 PROMs in narcolepsy populations. There was limited evidence for validity or responsiveness of the ESS; yet sufficient reliability (pooled ICC: 0.81–0.87). Narcolepsy Severity Scale (NSS) had sufficient reliability (pooled ICC: 0.71–0.92) and both adult and pediatric versions had sufficient discriminant validity (treated/untreated). Content validity was only evaluated in pediatric populations for ESS-CHAD and NSS-P and rated inconclusive. Quality of evidence of the psychometric studies for all scales ranged from very low to low.

Conclusions

Although recognized by regulatory bodies and widely used as primary outcome measures in trials, there is surprisingly little evidence for the validity, reliability, and responsiveness of PROMs frequently used to assess treatment efficacy in narcolepsy. The field needs to establish patient-centered minimal clinically important differences for the PROMs used in these trials.

Once-nightly sodium oxybate (FT218) demonstrated improvement of symptoms in a phase 3 randomized clinical trial in patients with narcolepsy

STUDY OBJECTIVES

To assess the efficacy and safety of FT218, a novel once-nightly formulation of sodium oxybate (ON-SXB), in patients with narcolepsy in the phase 3 REST-ON trial.

METHODS

Narcolepsy patients aged ≥16 years were randomized 1:1 to uptitration of ON-SXB (4.5, 6, 7.5, and 9 g) or placebo. Three coprimary endpoints were change from baseline in mean sleep latency on the Maintenance of Wakefulness Test, Clinical Global Impression-Improvement rating, and weekly cataplexy attacks at 9, 7.5, and 6 g. Secondary endpoints included change from baseline on the Epworth Sleepiness Scale. Safety included adverse drug reactions and clinical laboratory assessments.

RESULTS

In total, 222 patients were randomized; 212 received ≥1 dose of ON-SXB (n = 107) or placebo (n = 105). For the three coprimary endpoints and Epworth Sleepiness Scale, all three doses of ON-SXB demonstrated clinically meaningful, statistically significant improvement versus placebo (all p < 0.001). For ON-SXB 9 g versus placebo, increase in mean sleep latency was 10.8 versus 4.7 min (Least squares mean difference, LSMD [95% CI], 6.13 [3.52 to 8.75]), 72.0% versus 31.6% were rated much/very much improved on Clinical Global Impression-Improvement (OR [95% CI], 5.56 [2.76 to 11.23]), change in mean weekly number of cataplexy attacks was -11.5 versus -4.9 (LSMD [95% CI], -6.65 [-9.32 to -3.98]), and change in Epworth Sleepiness Scale was -6.5 and -2.7 (LSMD [95% CI], -6.52 [-5.47 to -2.26]). Common adverse reactions included nausea, vomiting, headache, dizziness, and enuresis.

CONCLUSIONS

ON-SXB significantly improved narcolepsy symptoms; its safety profile was consistent with SXB. ON-SXB conferred efficacy with a clearly beneficial single nighttime dose.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02720744, https://clinicaltrials.gov/ct2/show/NCT02720744.

pitolisant, a novel histamine-3 receptor competitive antagonist, and inverse agonist, in the treatment of excessive daytime sleepiness in adult patients with narcolepsy

Narcolepsy is a debilitating sleep disorder that presents with excessive daytime sleepiness (EDS) and cataplexy, which is a sudden paralysis of muscle tone triggered by strong emotions such as laughing. It is also associated with many other disorders, including psychiatric disorders, neurologic illnesses, and medication side effects. Common causes of delayed and incorrect diagnoses of these conditions include lack of physician familiarity with narcolepsy symptoms and comorbidities which mask narcolepsy signs and symptoms. Current pharmacologic therapies include Modafinil and Armodafinil for EDS and sodium oxybate for cataplexy. This review discusses the epidemiology, pathophysiology, risk factors, presentation, treatment of narcolepsy, and the role of a novel drug, Pitolisant, in the treatment of EDS in adults with narcolepsy. Pitolisant is a histamine-3 receptor (H3R), competitive antagonist, and inverse agonist, acting through the histamine system to regulate wakefulness. It is a novel drug approved in August 2019 by the FDA, is not classified as a controlled substance, and is approved for use in Europe and the United States to treat EDS and cataplexy in narcolepsy. Recent phase II and III trials have shown that Pitolisant helps reduce the ESS score and cataplexy. In summary, based on comparative studies, recent evidence has shown that Pitolisant is non-inferior to Modafinil in the treatment of EDS but superior to Modafinil in reducing cataplexy.

Solriamfetol for the Use of Narcolepsy: A Systematic Review

Narcolepsy is a chronic and disabling neurological disorder characterized by excessive daytime sleepiness (EDS) and cataplexy. Historically, some medications have demonstrated efficacy in managing EDS and cataplexy symptoms. However, some patients cannot tolerate them, become refractory, or may use concomitant medications that preclude the use due to drug-drug interaction. Therefore, there is a necessity to explore the efficacy of new treatments, such as solriamfetol (JZP-110), a 2019 FDA-approved drug indicated to improve wakefulness in adults with EDS associated with narcolepsy.

We conducted this systematic review to investigate the effectiveness of solriamfetol in EDS and cataplexy, and the drug's overall safety. For this study, we used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and MOOSE protocol. After an initial search of 119 papers, we included four clinical trials to investigate and analyze the use of solriamfetol for the treatment of narcolepsy.

Solriamfetol was proven to improve objective measures of EDS in all clinical trials. We conducted this systematic review using objective measures such as the Epworth Sleepiness Scale and the Maintenance of Wakefulness Test. Overall, cataplexy was not formally evaluated in the four clinical trials; however, it demonstrated that EDS improved in patients with and without cataplexy. More clinical trials are needed to analyze the efficacy of solriamfetol on cataplexy. The effect of solriamfetol in EDS seems to be conclusive.

The development of sleep/wake disruption and cataplexy as hypocretin/orexin neurons degenerate in male vs. female Orexin/tTA; TetO-DTA Mice

Narcolepsy Type 1 (NT1), a sleep disorder with similar prevalence in both sexes, is thought to be due to loss of the hypocretin/orexin (Hcrt) neurons. Several transgenic strains have been created to model this disorder and are increasingly being used for preclinical drug development and basic science studies, yet most studies have solely used male mice. We compared the development of narcoleptic symptomatology in male vs. female orexin-tTA; TetO-DTA mice, a model in which Hcrt neuron degeneration can be initiated by removal of doxycycline (DOX) from the diet. EEG, EMG, subcutaneous temperature, gross motor activity, and video recordings were conducted for 24-h at baseline and 1, 2, 4, and 6 weeks after DOX removal. Female DTA mice exhibited cataplexy, the pathognomonic symptom of NT1, by Week 1 in the DOX(-) condition but cataplexy was not consistently present in males until Week 2. By Week 2, both sexes showed an impaired ability to sustain long wake bouts during the active period, the murine equivalent of excessive daytime sleepiness in NT1. Subcutaneous temperature appeared to be regulated at lower levels in both sexes as the Hcrt neurons degenerated. During degeneration, both sexes also exhibited the "Delta State", characterized by sudden cessation of activity, high delta activity in the EEG, maintenance of muscle tone and posture, and the absence of phasic EMG activity. Since the phenotypes of the two sexes were indistinguishable by Week 6, we conclude that both sexes can be safely combined in future studies to reduce cost and animal use.

Photocatalytic defluoroalkylation and hydrodefluorination of trifluoromethyls using o-phosphinophenolate

Under visible light irradiation, o-phosphinophenolate functions as an easily accessible photoredox catalyst to activate trifluoromethyl groups in trifluoroacetamides, trifluoroacetates, and trifluoromethyl (hetero)arenes to deliver corresponding difluoromethyl radicals. It works in relay with a thiol hydrogen atom transfer (HAT) catalyst to enable selective defluoroalkylation and hydrodefluorination. The reaction allows for the facile synthesis of a broad scope of difluoromethylene-incorporated carbonyl and (hetero)aromatic compounds, which are valuable fluorinated intermediates of interest in the pharmaceutical industry. The ortho-diphenylphosphino substituent, which is believed to facilitate photoinduced electron transfer, plays an essential role in the redox reactivity of phenolate. In addition to trifluoromethyl groups, pentafluoroethyl groups could also be selectively defluoroalkylated.

Photoredox catalysis can strongly reduce and cleave unactivated chemical bonds via photoinduced electron transfer. Here the authors use o-phosphinophenolate for photocatalytic C–F activation of a wide range of trifluoromethyl groups in trifluoroacetamides, trifluoroacetates, and trifluoromethyl(hetero)arenes to deliver corresponding difluoromethyl radicals.

Current Understanding of Narcolepsy 1 and its Comorbidities: What Clinicians Need to Know

Narcolepsy is a chronic neurologic disorder associated with the dysregulation of the sleep–wake cycle that often leads to a decreased quality of life and results in a considerable health burden. There is often a delay to diagnosis of narcolepsy, mainly due to the lack of recognition of this disorder. One of the main factors hindering the diagnosis of narcolepsy is the association of comorbidities, which include other sleep disorders, psychiatric disorders, cardiovascular disorders, and metabolic disorders. The signs and symptoms of these comorbidities often overlap with those of narcolepsy, and some of the medications used for their treatment may obscure the symptoms of narcolepsy, leading to a delay in diagnosis. This review is targeted to clinicians unaccustomed to working with sleep disorders and aims to increase recognition and improve the management of narcolepsy.

The Orexin receptors: Structural and anti-tumoral properties

At the end of the 20th century, two new neuropeptides (Orexin-A/hypocretin-1 and Orexin-B/hypocretins-2) expressed in hypothalamus as a prepro-orexins precursor, were discovered. These two neuropeptides interacted with two G protein-coupled receptor isoforms named OX1R and OX2R. The orexins/OX receptors system play an important role in the central and peripheral nervous system where it controls wakefulness, addiction, reward seeking, stress, motivation, memory, energy homeostasis, food intake, blood pressure, hormone secretions, reproduction, gut motility and lipolysis. Orexins and their receptors are involved in pathologies including narcolepsy type I, neuro- and chronic inflammation, neurodegenerative diseases, metabolic syndrome, and cancers. Associated with these physiopathological roles, the extensive development of pharmacological molecules including OXR antagonists, has emerged in association with the determination of the structural properties of orexins and their receptors. Moreover, the identification of OX1R expression in digestive cancers encompassing colon, pancreas and liver cancers and its ability to trigger mitochondrial apoptosis in tumoral cells, indicate a new putative therapeutical action of orexins and paradoxically OXR antagonists. The present review focuses on structural and anti-tumoral aspects of orexins and their receptors.

Calcium, Magnesium, Potassium and Sodium Oxybates (Xywav®) in Sleep Disorders: A Profile of Its Use

Calcium, magnesium, potassium and sodium oxybates (Xywav^®; hereafter referred to as lower-sodium oxybate), a new oxybate formulation with a greatly reduced sodium burden compared with previously approved sodium oxybate (Xyrem^®), is approved for the treatment of cataplexy and excessive daytime sleepiness (EDS) in adults and children aged ≥ 7 years with narcolepsy, and is the first drug approved for the treatment of idiopathic hypersomnia in adults in the USA. In two pivotal, double-blind, placebo-controlled, phase 3 trials of randomized-withdrawal design, lower-sodium oxybate effectively improved cataplexy and EDS in adults with narcolepsy, and EDS and overall idiopathic hypersomnia symptoms in adults with idiopathic hypersomnia during open-label titration and optimization periods. At the end of the double-blind, randomized withdrawal period, participants randomized to switch to placebo experienced significant worsening in these symptoms compared with those randomized to continue lower-sodium oxybate. Furthermore, worsening in patient- and clinical-rated global scales, as well as measures of health-related quality of life were also seen with placebo versus lower-sodium oxybate. Lower-sodium oxybate is generally well tolerated, with the tolerability profile being largely consistent to that seen with sodium oxybate.

Clinical Impact of Pitolisant on Excessive Daytime Sleepiness and Cataplexy in Adults With Narcolepsy: An Analysis of Randomized Placebo-Controlled Trials

BACKGROUND

Pitolisant, a selective histamine 3 receptor antagonist/inverse agonist, is indicated for the treatment of excessive daytime sleepiness or cataplexy in adults with narcolepsy. The efficacy and safety of pitolisant have been demonstrated in randomized placebo-controlled trials. When evaluating the results of randomized placebo-controlled trials, the clinical impact of a treatment can be assessed using effect size metrics that include Cohen's d (the standardized mean difference of an effect) and number needed to treat (NNT; number of patients that need to be treated to achieve a specific outcome for one person).

OBJECTIVE

The objective of this study was to evaluate the clinical impact of pitolisant for the reduction in excessive daytime sleepiness or cataplexy in adults with narcolepsy.

METHODS

This post hoc analysis incorporated data from two 7-week or 8-week randomized placebo-controlled trials (HARMONY 1, HARMONY CTP). Study medication was individually titrated, with a maximum possible pitolisant dose of 35.6 mg/day. Efficacy was assessed using the Epworth Sleepiness Scale (ESS) and weekly rate of cataplexy (HARMONY CTP only). Cohen's d was derived from the least-squares mean difference between treatment groups (pitolisant vs placebo), and NNTs were calculated from response rates. Treatment response was defined for excessive daytime sleepiness in two ways: (a) reduction in ESS score ≥ 3 or final ESS score ≤ 10 and (b) final ESS score ≤ 10. Treatment response was defined for cataplexy as a ≥ 25%, ≥ 50%, or ≥ 75% reduction in weekly rate of cataplexy.

RESULTS

The analysis population included 61 patients in HARMONY 1 (pitolisant, n = 31; placebo, n = 30) and 105 patients in HARMONY CTP (pitolisant, n = 54; placebo, n = 51). For pitolisant vs placebo, Cohen's d effect size values were 0.61 (HARMONY 1) and 0.86 (HARMONY CTP) based on changes in ESS scores, and 0.86 (HARMONY CTP) based on changes in weekly rate of cataplexy. NNTs for pitolisant were 3-5 for the treatment of excessive daytime sleepiness and 3-4 for the treatment of cataplexy.

CONCLUSIONS

The results of this analysis demonstrate the robust efficacy of pitolisant for the reduction in both excessive daytime sleepiness and cataplexy. These large effect sizes and low NNTs provide further evidence supporting the strength of the clinical response to pitolisant in the treatment of adults with narcolepsy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT01067222 (February 2010), NCT01800045 (February 2013).

Preferences for Attributes of Sodium Oxybate Treatment: A Discrete Choice Experiment in Patients with Narcolepsy

PURPOSE

Current US FDA-approved treatments for narcolepsy include sodium oxybate (SXB) and calcium, magnesium, potassium, and sodium oxybates (mixed-salt oxybates), which require 2 nightly doses, 1 at bedtime and another 2.5 to 4 hours later. Once-nightly SXB (ON-SXB; FT218) is under FDA review to treat adults with narcolepsy. This study quantitatively characterized attributes of SXB treatment preferred by individuals with narcolepsy via a discrete choice experiment (DCE) and evaluated preferences for the product profiles of once-nightly vs twice-nightly SXB treatment.

PATIENTS AND METHODS

Adults with self-reported physician-diagnosed narcolepsy for ≥1 year and current or prior twice-nightly SXB treatment were eligible for this 30-minute, web-based study capturing patient experiences and a DCE. Participants responded to a survey instrument using 9-point scales; higher scores indicated greater severity/preference/satisfaction. In the DCE, hundreds of profiles were generated, each combining attributes of twice-nightly SXB and ON-SXB based on clinical trial data. The DCE was analyzed using a hierarchical Bayesian model.

RESULTS

Seventy-five participants were surveyed (50 current and 25 past twice-nightly SXB users). Dosing frequency was the most important attribute of SXB treatment; once nightly was significantly preferred vs twice nightly. The most common reasons for overall product preference were lack of need to wake up in the middle of the night for a second dose (48%), fewer side effects (46%), and ease of administration (32%). Number of nightly doses was the most important driver of taking the medication exactly as directed and reduced anxiety/stress. Participants were significantly more likely to prefer the blinded product profile of once-nightly SXB over twice-nightly SXB (mean rating, 7.5 vs 4.3; P<0.05).

CONCLUSION

Among the choices presented, dosing frequency was the most important attribute for overall product choice, likelihood to take medication exactly as directed, and reducing anxiety/stress. The ON-SXB blinded profile was significantly preferred over twice-nightly SXB.

Effect of FT218, a Once-Nightly Sodium Oxybate Formulation, on Disrupted Nighttime Sleep in Patients with Narcolepsy: Results from the Randomized Phase III REST-ON Trial

BACKGROUND

Sodium oxybate has been recognized as a gold standard for the treatment of disrupted nighttime sleep due to narcolepsy. Its short half-life and immediate-release formulation require patients to awaken 2.5-4 h after their bedtime dose to take a second dose. A novel extended-release, once-nightly sodium oxybate formulation (ON-SXB; FT218) is under US Food and Drug Administration review for the treatment of adults with narcolepsy.

OBJECTIVE

A phase III trial of ON-SXB in individuals with narcolepsy type 1 (NT1) or 2 (NT2) [the REST-ON trial; NCT02720744] has been conducted and the primary results reported elsewhere. Secondary objectives from REST-ON were to assess the efficacy of ON-SXB on disrupted nighttime sleep; the results of this analysis are reported here.

METHODS

In the double-blind, phase III REST-ON trial, patients aged ≥ 16 years were randomly assigned 1:1 to ON-SXB (1 week, 4.5 g; 2 weeks, 6 g; 5 weeks, 7.5 g; 5 weeks, 9 g) or placebo. Secondary endpoints included polysomnographic measures of sleep stage shifts and nocturnal arousals and patient-reported assessments of sleep quality and refreshing nature of sleep at 6, 7.5, and 9 g; post hoc analyses included changes in time spent in each sleep stage, delta power, and assessments in stimulant-use subgroups for prespecified endpoints.

RESULTS

In total, 190 participants (n = 97, ON-SXB; n = 93, placebo) were included in the efficacy analyses. All three ON-SXB doses demonstrated a clinically meaningful, statistically significant decrease vs placebo in the number of transitions to wake/N1 from N1, N2, and rapid eye movement (REM) stages (all doses p < 0.001) and the number of nocturnal arousals (p < 0.05 ON-SXB 6 g; p < 0.001 7.5 and 9 g). Sleep quality and refreshing nature of sleep were significantly improved with all three ON-SXB doses vs placebo (p < 0.001). Post hoc analyses revealed a significant reduction in time spent in N1 (p < 0.05 ON-SXB 6 g; p < 0.001 7.5 and 9 g) and REM (all p < 0.001) and increased time spent in N3 with ON-SXB vs placebo (all p < 0.001), with a significant increase in delta power (p < 0.01 ON-SXB 6 g; p < 0.05 7.5 g; p < 0.001 9 g) and increased REM latency (ON-SXB 7.5 g vs placebo; p < 0.05). Significant improvements in disrupted nighttime sleep were observed regardless of concomitant stimulant use.

CONCLUSIONS

The clinically beneficial, single nighttime dose of ON-SXB significantly improved disrupted nighttime sleep in patients with narcolepsy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02720744.

Recent cannabis use and nightly sleep duration in adults: a population analysis of the NHANES from 2005 to 2018

BACKGROUND

While popularly consumed for its perceived benefits as a sleeping aid, the impact of cannabis on sleep-wake regulation in clinical studies is inconclusive. The purpose of this study was to determine the relationship between cannabis use and nightly sleep duration in a nationally representative dataset.

METHODS

A cross-sectional analysis of adults was undertaken using the National Health and Nutrition Examination Survey data from 2005 to 2018. Respondents were dichotomized as recent users or non-users if they had used or not used cannabis in the past 30 days, respectively. The primary outcome was nightly sleep duration, categorized as short (<6 hours), optimal (6-9 hours), and long (>9 hours). Multinomial logistic regression was used to adjust for sociodemographic and health-related covariates, and survey sample weights were used in modeling.

RESULTS

From a sample representing approximately 146 million adults in the USA, 14.5% reported recent cannabis use. In an adjusted analysis, recent users were more likely than non-users to report both short sleep (OR 1.34, 95% CI 1.12 to 1.59, p<0.001) and long sleep (OR 1.56, 95% CI 1.25 to 1.96, p<0.001). Heavy users (≥20 of the past 30 days) were even more likely to be at the extremes of nightly sleep duration.

DISCUSSION

Recent cannabis use was associated with the extremes of nightly sleep duration in a nationally representative sample of adults, with suggestions of a dose-response relationship. Our findings highlight the need to further characterize the sleep health of regular cannabis users in the population.

Current Management of Residual Excessive Daytime Sleepiness Due to Obstructive Sleep Apnea: Insights for Optimizing Patient Outcomes

Although excessive daytime sleepiness (EDS) attributable to obstructive sleep apnea (OSA) can be resolved by consistent usage of and effective treatment (often with the use of continuous positive airway pressure therapy), 12–58% of patients report residual EDS (REDS). While REDS is difficult to treat, a proportion of cases are possibly due to reversible issues, and wake-promoting medications can prove useful for the remaining cases. Given the challenges associated with effective management of REDS and its relationship to multiple comorbidities, multidisciplinary management of patients with REDS is often recommended. Here we aim to bridge the knowledge gap on the burden, risk factors, prevalence, and potential pathophysiologic mechanisms of REDS in patients with OSA after first-line treatment. The roles of primary care physicians and sleep specialists, as well as the importance of the use of objective assessment tools for the evaluation of REDS and the effective management of comorbidities, are discussed. An update of approved treatments and emerging candidate treatments is also presented.

Histamine H3 and H4 receptors modulate Parkinson's disease induced brain pathology. Neuroprotective effects of nanowired BF-2649 and clobenpropit with anti-histamine-antibody therapy

Military personnel deployed in combat operations are highly prone to develop Parkinson's disease (PD) in later lives. PD largely involves dopaminergic pathways with hallmarks of increased alpha synuclein (ASNC), and phosphorylated tau (p-tau) in the cerebrospinal fluid (CSF) precipitating brain pathology. However, increased histaminergic nerve fibers in substantia nigra pars Compacta (SNpc), striatum (STr) and caudate putamen (CP) associated with upregulation of Histamine H3 receptors and downregulation of H4 receptors in human cases of PD is observed in postmortem cases. These findings indicate that modulation of histamine H3 and H4 receptors and/or histaminergic transmission may induce neuroprotection in PD induced brain pathology. In this review effects of a potent histaminergic H3 receptor inverse agonist BF-2549 or clobenpropit (CLBPT) partial histamine H4 agonist with H3 receptor antagonist, in association with monoclonal anti-histamine antibodies (AHmAb) in PD brain pathology is discussed based on our own observations. Our investigation shows that chronic administration of conventional or TiO₂ nanowired BF 2649 (1mg/kg, i.p.) or CLBPT (1mg/kg, i.p.) once daily for 1 week together with nanowired delivery of HAmAb (25μL) significantly thwarted ASNC and p-tau levels in the SNpC and STr and reduced PD induced brain pathology. These observations are the first to show the involvement of histamine receptors in PD and opens new avenues for the development of novel drug strategies in clinical strategies for PD, not reported earlier.

Pitolisant, a wake-promoting agent devoid of psychostimulant properties: Preclinical comparison with amphetamine, modafinil, and solriamfetol

Several therapeutic options are currently available to treat excessive daytime sleepiness (EDS) in patients suffering from narcolepsy or obstructive sleep apnea. However, there are no comparisons between the various wake-promoting agents in terms of mechanism of action, efficacy, or safety. The goal of this study was to compare amphetamine, modafinil, solriamfetol, and pitolisant at their known primary pharmacological targets, histamine H3 receptors (H3R), dopamine, norepinephrine, and serotonin transporters, and in various in vivo preclinical models in relation to neurochemistry, locomotion, behavioral sensitization, and food intake. Results confirmed that the primary pharmacological effect of amphetamine, modafinil, and solriamfetol was to increase central dopamine neurotransmission, in part by inhibiting its transporter. Furthermore, solriamfetol increased levels of extracellular dopamine in the nucleus accumbens, and decreased the 3,4-dihydroxyphenyl acetic acid (DOPAC)/DA ratio in the striatum, as reported for modafinil and amphetamine. All these compounds produced hyperlocomotion, behavioral sensitization, and hypophagia, which are common features of psychostimulants and of compounds with abuse potential. In contrast, pitolisant, a selective and potent H3R antagonist/inverse agonist that promotes wakefulness, had no effect on striatal dopamine, locomotion, or food intake. In addition, pitolisant, devoid of behavioral sensitization by itself, attenuated the hyperlocomotion induced by either modafinil or solriamfetol. Therefore, pitolisant presents biochemical, neurochemical, and behavioral profiles different from those of amphetamine and other psychostimulants such as modafinil or solriamfetol. In conclusion, pitolisant is a differentiated therapeutic option, when compared with psychostimulants, for the treatment of EDS, as this agent does not show any amphetamine-like properties within in vivo preclinical models.

Drugs for patients with epilepsy and excessive daytime sleepiness

Excessive daytime sleepiness (EDS) and attentional deficits are often observed in people with epilepsy. They may be the consequence of seizures and subclinical discharges as well as of comorbid conditions as obstructive sleep apnea/hypopnea syndrome (OSAS), attention deficit hyperactivity disorder (ADHD), or other less frequent disorders. Excessive daytime sleepiness may also be caused or worsened by antiseizure medications (ASMs). Several meta-analyses suggested that lamotrigine, lacosamide, and perhaps eslicarbazepine are less sedative than other traditional and new ASMs and, in patients prone to somnolence, might be preferred over ASMs with more sedative properties. In patients with severe EDS and/or ADHD, advantages and risks of a treatment with a psychostimulant need to be considered. Methylphenidate, modafinil, armodafinil, pitolisant, and solriamfetol are authorized for use in ADHD and EDS in patients with narcolepsy and some of them also in OSAS. These agents are off-label for the treatment of EDS associated with epilepsy. They do not have proconvulsant effects, although there are several possible risks for patients with epilepsy. The risks of cardiovascular events and psychiatric symptoms should be carefully evaluated as such disorders can coexist with epilepsy and be triggered by these agents. Finally, combination of psychostimulants with ASMs may be associated with several pharmacokinetic drug-drug interactions.

Efficacy of Pitolisant on the Treatment of Narcolepsy: A Systematic Review

Narcolepsy is characterized by excessive daytime sleepiness (EDS) and cataplexy. Histamine neurons play an important role in enhancing wakefulness. The objective of our study was to evaluate the efficacy of pitolisant, a histamine 3 (H3)-receptor antagonist/inverse agonist, in patients with a high burden of narcolepsy symptoms. We conducted an advanced PubMed search strategy with inclusion and exclusion criteria. The outcome included the Epworth Sleepiness Scale (ESS) and adverse effects frequency. Our primary outcome included the mean ESS score at the endpoint and showed that pitolisant was superior to the placebo, but not non-inferior to modafinil. Adverse effects were less common and shorter in duration in the pitolisant group compared to the modafinil-treated patients. Pitolisant was efficacious in reducing excessive daytime sleepiness and cataplexy compared with placebo, and it was well-tolerated in patients with severe narcolepsy symptoms as compared with modafinil.

Pharmacokinetics, bioavailability, and bioequivalence of lower-sodium oxybate in healthy participants in two open-label, randomized, crossover studies

American Academy of Sleep Medicine practice parameters designate sodium oxybate (SXB) as a standard of care for cataplexy, excessive daytime sleepiness (EDS), and disrupted night‐time sleep in narcolepsy. Recently, a lower‐sodium oxybate (LXB) with 92% less sodium than SXB was approved in the United States for the treatment of cataplexy or EDS in patients 7 years of age and older with narcolepsy. Two phase I, open‐label, randomized, single‐dose crossover pharmacokinetic studies in healthy adults were conducted. Single 4.5‐g oral doses of LXB and SXB were administered in a fasted or fed state. In the fasted state at equivalent oxybate doses, LXB, compared with SXB, had a lower maximum plasma concentration (C_max; study 1 [total aqueous volume, 240 ml]: 101.8 vs. 135.7 µg/ml; study 2 [60 ml]: 94.6 vs. 123.0 μg/ml), delayed time to C_max (T_max; study 1: 0.75 vs. 0.5 h; study 2: 1.0 vs. 0.5 h), but similar area under the curve (AUC; study 1: AUC_0‐t, 235.4 vs. 263.9 μg∙h/ml; AUC_0‐∞, 236.5 vs. 265.2 μg∙h/ml; study 2: AUC_0‐t, 241.5 vs. 254.7 μg∙h/ml; AUC_0‐∞, 243.1 vs. 256.3 μg∙h/ml). Bioequivalence criteria were met for AUC but not C_max (both studies). C_max and AUC were lower under fed than fasted conditions (LXB and SXB); differences between fed versus fasted were smaller for LXB than SXB. These pharmacokinetic differences between LXB and SXB are likely due to the lower sodium content in LXB. Pooled analyses demonstrated that a higher C_max is associated with a higher incidence of nausea and vomiting.

Narcolepsy: A clinical review

ABSTRACT

Narcolepsy continues to be a significantly underdiagnosed/misdiagnosed condition worldwide. According to the National Institutes of Health (NIH), an estimated 135,000 to 200,000 patients in the United States are living with narcolepsy. However, due to the number of patients who either do not seek medical advice for their symptoms or receive an incorrect initial diagnosis at onset, this number may be higher. This article reviews the different subtypes of narcolepsy along with the pathophysiology, screening guidelines, clinical features, diagnosis, and management of the disorder. Educational awareness from a healthcare and patient standpoint can enhance early detection and accurate diagnosis of narcolepsy and improve patient quality of life.

A Randomized, Double-Blind, Placebo- and Positive-Controlled, 4-Period Crossover Study of the Effects of Solriamfetol on QTcF Intervals in Healthy Participants

Solriamfetol, a dopamine and norepinephrine reuptake inhibitor, is approved (United States and European Union; Sunosi) to treat excessive daytime sleepiness associated with narcolepsy (75-150 mg/day) or obstructive sleep apnea (37.5-150 mg/day). A thorough QT/QTc study assessed solriamfetol effects on QT interval (Fridericia correction for heart rate; QTcF). This randomized, double-blind, placebo- and positive-controlled, 4-period crossover study compared single doses of 300 and 900 mg solriamfetol, 400 mg moxifloxacin, and placebo in healthy adults. Placebo- and predose-adjusted mean differences in QTcF (ddQTcF; primary end point) were analyzed, and solriamfetol pharmacokinetics were characterized. Fifty-five participants completed all periods. Upper bounds of 2-sided 90% confidence intervals (CIs) for ddQTcF for both solriamfetol doses were <10 milliseconds at all postdose time points. Assay sensitivity was demonstrated with moxifloxacin; lower bounds of 2-sided 90%CIs for ddQTcF > 5 milliseconds at 1, 2, and 3 hours postdose. There were no QTcF increases > 60 milliseconds or QTcF values > 480 milliseconds at either solriamfetol dose. Solriamfetol median tmax was 2-3 hours; exposure was dose-proportional. More participants experienced adverse events (AEs) after solriamfetol 900 versus 300 mg (70% vs 29%); none were serious (all mild/moderate), and there were no deaths. Common AEs were nausea, dizziness, and palpitations. Neither solriamfetol dose resulted in QTcF prolongation > 10 milliseconds.

Pharmacokinetics of FT218, a Once-Nightly Sodium Oxybate Formulation in Healthy Adults

PURPOSE

FT218 is an investigational, once-nightly, modified-release formulation of sodium oxybate (SO). SO effectively treats excessive daytime sleepiness and cataplexy in patients with narcolepsy. Current approved SO formulations, at effective doses of 6, 7.5, and 9 g, require twice-nightly divided dosing, with the first dose taken at bedtime and the second 2.5-4 h later. The purpose of the following studies was to evaluate the pharmacokinetic properties, safety profile, and tolerability of FT218 in healthy adults.

METHODS

Four crossover, single-dose studies were conducted. The first was a pilot study (n = 16) that compared 3 prototype formulations of FT218 4.5 g to twice-nightly SO 4.5 g (2 divided doses of 2.25 g); the second, a dose-proportionality study (n = 20) that evaluated FT218 4.5, 7.5, and 9 g; the third, a relative bioavailability study (n = 28) that compared FT218 6 g with twice-nightly SO 6 g (2 divided doses of 3 g); and the fourth, a food-effect study (n = 16) of FT218 6 g.

RESULTS

In the pilot study, FT218 prototype 2 had a lower C_max, lower plasma concentration 8 h after dosing (C_8h), similar exposure (AUC), and comparable interperson variability to twice-nightly SO 4.5 g. Exploratory pharmacodynamic data indicated similar sleep quality and morning alertness between FT218 and twice-nightly SO. Prototype 2 was selected for further development. In the dose-proportionality study, FT218 had dose proportionality for C_max and slightly more than dose proportionality for AUC. The relative bioavailability study confirmed that FT218 6 g had lower C_max and C_8h than twice-nightly SO 6 g but equivalent AUC and comparable variability. In the food-effect study, FT218 6 g had longer t_max (1 h later), lower C_max (67%), and decreased AUC (86%) in fed versus fasted states. For all studies, adverse events with FT218 were mostly mild or moderate in severity, nonserious, and known to be associated with SO. Most common adverse events included somnolence, dizziness, and nausea. Safety profiles of FT218 and twice-nightly SO at 4.5 and 6 g were similar.

IMPLICATIONS

Once-nightly FT218 at 4.5 and 6 g had lower overall C_max and C_8h and similar exposure and variability compared with twice-nightly SO. FT218 was generally well tolerated and comparable to twice-nightly SO.

Structures of active-state orexin receptor 2 rationalize peptide and small-molecule agonist recognition and receptor activation

Narcolepsy type 1 (NT1) is a chronic neurological disorder that impairs the brain’s ability to control sleep-wake cycles. Current therapies are limited to the management of symptoms with modest effectiveness and substantial adverse effects. Agonists of the orexin receptor 2 (OX₂R) have shown promise as novel therapeutics that directly target the pathophysiology of the disease. However, identification of drug-like OX₂R agonists has proven difficult. Here we report cryo-electron microscopy structures of active-state OX₂R bound to an endogenous peptide agonist and a small-molecule agonist. The extended carboxy-terminal segment of the peptide reaches into the core of OX₂R to stabilize an active conformation, while the small-molecule agonist binds deep inside the orthosteric pocket, making similar key interactions. Comparison with antagonist-bound OX₂R suggests a molecular mechanism that rationalizes both receptor activation and inhibition. Our results enable structure-based discovery of therapeutic orexin agonists for the treatment of NT1 and other hypersomnia disorders.

Agonists of the orexin receptor 2 (OX₂R) show promise in the treatment of narcolepsy. Cryo-EM structures of active-state OX₂R bound to an endogenous peptide agonist and a small-molecule agonist suggest a molecular mechanism that rationalizes both receptor activation and inhibition.

Connexins as therapeutic targets in neurological and neuropsychiatric disorders

Astrocytes represent the reticular part of the central nervous system; gap junctions formed by connexins Cx43, Cx30- and Cx26 provide for homocellular astrocyte-astrocyte coupling, whereas connexins Cx30, Cx32, Cx43, and Cx47 connect astrocytes and oligodendrocytes. Astroglial networks are anatomically and functionally segregated being homologous to neuronal ensembles. Connexons, gap junctions and hemichannels (unpaired connexons) are affected in various neuropathologies from neuropsychiatric to neurodegenerative diseases. Manipulation of astrocytic connexins modulates the size and outreach of astroglial syncytia thus affecting astroglial homeostatic support. Modulation of astrocytic connexin significantly modifies pharmacological profile of many CNS drugs, which represents an innovative therapeutic approach for CNS disorders; this approach is now actively tested in pre-clinical and clinical studies. Wide combination of connexin modulators with CNS drugs open new promising perspectives for fundamental studies and therapeutic strategies.

Pitolisant to Treat Excessive Daytime Sleepiness and Cataplexy in Adults with Narcolepsy: Rationale and Clinical Utility

Narcolepsy is a sleep disorder marked by chronic, debilitating excessive daytime sleepiness and can be associated with cataplexy, sleep paralysis and sleep-related hallucinations. Pharmacological therapy for narcolepsy primarily aims to increase wakefulness and reduce cataplexy attacks. Pitolisant is a first-in-class agent utilizing histamine to improve wakefulness by acting as an antagonist/inverse agonist of the presynaptic histamine 3 receptor. This review summarizes the clinical efficacy, safety and tolerability of pitolisant in treating the symptoms of narcolepsy. Randomized and observational studies demonstrate pitolisant to be effective in treating both hypersomnolence and cataplexy while generally being well tolerated at prescribed doses. The most common adverse reactions include headache, insomnia and nausea.

Schisandrin B exerts hypnotic effects in PCPA-treated rats by increasing hypothalamic 5-HT and γ-aminobutyric acid levels

Schisandrin B (SchB) is one of the primary active components of Schisandra chinensis (Turcz.) Baill., a traditional Chinese herb that has been used to treat insomnia for hundreds of years. Our previous studies revealed that SchB exerts sedative and hypnotic effects, increasing the content of γ-aminobutyric acid (GABA) and the expression of its receptors in the brain tissues of rats. 5-hydroxytryptamine (5-HT) is another important neurotransmitter involved in sleep regulation, although, to the best of our knowledge, there are no reports of its association with SchB. Therefore, the present study aimed to determine whether the hypnotic effect of SchB was partly due to alterations in the expression of 5-HT. The results indicated that SchB reduced sleep latency and increased sleep duration in parachlorophenylalanine (PCPA)-induced rats with insomnia by increasing 5-HT and 5-hydroxyindoleacetic acid, and upregulating the expression of the 5-HT receptor 1A in the hypothalamus. SchB also increased the ratio of GABA to glutamic acid and the activity of glutamic acid decarboxylase, decreased the activity of GABA transaminase, and upregulated the expression of GABA_A receptor α1 and GABA_A receptor γ2 in the rat hypothalamus. These results suggested that SchB improved PCPA-induced insomnia in rats, and its effects may be associated with the regulation of GABA and 5-HT levels in the hypothalamus.

Evaluating pitolisant as a narcolepsy treatment option

INTRODUCTION

Narcolepsy is a chronic sleep disorder characterized by a pentad of excessive daytime sleepiness (EDS), cataplexy, sleep paralysis, hypnagogic/hypnopompic hallucinations, and disturbed nocturnal sleep. Treatment of narcolepsy remains challenging and current therapy is strictly symptomatically based.

AREAS COVERED

The present manuscript is based on an extensive Internet and PubMed search from 1990 to 2020. It is focused on the clinical and pharmacological properties of pitolisant in the treatment of narcolepsy.

EXPERT OPINION

Currently there is no cure for narcolepsy. Although efforts have been made, current treatments do not always allow to obtain an optimal control of symptoms. Pitolisant is an antagonist/inverse agonist of the histamine H3 autoreceptor. Its mechanism of action is novel and distinctive compared to the other available therapies for narcolepsy. Clinical trials suggest that pitolisant administered at a dose of ≤36 mg/day is an effective treatment option for narcolepsy, reducing EDS and cataplexy. Pitolisant is available as oral tablets and offers a convenient once-daily regimen. Pitolisant is generally well tolerated and showed minimal abuse potential in animals and humans. Long-term studies comparing the effectiveness and tolerability of pitolisant with active drugs (e.g. modafinil, sodium oxybate) are needed.