Orexin Receptor Antagonism: Normalizing Sleep Architecture in Old Age and Disease.

Sleep is essential for human well-being, yet the quality and quantity of sleep reduce as age advances. Older persons (>65 years old) are more at risk of disorders accompanied and/or exacerbated by poor sleep. Furthermore, evidence supports a bidirectional relationship between disrupted sleep and Alzheimer's disease (AD) or related dementias. Orexin/hypocretin neuropeptides stabilize wakefulness, and several orexin receptor antagonists (ORAs) are approved for the treatment of insomnia in adults. Dysregulation of the orexin system occurs in aging and AD, positioning ORAs as advantageous for these populations. Indeed, several clinical studies indicate that ORAs are efficacious hypnotics in older persons and dementia patients and, as in adults, are generally well tolerated. ORAs are likely to be more effective when administered early in sleep/wake dysregulation to reestablish good sleep/wake-related behaviors and reduce the accumulation of dementia-associated proteinopathic substrates. Improving sleep in aging and dementia represents a tremendous opportunity to benefit patients, caregivers, and health systems.

Respiratory safety of lemborexant in adult and elderly subjects with moderate-to-severe chronic obstructive pulmonary disease.

Because some hypnotics worsen respiratory conditions, it was important to determine the respiratory safety of lemborexant, a competitive dual orexin-receptor antagonist approved to treat adults with insomnia, in subjects with moderate-to-severe chronic obstructive pulmonary disease. E2006-A001-113 (Study 113; NCT04647383) was a multicentre, multiple-dose, randomised, double-blind, placebo-controlled, two-period crossover study in adult subjects with moderate or severe chronic obstructive pulmonary disease (per spirometry-based Global Initiative for Chronic Obstructive Lung Disease [GOLD] criteria). Subjects (N = 30) were randomised to two treatment sequences comprising 8-night treatment periods (washout ≥ 14 days) with lemborexant 10 mg or placebo. Peripheral oxygen saturation (SpO2; primary endpoint), apnea-hypopnea index, objective sleep parameters and sleep architecture measures were assessed after single (Day 1) and multiple (Day 8) doses. There was no significant difference in least-squares mean SpO2 after a single dose of lemborexant (91.1%) versus placebo (91.5%). Although a statistically significant difference in SpO2 was observed after multiple doses (least-squares mean: lemborexant, 91.3%; placebo, 90.8%) favouring lemborexant, this was not considered clinically meaningful. Apnea-hypopnea index was not significantly different between treatments after single or multiple doses. Total sleep time and total rapid eye movement sleep were significantly greater on Days 1 and 8 with lemborexant versus placebo. Treatment-emergent adverse events were reported in five (16.7%) subjects when taking lemborexant and four (13.3%) subjects when taking placebo; treatment-emergent adverse events were mostly mild. Lemborexant was well tolerated and did not adversely impact SpO2 or apnea-hypopnea index after single and multiple doses relative to placebo in subjects with moderate-to-severe chronic obstructive pulmonary disease.

Lemborexant levels in breast milk after single doses in healthy, lactating women.

AIMS: The aim of this study is to determine the cumulative amount of lemborexant (a competitive dual orexin receptor antagonist approved to treat adults with insomnia) excreted in human breast milk and the relative infant dose (RID) as a proportion of daily maternal dose. METHODS: E2006-A001-010 was a single-centre, open-label study that enrolled lactating women (≥18 years) who breastfed for ≥5 weeks postpartum. After overnight fasting, subjects received a single 10-mg oral dose of lemborexant. Using a standardized electric pump, milk was sampled before and ≤240 h (10 days) after dosing; combined and total volume were recorded. The cumulative total amount of lemborexant excreted, fraction of dose excreted, daily infant dose and RID were calculated. Lemborexant concentration in human milk was assessed by liquid chromatography with tandem mass spectrometry. RESULTS: Eight subjects completed the study. The mean cumulative total amount of lemborexant reached 0.0174 mg (coefficient of variation [CV] 54.5%; 0.174% of lemborexant 10 mg administered) in breast milk at 240 h (10 days); ~70% of excreted lemborexant accumulated in the first 24 h. For an infant weighing 6 kg, the daily infant dose was 0.00290 mg kg-1 (CV 54.5%) and the RID was 1.96% (CV 63.1%) of daily maternal dose. Mild treatment-emergent adverse events were reported in 4 subjects; these all resolved by end of study. CONCLUSION: Trace quantities of lemborexant were found in human breast milk. Lemborexant was well tolerated by healthy lactating women.

Effect of lemborexant on pharmacokinetics of clozapine: A potential drug-drug interaction mediated by time-dependent inhibition of CYP3A4.

Clozapine (CLZ) is extensively used for treatment-resistant schizophrenia (TRS) with caution to avoid serious adverse events such as agranulocytosis and drug-drug interactions (DDIs). In the current report, we present a case of a 35-year-old male non-smoking TRS patient whose steady-state plasma trough concentrations (Ctrough ) of CLZ and its active metabolite, N-desmethylclozapine (NDMC), were significantly increased after initiating oral administration of lemborexant (LEM), a dual orexin receptor antagonist, for the treatment of insomnia. The patient experienced oversedation with sleepiness and fatigue while maintaining high levels of Ctrough of CLZ. The increased concentrations of CLZ returned to normal ranges after the discontinuation of LEM dosing, implying a pharmacokinetic DDI between CLZ and LEM. To gain insight into possible mechanisms, we performed in vitro assays of CYP1A2- and CYP3A4-mediated CLZ metabolism by measuring the formations of NDMC and clozapine N-oxide (CNO). In accordance with previous studies, the incubation of CLZ with each enzyme resulted in the production of both metabolites. LEM had only a weak inhibitory effect on CYP1A2- and CYP3A4-mediated CLZ metabolism. However, the preincubation of LEM with CYP3A4 in the presence of NADPH showed a significant enhancement of inhibitory effects on CLZ metabolism with IC50 values for the formations of CNO and NDMC of 2.8 µM and 4.1 µM, respectively, suggesting that LEM exerts as a potent time-dependent inhibitor for CYP3A4. Taken together, the results of the current study indicate that co-medication of CLZ with LEM may lead to increase in exposure to CLZ and risks of CLZ-related adverse events.

Improvement of sleep and pain with lemborexant administration in patients with chronic pain: a retrospective observational study.

OBJECTIVE: Patients with chronic pain often have sleep disturbances, and many patients receive sleep medications in addition to analgesics. Although there have been scattered reports of negative pain-sleep interactions, only a few reports have investigated the efficacy of sleep medication interventions in patients with chronic pain for improving sleep disturbances and reducing pain. We retrospectively examined whether lemborexant, an orexin receptor antagonist, is effective in improving sleep disturbances and reducing pain in patients with chronic pain. This study was approved by the Ethics Committee of our hospital. METHODS: The subjects were 26 patients with chronic pain undergoing treatment at our pain clinic between July 2021 and March 2022, who had been diagnosed with insomnia, with an Athens Insomnia Scale (AIS) score of ≥6 and had been started on lemborexant. The AIS score and pain score (Numeric Rating Scale [NRS]) before and after 2 and 4 weeks of starting lemborexant were investigated. RESULTS: Patients who were already taking other sleep medications, such as benzodiazepines were switched to 5 mg of lemborexant after all the other sleep medications were discontinued. Those who had not yet used sleeping pills were started on 5 mg of lemborexant. During the study course, the dose of lemborexant was adjusted at the discretion of the attending physician, based on improvement of insomnia symptoms and secondary symptoms, such as daytime sleepiness and lightheadedness. The study finally included 21 patients, excluding 5 who could not continue taking lemborexant due to side effects, such as lightheadedness. The AIS scores significantly improved, decreasing from baseline (mean ± standard deviation: 12.5 ± 4.9) to 2 weeks (7.8 ± 3.1) and 4 weeks (5.3 ± 2.9) after the start of lemborexant. No significant difference was observed in the degree of improvement in sleep disturbance between patients with or without previous sleep medications, and there was also no statistically significant improvement in the NRS score before (6.1 ± 2.7) and after 2 weeks (5.5 ± 2.3) and 4 weeks (5.9 ± 2.2) from treatment initiation.

The orexin story and orexin receptor antagonists for the treatment of insomnia.

Insomnia is present in up to one third of the adult population worldwide, and it can present independently or with other medical conditions such as mental, metabolic, or cardiovascular diseases, which highlights the importance of treating this multifaceted disorder. Insomnia is associated with an abnormal state of hyperarousal (increased somatic, cognitive, and cortical activation) and orexin has been identified as a key promotor of arousal and vigilance. The current standards of care for the treatment of insomnia recommend non-pharmacological interventions (cognitive behavioural therapy) as first-line treatment and, if behavioural interventions are not effective or available, pharmacotherapy. In contrast to most sleep medications used for decades (benzodiazepines and 'Z-drugs'), the new orexin receptor antagonists do not modulate the activity of γ-aminobutyric acid receptors, the main inhibitory mechanism of the central nervous system. Instead, they temporarily block the orexin pathway, causing a different pattern of effects, e.g., less morning or next-day effects, motor dyscoordination, and cognitive impairment. The pharmacokinetic/pharmacodynamic properties of these drugs are the basis of the different characteristics explained in the package inserts, including the recommended starting dose. Orexin receptor antagonists seem to be devoid of any dependence and tolerance-inducing effects, rendering them a viable option for longer-term treatment. Safety studies did not show exacerbation of existing respiratory problems, but more real-world safety and pharmacovigilance experience is needed. This review provides an overview of the orexin history, the mechanism of action, the relation to insomnia, and key features of available drugs mediating orexin signalling.

Efficacy and safety of lemborexant as an alternative drug for patients with insomnia taking gamma-aminobutyric acid-benzodiazepine receptor agonists or suvorexant.

BACKGROUND: Although gamma-aminobutyric acid-benzodiazepine (GABA-BZ) receptor agonists are used to treat insomnia, their long-term or high-dosage use causes adverse events. Nevertheless, evidence regarding the discontinuation and replacement of GABA-BZ receptor agonists with alternative agents is lacking. Suvorexant (SUX), an existing orexin receptor antagonist, is effective in preventing nocturnal awakening in 70%-75% of patients with insomnia. METHODS: The novel dual orexin receptor antagonist lemborexant (LEM) has fewer adverse effects than GABA-BZ receptor agonists. Therefore, in this retrospective study, we categorised patients taking GABA-BZ receptor agonists and SUX into LEM-treated (switched) and non-treated (non-switched) groups and compared their outcomes over a 12-week period. RESULTS: The GABA-BZ group (N = 59) comprised 34 'switched' and 25 'non-switched' and the SUX group (N = 14) comprised 6 'switched' and 8 'non-switched' patients. A mixed model showed a significant diazepam equivalence reduction in patients taking GABA-BZ receptor agonists and improved Athens Insomnia Scale score in those taking SUX. The safety and tolerability of GABA-BZ receptor agonists and SUX were high, and no serious adverse effects were observed after switching to LEM. CONCLUSIONS: Lemborexant may be a useful alternative for long-term GABA-BZ receptor agonist users. For SUX, the number of cases (N = 6) was insufficient to draw definite conclusions.

Comparative efficacy and safety of lemborexant 5 mg versus 10 mg for the treatment of insomnia: a systematic review.

INTRODUCTION: Insomnia is a common condition that may be caused by or coexist with other medical or psychological illnesses. Nearly a quarter of a billion people across the globe suffer from insomnia frequently. Lemborexant, a dual orexin receptor antagonist, is a recently authorized hypnotic-based medication for insomnia. The purpose of this systematic review is to further investigate its efficacy and safety profile, with the primary goal of comparing the effects of two FDA-approved doses of lemborexant, 5 mg and 10 mg (LEM5 and LEM10, respectively). MATERIALS AND METHODS: PubMed, Google Scholar, ClinicalTrials.gov, and Cochrane Central were searched for relevant literature, and studies were considered if they compared the efficacy and safety of lemborexant 5 mg to lemborexant 10 mg. This study comprised clinical trials. RESULTS: A total of 6 studies were evaluated for efficacy and safety of lemborexant therapy. They reported a significant betterment in values pertaining to sleep efficacy, sleep onset latency, wake after sleep onset, total sleep time, sleep quality, ISI score, and morning alertness. The results presented a dose-dependent pattern and showed slight variation with the different dosages. The most prevalent side effects noted were somnolence, headaches, and dizziness, with infections like UTIs and upper respiratory tract infections also being commonly reported. The incidence is rather ambiguous and not sincerely dose-dependent. The differences between results for LEM5 and LEM10 do not exhibit a wide variation, although slight dose-dependent alterations are noted. CONCLUSION: Lemborexant is well integrated with the amelioration of sleep disturbances in insomniac patients, as shown by a decrease in eSOL and sWASO and a rise in sSE, sTST, quality of sleep, and morning alertness. Effects last 12 months after therapy.

Hypocretins (orexins): The ultimate translational neuropeptides.

The hypocretins (Hcrts), also known as orexins, are two neuropeptides produced exclusively in the lateral hypothalamus. They act on two specific receptors that are widely distributed across the brain and involved in a myriad of neurophysiological functions that include sleep, arousal, feeding, reward, fear, anxiety and cognition. Hcrt cell loss in humans leads to narcolepsy with cataplexy (narcolepsy type 1), a disorder characterized by intrusions of sleep into wakefulness, demonstrating that the Hcrt system is nonredundant and essential for sleep/wake stability. The causal link between Hcrts and arousal/wakefulness stabilisation has led to the development of a new class of drugs, Hcrt receptor antagonists to treat insomnia, based on the assumption that blocking orexin-induced arousal will facilitate sleep. This has been clinically validated: currently, two Hcrt receptor antagonists are approved to treat insomnia (suvorexant and lemborexant), with a New Drug Application recently submitted to the US Food and Drug Administration for a third drug (daridorexant). Other therapeutic applications under investigation include reduction of cravings in substance-use disorders and prevention of neurodegenerative disorders such as Alzheimer's disease, given the apparent bidirectional relationship between poor sleep and worsening of the disease. Circuit neuroscience findings suggest that the Hcrt system is a hub that integrates diverse inputs modulating arousal (e.g., circadian rhythms, metabolic status, positive and negative emotions) and conveys this information to multiple output regions. This neuronal architecture explains the wealth of physiological functions associated with Hcrts and highlights the potential of the Hcrt system as a therapeutic target for a number of disorders. We discuss present and future possible applications of drugs targeting the Hcrt system for the treatment of circuit-related neuropsychiatric and neurodegenerative conditions.

Cost-effectiveness analysis of lemborexant for treating insomnia in Japan: a model-based projection, incorporating the risk of falls, motor vehicle collisions, and workplace accidents.

BACKGROUND: Lemborexant has demonstrated statistically significant improvements in sleep onset and sleep maintenance compared with placebo and zolpidem tartrate extended release, measured both objectively using polysomnography and subjectively using sleep diaries, in the phase 3 clinical trial SUNRISE 1. This study evaluated the cost-effectiveness of lemborexant compared with suvorexant, zolpidem immediate release (IR), and untreated insomnia. METHODS: A decision-tree model was developed for falls, motor vehicle collisions, and workplace accidents associated with insomnia and insomnia treatments from a Japanese healthcare perspective and with a 6-month time horizon. The model extracted subjective sleep onset latency treatment responses and disutility values for non-responders from SUNRISE 1. Cost-effectiveness was assessed using incremental cost per quality-adjusted life year (QALY) gained. One-way and probabilistic sensitivity analyses were conducted to evaluate the impact of parameter uncertainty on the results. RESULTS: In the base-case analysis, the mean estimated QALYs for lemborexant, suvorexant, zolpidem-IR, and untreated insomnia were 0.4220, 0.4204, 0.4113, and 0.4163, and expected medical costs were JPY 34 034, JPY 38 371, JPY 38 139, and JPY 15 383, respectively. Lemborexant saved JPY 4337 and JPY 4105 compared with suvorexant or zolpidem-IR, respectively, while conferring QALY benefits. The incremental cost-effectiveness ratio (ICER) of lemborexant compared with that of untreated insomnia was JPY 3 220 975 /QALY. Lemborexant was dominant over suvorexant and zolpidem-IR and was cost-effective when compared with untreated insomnia. Sensitivity analyses supported the results' robustness. CONCLUSIONS: In a Japanese clinical practice setting, lemborexant may represent a better investment for treating insomnia in the healthcare system in Japan.

Orexin Receptor Antagonists and Insomnia.

PURPOSE OF REVIEW: We review recent evidence on the use of orexin receptor antagonists (ORAs) for treating insomnia. We evaluate studies on five dual ORAs and one selective ORA. RECENT FINDINGS: Research on suvorexant in recent years gradually focus on comorbid insomnia, while lemborexant and daridorexant were still being validated in primary insomnia. Almorexant is now mainly used as a commercial specific inhibitor of the orexin system in animal studies due to safety issues. Although filorexant has also shown a certain sleep-promoting effect, there are few clinical or experimental studies on sleep-related aspects of filorexant in recent years. As for selective ORAs, orexin receptor 2 antagonist seltorexant still has not yet reached phase 3. High-quality clinical trials in insomnia populations are needed which directly compare authorized ORAs and investigate non-approved ORAs, the use of ORAs in comorbid insomnia, and the orexin signaling system pathophysiology in insomnia.

Lemborexant, an orexin receptor antagonist sedative-hypnotic: Is it useful for insomnia in psychiatric disorders?

OBJECTIVE: Lemborexant, an orexin receptor antagonist similar to suvorexant, has been approved for the treatment of sleep onset and/or maintenance insomnia. Lemborexant is reviewed and compare to suvorexant from a psychiatric perspective. CONCLUSION: Rapidly absorbed (peak 1-3 h), lemborexant has a half-life of 17-19 h (suvorexant half-life 12 h). It is metabolized by CYP3A4/5, with no significant effects of age, sex or weight. Trials for insomnia indicate sustained efficacy beyond 6 months. Lemborexant has not been trialled in major psychiatric disorders. Commenced at 5 mg, lemborexant can then be increased to 10 mg, taken at least 7 h before planned awakening. Adverse effects are higher at 10 mg: somnolence occurs in about 10% while headache and nightmares affect 2-5%, approximately similar to 40 mg suvorexant (recommended suvorexant dose 20 mg). Sleep paralysis, hypnagogic/hypnopompic hallucinations, and cataplexy-like symptoms, complex sleep behaviours and emergence of depression/suicidal ideation can occur. Neither tolerance to sedation nor withdrawal effects on discontinuation have been observed. Whether the differences between lemborexant and suvorexant are clinically relevant is unclear. Like suvorexant, lemborexant appears to be effective in longer-term use for insomnia, but until efficacy and safety are adequately investigated in major mental disorders, clinicians need to monitor patient experience closely.

Effectiveness of change from suvorexant to lemborexant drug in the treatment of sleep disorders.

BACKGROUND: This study aimed to examine the effects of a change in medication from suvorexant to lemborexant among patients with insomnia. METHODS: Patients with chronic insomnia who had persistent insomnia for 3 months or longer and who had been taking suvorexant for 3 months or longer were selected. The participants were divided into two groups: the 'modified' group and the 'non-modified' group. Four sub-types of insomnia (i.e., difficulty initiating sleep, difficulty maintaining sleep, early-morning awakening, and non-restorative sleep) were investigated. Logistic regression was used to investigate improvements in both the groups after 12 weeks. RESULTS: Among the 77 participants, 43 and 34 patients were in the modified drug group and the non-modified drug group, respectively. Comparing sleep disorders between the two groups, we found significant improvement after 12 weeks in the modified drug group in terms of difficulty initiating sleep, compared with the non-modified drug group (odds ratio = 0.036, P = 0.008, 95% CI = 0.003-0.415). However, no significant differences were found between the two groups in terms of difficulty maintaining sleep, early-morning awakening, and non-restorative sleep. CONCLUSIONS: Sleep disorders can be treated by alleviating difficulties in initiating sleep by changing from suvorexant to lemborexant. In addition, it was confirmed that the drug change caused no serious side effects and that it was highly safe and tolerated.

Nonclinical evaluation of abuse liability of the dual orexin receptor antagonist lemborexant.

Lemborexant is a dual orexin receptor antagonist (DORA) approved in multiple countries including the United States, Japan, Canada and Australia for the treatment of adults with insomnia. As required for marketing approval of new compounds with central nervous system activity with sedating effects, the abuse potential of lemborexant was assessed in accordance with regulatory guidelines, which included three nonclinical studies. These assessments comprised physical dependence and drug discrimination studies in rats and a self-administration study in rhesus monkeys. There was no evidence of withdrawal signs following abrupt drug discontinuation, indicating that lemborexant does not induce physical dependence. In the drug discrimination study, lemborexant at doses up to 1000 mg/kg administered orally did not cross-generalize to the zolpidem training stimulus, although another DORA included in the same experiment, suvorexant, showed partial generalization with zolpidem. In rhesus monkeys, lemborexant treatment did not induce any gross behavioral changes, and there was no increase in self-administration rates compared with control, indicative of a lack of reinforcing effects of lemborexant. Collectively, these nonclinical studies support the position that lemborexant, which has been placed in Schedule IV by the United States Drug Enforcement Administration, has a low risk of abuse in humans.

Disposition and metabolism of [14C]lemborexant, a novel dual orexin receptor antagonist, in rats and monkeys.

The disposition and metabolism of lemborexant, a novel dual orexin receptor antagonist currently under development as a therapeutic agent for insomnia disorder, were evaluated after a single oral administration of [14C]lemborexant in Sprague-Dawley rats (10 mg/kg) and cynomolgus monkeys (3 mg/kg). In both species, [14C]lemborexant was rapidly absorbed: radioactivity concentration in blood peaked at 0.83-1.8 h, and decreased with elimination half-life of 110 h. The radioactivity administered was excreted primarily into faeces, with relatively little excreted into urine. Lemborexant was not detected in bile, urine or faeces, indicating that lemborexant administered orally was completely absorbed from the gastrointestinal tract and that the main elimination pathway was metabolism in both species. In rats, lemborexant was found to be minor in plasma (≤5.2% of total radioactivity), and M9 (hydroxylated form) was the major circulating metabolite. In monkeys, the major circulating components were lemborexant, M4 (N-oxide metabolite), M13 (di-oxidised form), M14 (di-oxidised form) and M16 (glucuronide of mono-oxidised form). In both species, lemborexant was metabolised to various metabolites by multiple pathways, the primary of which was oxidation of the dimethylpyrimidine or fluorophenyl moiety.

Impact of zolpidem and lemborexant on sleep and morning symptoms when used as a single dose for polysomnography.

This study evaluated the effect of zolpidem and lemborexant on sleep and morning symptoms in patients undergoing type-1 polysomnography for suspected sleep-disordered breathing based on questionnaires and polysomnography results. We enrolled 127 patients (lemborexant: N = 57, zolpidem: N = 25, without hypnotics: N = 45). Rapid eye movement sleep in patients on lemborexant was higher than that in patients without hypnotics (P = 0.02). Frequency of unsteadiness in the morning was higher in patients on zolpidem than that in patients without hypnotics (P = 0.04), which remained after adjustment for potential confounders (P = 0.03). Low-dose lemborexant might be suitable when administered as a single dose during polysomnography.

Association between the use of orexin receptor antagonists and falls or fractures: A meta-analysis.

Evidence indicates that the use of sedative-hypnotics, including benzodiazepines and z-drugs, is linked to an increased risk of falls and fractures. Nonetheless, the potential exacerbation of this risk by orexin receptor antagonists, which are novel therapeutic agents for treating insomnia, remains uncertain despite their escalating prevalence in clinical practice. We systematically searched four electronic databases from inception to April 17, 2024. In addition, we performed a quality assessment; calculated pooled odds ratios (ORs) to assess the relationship between the use of orexin receptor antagonists and the occurrence of falls or fractures; evaluated heterogeneity across the included studies; and conducted sensitivity analyses. The meta-analysis encompassed eight papers, comprising a total of 46,636 subjects. These papers included 5 case-control studies and 3 randomized controlled trials (RCTs), collectively encompassing ten studies. Analysis of the included case-control studies (pooled adjusted OR = 0.75, 95% confidence interval [CI] = 0.00-1.50, I2 = 66.2%, k = 3) and RCTs (OR = 0.68, 95% CI = 0.31-1.50, I2 = 45.9%, k = 5) indicated that the use of orexin receptor antagonists did not elevate the risk of falls. Similarly, analysis of the included case-control studies revealed no significant increase in the risk of fractures associated with the use of orexin receptor antagonists (pooled adjusted OR = 1.01, 95% CI = 0.82-1.20, I2 = 40.1%, k = 2). This meta-analysis suggests that the use of orexin receptor antagonists for treating insomnia does not escalate the risk of falls or fractures, although the data for lemborexant and daridorexant are limited.

The effect of lemborexant on insomnia in patients with psychiatric disorders: Detailed evaluation using the Athens Insomnia Scale.

Aim: Chronic insomnia disorder is common and associated with reduced quality of life. Benzodiazepine hypnotics are commonly prescribed for insomnia, but have potential side effects such as concentration impairment, somnolence, and dependence. Lemborexant (LEM) is an orexin receptor antagonist considered to have fewer side effects than benzodiazepine hypnotics. This study evaluated the effect of LEM on sleep in detail and examined whether benzodiazepine hypnotics can be gradually tapered by adding LEM. Methods: We retrospectively examined the effectiveness of LEM in 28 outpatients with insomnia. Insomnia symptoms were assessed using the Athens Insomnia Scale (AIS) before and after LEM administration. We also attempted to taper benzodiazepine hypnotics and assessed benzodiazepine dose using diazepam equivalents for some patients taking benzodiazepine hypnotics. Wilcoxon's signed-rank test was used for statistical analysis. Results: The mean AIS score was significantly improved after LEM treatment (8.7 ± 5.2 vs. 3.8 ± 3.3; P < 0.01). Among the AIS subitems, significant improvement was observed for six items: sleep induction, awakenings during the night, sleep quality, well-being, functioning capacity, and sleepiness during the day. The mean benzodiazepine dose was significantly lower after LEM treatment (4.6 ± 5.0 mg vs. 2.1 ± 3.3 mg; P < 0.01). Conclusions: This study indicated the potential of LEM for improving insomnia and reducing benzodiazepine dose.

Transitioning insomnia patients from zolpidem to lemborexant: A multicenter, open-label study evaluating a next-dose transition approach to insomnia pharmacotherapy.

Objective: Few clinical studies have assessed real-world abrupt transitioning between insomnia medications. This study assessed strategies for directly transitioning patients from zolpidem tartrate (ZOL) immediate/extended release to the dual orexin receptor antagonist, lemborexant (LEM). Methods: This randomized, open-label, multicenter study (Study 312; E2006-A001-312) enrolled 53 adults age ≥18 years with insomnia disorder and ≥1-month history of intermittent (3-4 nights/week) or frequent (≥5 nights/week) ZOL use. Subjects recorded their ZOL use in a 3-week Pretreatment Phase, followed by a 2-week Treatment Phase (TRT; Titration) during which ZOL was discontinued. Intermittent ZOL users transitioned to LEM 5 mg (LEM5), Cohort 1, and frequent ZOL users were randomized 1:1 to LEM5, Cohort 2A, or LEM 10 mg (LEM10), Cohort 2B. One dose adjustment was permitted during the TRT. Subjects completing the TRT could continue LEM in the 12-week Extension Phase (EXT). The primary outcome was proportion of subjects who successfully transitioned and remained on LEM at the end of the TRT. Results: Most subjects (43 [81.1 %]) successfully transitioned to LEM (9 [90 %], 17 [81.0 %], and 17 [77.3 %] in Cohorts 1, 2A, and 2B, respectively). By the end of the EXT, 66.7 % in Cohort 1 and 60.0 % in Cohort 2A up-titrated to LEM10, whereas 41.2 % in Cohort 2B down-titrated to LEM5; 61.0 % were receiving LEM10 at study end. At the end of the TRT, more subjects taking LEM reported that it helped them return to sleep after waking, compared with those taking ZOL (71.7 % vs. 49.1 %). There were no important differences between treatments regarding how subjects reported feeling as they fell asleep. Most of the treatment-emergent adverse events with LEM were mild in severity. Conclusions: Most subjects transitioned successfully to LEM from ZOL (intermittent or frequent use). LEM was well tolerated.

Efficacy and Safety of Transitioning to Lemborexant from Z-drug, Suvorexant, and Ramelteon in Japanese Insomnia Patients: An Open-label, Multicenter Study.

INTRODUCTION: For patients with chronic insomnia, conventional therapy may not always provide satisfactory efficacy and safety. Thus, switching to an alternative therapeutic agent can be explored. However, there is a lack of prospective studies evaluating the effectiveness of such changes. This prospective, non-randomized, open-label, interventional, multicenter study assessed whether Japanese patients with chronic insomnia dissatisfied with treatment could transition directly to lemborexant (LEM) from four cohorts-non-benzodiazepine sedative-hypnotic (zolpidem, zopiclone, or eszopiclone) monotherapy, dual orexin receptor antagonist (suvorexant) monotherapy, suvorexant + benzodiazepine receptor agonists (BZRAs), and melatonin receptor agonist (ramelteon) combination. We evaluated whether transitioning to LEM improved patient satisfaction based on efficacy and safety. METHODS: The primary endpoint was the proportion of successful transitions to LEM at 2 weeks (titration phase end), defined as the proportion of patients on LEM by the end of the 2-week titration phase who were willing to continue on LEM during the maintenance phase (Weeks 2-14). Patient satisfaction and safety (the incidence of treatment-emergent adverse events [TEAEs]) were assessed at 14 weeks (end of titration and maintenance phases). RESULTS: Among the 90 patients enrolled, 95.6% (95% confidence interval: 89.0-98.8%) successfully transitioned to LEM at 2 weeks. The proportions of patients who successfully continued on LEM were 97.8% and 82.2% at the end of the titration and maintenance phases (Weeks 2 and 14), respectively. The overall incidence of TEAEs was 47.8%; no serious TEAEs occurred. In all cohorts, the proportions of patients with positive responses were higher than the proportions with negative responses on the three scales of the Patient Global Impression-Insomnia version. During the maintenance phase, Insomnia Severity Index scores generally improved at Weeks 2, 6, and 14 of LEM transition. CONCLUSIONS: Direct transition to LEM may be a valid treatment option for patients with insomnia who are dissatisfied with current treatment. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT04742699.