Transfer of the Dual Orexin Receptor Antagonist Daridorexant into Breast Milk of Healthy Lactating Women

The novel dual orexin receptor antagonist daridorexant was approved in 2022 for the treatment of adult patients with insomnia. The aim of this post-marketing study was to measure daridorexant and its major metabolites in breast milk and plasma of 10 healthy lactating subjects. This single-center, open-label study evaluated the transfer of the analytes into breast milk. A single dose of 50 mg was orally administered in the morning. Milk and blood samples were collected pre-dose and over a period of 72 h after dosing. The pharmacokinetics of daridorexant in milk and plasma were assessed including the cumulative amount and fraction of dose excreted, daily infant dose, and relative infant dose. Safety and tolerability were also investigated. All subjects completed the study. Daridorexant was rapidly absorbed into and distributed from plasma. Daridorexant and its major metabolites were measurable in breast milk. The cumulative total amount of daridorexant excreted over 72 h was 0.010 mg, which corresponds to 0.02% of the maternal dose. This corresponds to a mean daily infant dose of 0.009 mg/day and a relative infant dose of less than 0.22% over 24 h. The maternal safety profile was similar to that observed in previous studies. Low amounts of daridorexant and its metabolites were detected in the breast milk of healthy lactating women. Since the exposure and potential effects on the breastfed infant are unknown, a risk of somnolence or other depressant effects cannot be excluded.

Orexinergic Receptor Antagonists as a New Therapeutic Target to Overcome Limitations of Current Pharmacological Treatment of Insomnia Disorder

Insomnia disorder is a common condition that is considered a risk factor for multiple physical and mental disorders, contributing to reduced quality of life and increased healthcare expenditures. Although cognitive behavioral therapy (CBT) is typically recommended as the primary intervention, its accessibility is hindered by limited resources, prompting the prevalent use of pharmacological interventions as the primary treatment in clinical settings. This study reviews the benefits and risks of current pharmacological treatments for insomnia, with special reference to the orexinergic system as a novel therapeutic target for treatment. The prescription of GABAergic mechanism enhancers (benzodiazepine (BZD) and "Z drugs") has shown efficacy in short-term insomnia treatment (less than 4 weeks), however, concerns arise regarding their long-term effectiveness, unfavorable tolerability and safety profiles, including the potential for dependency. Drugs with antihistamine properties, including certain antidepressants and antipsychotics, exhibit short-term efficacy but have documented tolerability limitations, especially in the elderly. The use of melatonin, available in various formulations, lacks comprehensive long-term data. Dual orexin receptor antagonists (DORAs) such as daridorexant, lemborexant, and suvorexant, represent a novel approach to insomnia treatment by inhibiting wakefulness rather than enhancing sedation. As the only DORA approved for insomnia treatment by the European Medicines Agency (EMA) and Food and Drug Administration (FDA), daridorexant has demonstrated sustained efficacy over a 12-month period, improving nocturnal sleep parameters and daytime functionality, with a favorable safety and tolerability profile.

Early experience with the new DORA daridorexant in patients with insomnia disorder and comorbid mental disturbances: Results of a naturalistic study with 3 months follow-up

Insomnia disorder may affect mental health, increasing suicidal risk. Targeting insomnia is crucial in the clinical practice. Sixty-six consecutive patients with insomnia disorder according with the DSM-5-TR criteria were treated with the dual orexin receptor antagonist, daridorexant 50 mg. Baseline (T0), 1 month (T1) and 3 month (T2) evaluations were performed. Insomnia severity (Insomnia Severity Index), mood, anxiety symptoms and suicidal risk (Beck Depression Inventory-II, Young Mania Rating Scale, Self-Reported Anxiety Scale, Suicidal Ideation Scale), dysfunctional insomnia-cognitive factors and pre-sleep arousal (Dysfunctional Beliefs About Sleep, Pre-Sleep Arousal Scale) were evaluated. The final sample included 66 patients (n = 36, 54% females, mean age 60 ± 13.6 years). Most of them, 64%, suffered from insomnia disorder comorbid with unipolar/bipolar depression, anxiety disorders and substance use disorders. Repeated ANOVA analyses showed that Insomnia Severity Index, Dysfunctional Beliefs About Sleep and Pre-Sleep Arousal Scale total score decreased across time (F = 68.818, p < 0.001; F = 47.561, p < 0.001; F = 28.142, p < 0.001, respectively). Similarly, Beck Depression Inventory-II, Self-Reported Anxiety Scale, Young Mania Rating Scale, and Suicidal Ideation Scale significantly decreased over time (p < 0.001). Predictors of insomnia remission (Insomnia Severity Index < 8) at T1 were improvement of Insomnia Severity Index at T1 (F = 60.205, p < 0.001), and improvement of Dysfunctional Beliefs About Sleep at T1 (F = 4.432, p = 0.041). Insomnia remission at T2 was best predicted by improvement of Dysfunctional Beliefs About Sleep at T2 (F = 3.993, p = 0.023). Multiple-regression models showed that clinical improvement of Beck Depression Inventory-II was best predicted by improvement in Dysfunctional Beliefs About Sleep at T1 and T2, manic symptoms by Insomnia Severity Index at T2, anxiety symptoms by Dysfunctional Beliefs About Sleep, Insomnia Severity Index and somatic Pre-Sleep Arousal Scale at T1 and T2. With the caution of a naturalistic design, early experience with daridorexant showed that by targeting insomnia it may be possible to improve not only insomnia symptoms but also comorbid symptoms.

Clinical safety and narcolepsy-like symptoms of dual orexin receptor antagonists in patients with insomnia: a systematic review and meta-analysis

STUDY OBJECTIVES

Dual orexin receptor antagonists (DORAs) are emerging treatments for insomnia. This meta-analysis study aimed to assess the safety of FDA-approved DORAs (suvorexant, lemborexant, and daridorexant), focusing on narcolepsy-like symptoms associated with these drugs.

METHODS

Five prominent databases were searched to identify randomized controlled trials (RCTs) on this topic. Primary safety outcomes included treatment-emergent adverse events (TEAEs), treatment-related TEAEs, TEAEs leading to discontinuation, and serious TEAEs. Excessive daytime sleepiness (EDS), sleep paralysis, and hallucinations were categorized as adverse events (AEs)-related narcolepsy-like symptoms.

RESULTS

Eleven RCTs with 7703 patients were included. DORAs were associated with a higher risk of TEAEs (risk ratio [RR], 1.09; 95% confidence interval [CI], 1.03 to 1.15) and treatment-related TEAEs (RR, 1.69; 95% CI: 1.49 to 1.92) when compared to placebo. The DORA group exhibited a significantly higher risk of EDS (RR, 2.15; 95% CI: 1.02 to 4.52) and sleep paralysis (RR, 3.40; 95% CI: 1.18 to 9.80) compared to the placebo group.

CONCLUSION

This meta-analysis achieved a comparative evaluation of the clinical safety and tolerability of FDA-approved DORAs for primary insomnia, specifically focusing on AEs-related narcolepsy-like symptoms. This study contributes to understanding the safety profile of FDA-approved DORAs for treating insomnia.

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.

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.

Abuse potential assessment of the dual orexin receptor antagonist daridorexant in rats

BACKGROUND

Drugs that act on the central nervous system (CNS) and have sedative effects can lead to abuse in humans. New CNS-active drugs often require evaluation of their abuse potential in dedicated animal models before marketing approval. Daridorexant is a new dual orexin receptor antagonist (DORA) with sleep-promoting properties in animals and humans. It was approved in 2022 in the United States and Europe for the treatment of insomnia disorder.

AIMS

Nonclinical evaluation of abuse potential of daridorexant using three specific rat models assessing reinforcement, interoception, and withdrawal.

METHODS

Reinforcing effects of daridorexant were assessed in an operant rat model of intravenous drug self-administration. Similarity of interoceptive effects to those of the commonly used sleep medication zolpidem was tested in an operant drug discrimination task. Withdrawal signs indicative of physical dependence were evaluated upon sudden termination of chronic daridorexant treatment. Rat experiments were conducted at a dose range resulting in daridorexant plasma concentrations equaling or exceeding those achieved at the clinically recommended dose of 50 mg in humans.

RESULTS

Daridorexant had no reinforcing effects, was dissimilar to zolpidem in the drug discrimination task, and did not induce any withdrawal-related signs upon treatment discontinuation that would be indicative of physical dependence.

OUTCOMES

Daridorexant showed no signs of abuse or dependence potential in rats. Our data indicate that daridorexant, like other DORAs, has a low potential for abuse in humans.

Daridorexant: Comprehensive Review of A New Oral Agent for the Treatment of Insomnia

OBJECTIVE

To review the current pharmacology, pharmacokinetics/pharmacodynamics, safety, and efficacy of daridorexant in patients with insomnia.

DATA SOURCES

A literature search of PubMed (March 1, 2018, to October 19, 2022) and ClinicalTrials.gov search was conducted using the following terms: daridorexant and ACT-541468. Additional articles were identified by hand from references.

STUDY SELECTION AND DATA EXTRACTION

We included English-language articles evaluating daridorexant pharmacology, efficacy, or safety in humans for the management of insomnia.

DATA SYNTHESIS

Daridorexant has a peak plasma concentration of 1-2 hours, terminal half-life of 8 hours, and absolute bioavailability of 61%. Wake after sleep onset (WASO) significantly decreased from baseline to months 1 and 3 in daridorexant 25 (-18.40 and -22.97 min, P < 0.0001) and 50 mg (-28.98 and -29.41 min, P < 0.0001) groups compared with placebo. Latency to persistent sleep (LPS) significantly decreased from baseline to months 1 and 3 for daridorexant 25 mg (-28.17 and -30.73 min, P = 0.0005 and P = 0.0015) and 50 mg (-31.20 and -34.80 min, P < 0.0001).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING AGENTS

Daridorexant can be administered in diverse patient populations because of its tolerability and favorable safety profile. However, due to the lack of large scale studies that directly compare dual orexin receptor antagonists (DORAs), there is not enough data to recommend 1 DORA over another.

CONCLUSIONS

Daridorexant is well tolerated and has demonstrated significant reductions in LPS and WASO in the treatment of insomnia in adult patients.

Different doses of dual orexin receptor antagonists in primary insomnia: a Bayesian network analysis

Background: Systematic comparisons of the doses of the Food and Drug Administration (FDA)-approved dual orexin receptor antagonists (DORAs) for people with insomnia are limited. Methods: PubMed, Embase, Cochrane Library, and Clinicaltrials. gov were systematically searched to identify relevant studies published before 31 October 2022. We assessed the certainty of evidence using the confidence in network meta-analysis (CINeMA) framework. Results: We pooled 7257 participants from 9 randomized controlled trials (RCTs). Moderate to high certainty evidence demonstrated suvorexant (20 and 40 mg) and daridorexant (10 and 50 mg) as the most effective in latency to persistent sleep (LPS) reduction. Lemborexant at 5 and 10 mg was the most effective in subjective sleep onset time (sTSO) reduction. For wake time after sleep onset (WASO), all drugs except daridorexant 5 mg were more effective than placebo. Lemborexant 5 mg was among the best in subjective WASO (sWASO) (moderate to high certainty) and had the highest surface under the curve ranking area (SUCRA) values for sWASO (100%). For total sleep time (TST), suvorexant and daridorexant, except the respective minimum doses, were more effective than placebo, while suvorexant 40 mg and lemborexant 10 mg may have been the most effective for subjective TST (sTST) (low to very low certainty). Suvorexant 40 mg (RR 1.09), suvorexant 80 mg (RR 1.65), and daridorexant 25 mg (RR 1.16) showed a higher safety risk than placebo. Conclusion: Suvorexant 20 mg, lemborexant 5 mg, lemborexant 10 mg, and daridorexant 50 mg represent suitable approaches for insomnia. Clinical Trial Registration: clinicaltrials.gov, PROSPERO (CRD42022362655).

Use of Daridorexant among Patients with Chronic Insomnia: A Retrospective Observational Analysis

Insomnia is the most prevalent sleep disorder, affecting millions worldwide and taking a heavy toll on patient health with significant social and economic impact. Even though there are multiple different types of insomnia medications and behavioral therapies, there are still many individuals for whom treatment remains ineffective. The objective of this retrospective study was to analyze the effectiveness of daridorexant in a cohort of chronic insomnia patients largely transitioned from GABA-A positive allosteric modulators (benzodiazepines, zolpidem or eszopiclone) or other frequently prescribed insomnia medications (including trazodone, atypical antipsychotics or tricyclic antidepressants). A total of 86 patients were treated in the course of ordinary practice and the primary analytic endpoint was the change in Insomnia Severity Index (ISI) score following ≥ 30 nights of treatment with daridorexant. Results from 80 of the 86 patients with full data (65% female, mean age 53.5 years, 18.8% with comorbid obstructive sleep apnea, 91.3% transitioned from a different medication) showed a mean improvement in ISI score of 7.0 ± 0.54 points (SEM) (p < 0.0001) from 18.0 to 11.0. Overall, 78% of the cohort demonstrated a clinically meaningful improvement as defined by at least a six-point drop in ISI. Total sleep time increased by 54 ± 1.0 min (SEM) (p < 0.0001) from 6.0 h to 6.9 h. Mean sleep latency decreased by 23.9 ± 2.4 min (SEM) (p < 0.0001) from 58.8 min to 34.9 min. Wake after sleep onset decreased by 31.6 ± 3.2 min (SEM) (p < 0.001) from 42.8 min to 11.3 min. Sleep efficiency improved by 10.5 ± 1.1% (SEM) (p < 0.0001) from 79.3% to 89.8%. No significant adverse events were noted during the study duration. Keeping in mind this study's limitations, these data suggest that for insomnia patients with an incomplete response to current therapy, switching to daridorexant is safe and may be an effective alternative treatment.

The Metabolism of the Dual Orexin Receptor Antagonist Daridorexant

Daridorexant is a dual orexin receptor antagonist developed for the treatment of insomnia disorder and has shown improvement in sleep outcomes and daytime functioning. The present work describes its biotransformation pathways in vitro and in vivo and provides a cross-species comparison between the animal species used in preclinical safety assessments and man.Daridorexant clearance is driven by metabolism along seven distinct pathways. Metabolic profiles were characterized by downstream products while primary metabolic products were of minor importance. The metabolic pattern differed between rodent species, with the rat reflecting the human pattern better than the mouse.In rodents, daridorexant is mostly excreted via the bile after extensive metabolism while urinary excretion was negligible in the rat. Only traces of parent drug were detected in urine, bile or faeces.Daridorexant has three major metabolites which are well covered in these preclinical safety species. All of them retain some residual affinity towards orexin receptors. However, none of these is considered to contribute to the pharmacological effect of daridorexant as their active concentrations in human brain are too low.

Daridorexant for the treatment of insomnia disorder: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Daridorexant is a novel dual orexin receptor antagonist that has shown efficacy as a treatment for insomnia in multiple randomized clinical trials. However, the efficacy and safety of daridorexant for treatment of insomnia disorder has not been characterized comprehensively in the literature. Therefore, we performed a meta-analysis of available studies. We performed a meta-analysis to systematically evaluate the efficacy and safety of daridorexant for treatment of insomnia disorder.

METHODS

MEDLINE, Embase, Cochrane Library, and Clinicaltrials.gov for randomized controlled trials were systematically searched up to February 2022. Relative risk and standard mean difference were used to evaluate clinical outcomes.

RESULTS

We pooled 2271 patients from 4 randomized clinical trials, and evaluated efficacy endpoints. We found that 50 mg of daridorexant was superior to placebo for 4 efficacy outcomes including wake time after sleep onset, latency to persistent sleep, subjective total sleep time, and Insomnia Daytime Symptoms and Impacts Questionnaire domain score (P < .05). In addition, there were no significant differences (P > .05) in adverse events between daridorexant and placebo.

CONCLUSIONS

Different dosages of daridorexant were tested for treatment of insomnia; however, 5 and 10 mg are not available because of issues of suboptimal effectiveness. Daridorexant showed better efficacy and safety for treatment of insomnia disorder at doses of 25 and 50 mg.

Daridorexant: A New Dual Orexin Receptor Antagonist for Insomnia

Objective: To review the safety, efficacy, and tolerability of daridorexant in treating insomnia characterized by difficulties with sleep onset and/or sleep maintenance in adult patients. Data Sources: A literature search was performed through PubMed using the following key terms: daridorexant, ACT-541468, orexin, insomnia, and sleep. Study Selection and Data Extraction: Selected articles included those which described clinical studies of the pharmacokinetics, efficacy, safety, or tolerability of daridorexant. Data Synthesis: Daridorexant works through antagonism of the dual orexin receptor. It is the third agent in this class of medications approved by the U.S. Food and Drug Administration (FDA). Daridorexant, at a dose of 25 mg to 50 mg, was shown to be effective in improving sleep parameters in phase 3 clinical studies and was well tolerated. Adverse event rates from phase 2 and 3 clinical trials were low with fatigue, nasopharyngitis, gait disturbance, somnolence, diarrhea, and headache most commonly reported. Conclusions: All currently available agents for treating insomnia have received a "weak" recommendation in the clinical practice guidelines, including the dual orexin receptor antagonist class of medications. Initial data suggest that with routine use daridorexant does not impair next day functioning, a common issue with other agents used to treat insomnia. In addition, daridorexant appears to be as safe and effective in treating insomnia in patients of all ages including those ≥65 years of age.

A Comprehensive Review of Daridorexant, a Dual-Orexin Receptor Antagonist as New Approach for the Treatment of Insomnia

Insomnia affects 4.4-4.8% of the world's population, but because the effect of hypnotic drugs is limited and may cause harmful side-effects, scientists are turning their attention to developing drugs that act on the orexin system. Daridorexant, a selective dual-orexin receptor antagonist (DORA), has exhibited promising results in both animal and human studies. Its activity was evaluated based on the physiology-based pharmacodynamic and pharmacokinetic model. The use of daridorexant is considered safe, with no clinically significant side-effects including deprivation of next-morning residual effects. In this manuscript we conducted a comprehensive review of daridorexant including pharmacodynamics, animal and human research, pharmacokinetics and safety.

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.

Abuse potential assessment of the new dual orexin receptor antagonist daridorexant in recreational sedative drug users as compared to suvorexant and zolpidem

STUDY OBJECTIVES

Abuse potential properties have been reported for the dual orexin receptor antagonists (DORAs) suvorexant and lemborexant. Daridorexant is a new DORA currently in late-stage clinical development. This randomized, double-blind, double-dummy, placebo- and active-controlled 6-period crossover study assessed its abuse potential in healthy recreational sedative drug users (n=63).

METHODS

In each study period, a single, oral, morning dose of either daridorexant (50, 100, 150 mg), placebo, or active control, i.e., suvorexant (150 mg) or zolpidem (30 mg), was administered. Primary pharmacodynamic endpoint was the Emax of the Drug-liking visual analog scale (VAS) assessed over 24 h. Several secondary subjective and objective pharmacodynamic endpoints were also assessed.

RESULTS

Study validity was confirmed based on drug-liking of suvorexant and zolpidem greater than placebo applying a pre-defined 15-point validity margin (p<0.0001). Drug-liking VAS Emax (mean; 95% CI) of daridorexant at 50 mg (73.2; 69.0-77.5) was significantly lower compared to suvorexant (80.7; 77.0-84.5) and zolpidem (79.9; 76.2-83.5) (p<0.001), but similar at 100 mg (79.1; 75.0-83.3) and 150 mg (81.3; 77.7, 84.8). Such dose-related patterns were also observed for most secondary endpoints. At each daridorexant dose, Drug-liking VAS scores were greater than placebo. Both control drugs and daridorexant were safe and the pharmacokinetics of daridorexant was consistent with earlier trials indicating quick absorption and elimination.

CONCLUSIONS

In this large, valid human abuse potential study, daridorexant showed dose-related drug-liking among recreational sedative drug users with lower effects at the highest phase-3 dose, and similar effects at higher doses compared to supratherapeutic doses of suvorexant and zolpidem.

Effect of the new dual orexin receptor antagonist daridorexant on nighttime respiratory function and sleep in patients with mild and moderate obstructive sleep apnea

In this randomized, double-blind, placebo-controlled, two-period crossover study, the effect of the dual orexin receptor antagonist daridorexant was evaluated on nighttime respiratory function and sleep in 28 patients with mild and moderate obstructive sleep apnea (OSA). In each period, 50 mg daridorexant or placebo was administered every evening for 5 days. The primary endpoint was apnea/hypopnea index (AHI) during total sleep time (TST) after the last dosing. Other endpoints included peripheral oxygen saturation (SpO2), sleep duration, latency to persistent sleep (LPS), wake after sleep onset (WASO), and sleep efficiency index (SEI). Pharmacokinetics, safety, and tolerability were also assessed. The mean treatment difference for AHI during TST (i.e. daridorexant - placebo) after the last dosing was 0.74 events/hour (90% confidence interval [CI]: -1.43, 2.92). The corresponding treatment difference for SpO2 during TST was 0.16% [90% CI: -0.21, 0.53]. Overall, there was no clinically relevant effect of daridorexant on AHI or SpO2-related data after single and repeated dosing irrespective of sleep phase (i.e. rapid eye movement [REM] vs non-REM). Moreover, after single and repeated dosing, daridorexant prolonged TST by 39.6 minutes (90% CI: 16.9, 62.3) and 38.8 minutes (19.7, 57.9), respectively, compared with placebo and favorably modulated other sleep-related endpoints (i.e. increased SEI, decreased WASO, and shortened LPS). It attained expected plasma concentrations and was well tolerated in patients with mild and moderate OSA. These results indicate that single and repeated doses of 50 mg daridorexant do not impair nighttime respiratory function and improve sleep in patients with mild and moderate OSA. Clinical Trial Registration: ClinicalTrials.gov NCT03765294. A study to investigate the effects of ACT-541468 on nighttime respiratory function in patients with mild to moderate obstructive sleep apnea. https://clinicaltrials.gov/ct2/show/ NCT03765294.

The dual orexin receptor antagonist daridorexant does not affect the pharmacokinetics of the BCRP substrate rosuvastatin

Daridorexant is a dual orexin receptor antagonist in clinical development for the treatment of insomnia. Breast-cancer resistant protein (BCRP) is an efflux pump expressed in intestinal epithelium and hepatocytes, contributing to the absorption, distribution, and elimination of drugs and endogenous compounds. In vitro, daridorexant inhibits BCRP with an IC₅₀ of 3.0 μmol/L. The BCRP substrate rosuvastatin is a cholesterol-lowering drug, recommended for clinical drug-drug interaction (DDI) studies. In order to exclude an inhibitory effect of daridorexant on BCRP, this single-centre, open-label, two-treatment Phase 1 study investigated the effect of daridorexant at steady state on the pharmacokinetics (PK) of single-dose rosuvastatin in 20 healthy male subjects. In addition, safety and tolerability were assessed. A single oral dose of 10 mg rosuvastatin on Day 1 was followed by 96 hours observation. Thereafter, 25 mg daridorexant was administered once daily (o.d.) on Days 5-8 and in combination with 10 mg rosuvastatin on Day 8. On Days 9-12, subjects received 25 mg daridorexant alone. PK sampling was performed up to 120 hours after treatment administration. The results showed that concomitant administration of 25 mg daridorexant o.d. at steady state did not affect the exposure parameters of rosuvastatin in a relevant way, as indicated by the ratios of geometric means (GMRs) ([rosuvastatin + daridorexant]/[rosuvastatin alone]) of 0.93 for both C_max and AUC_0-∞ . Administration of a single dose of 10 mg rosuvastatin, multiple doses of 25 mg daridorexant alone or in combination were well tolerated. Taken together, daridorexant and BCRP substrates can be safely co-administered.