Meaningful Within-Patient Change in Subjective Total Sleep Time in Patients with Insomnia Disorder: An Analysis of the Sleep Diary Questionnaire Using Data from Open-Label and Phase III Clinical Trials

BACKGROUND

The Sleep Diary Questionnaire (SDQ), a modified version of the Consensus Sleep Diary, is a 17-item sleep diary for assessing subjective total sleep time (sTST: total time spent asleep at night) and other sleep parameters in insomnia trials. sTST is a key parameter of efficacy in insomnia trials; however, the magnitude of improvement in this parameter that people with insomnia disorder consider clinically meaningful is unclear.

OBJECTIVE

The aim of this study was to estimate meaningful within-patient change for sTST using clinical trial data.

METHODS

Data were from an open-label trial of zolpidem and pooled data from a phase III placebo-controlled trial of daridorexant. In both trials, adults with moderate to severe insomnia completed the SDQ daily. Meaningful change in sTST was estimated in an anchor-based analysis using outcome measures that were correlated with change in weekly average sTST (Spearman correlation coefficient ≥ 0.30): the Insomnia Severity Index, patient global assessments and impressions of severity and change in daytime and night-time symptoms (PGA-S, PGI-S, PGI-C), and clinician global impressions of severity and change in patients' daytime symptoms (CGI-S, CGI-C). Meaningful within-patient change estimates were 'triangulated' to identify a value where they converged.

RESULTS

In the open-label trial (N = 114), subjects with a 1-point or 1-step improvement on the anchors had mean increases in sTST of 60.1-83.2 min at day 8 and 55.5-68.2 min at day 15. For subjects with a 2-point or 2-step improvement on the anchors, mean increases in sTST were 79.6-81.4 min at day 8 and 80.1-93.5 min at day 15. In the phase III trial (N = 930), weekly average increases in sTST for subjects with a 1-point or 1-step improvement on the anchors were 39.3-46.7 min at month 1 and 47.3-58.3 min at month 3. For subjects with a 2-point or 2-step improvement on the anchors, mean increases in sTST were 60.7-76.2 min at month 1 and 70.1-87.7 min at month 3. Triangulation of these values supported a meaningful within-patient change threshold starting at 55 min.

CONCLUSION

Increasing sTST is an important treatment outcome for people with insomnia. An increase in sleep time of approximately 55 min is meaningful to patients.

CLINICAL TRIALS REGISTRATION

NCT03056053 (17 February 2017) and NCT03545191 (4 June 2018).

Number, Duration, and Distribution of Wake Bouts in Patients with Insomnia Disorder: Effect of Daridorexant and Zolpidem

BACKGROUND

Daridorexant, a dual orexin receptor antagonist approved in early 2022, reduces wake after sleep onset without reducing the number of awakenings in patients with insomnia. The objective of this post hoc analysis was to explore the effect of daridorexant on the number, duration, and distribution of night-time wake bouts, and their correlation with daytime functioning.

METHODS

Adults with insomnia disorder were randomized 1:1:1:1:1:1 to placebo, zolpidem 10 mg, or daridorexant 5, 10, 25, or 50 mg in a phase II dose-finding study, and 1:1:1 to placebo or daridorexant 25 or 50 mg in a pivotal phase III study. We analyzed polysomnography data for daridorexant 25 and 50 mg, zolpidem 10 mg, and placebo groups. Polysomnography was conducted at baseline, then on Days 1/2, 15/16, and 28/29 in the phase II study, and Months 1 and 3 in the phase III study. The number, duration, and distribution of wake bouts (≥ 0.5 min) were assessed.

RESULTS

Data from 1111 patients (phase II study: daridorexant 50 mg [n = 61], zolpidem 10 mg [n = 60], placebo [n = 60]; phase III study: daridorexant 25 mg [n = 310], daridorexant 50 mg [n = 310], placebo [n = 310]) were analyzed. Long wake bouts were defined as > 6 min. Compared with placebo, daridorexant 50 mg reduced overall wake time (p < 0.05; all time points, both studies), the odds of experiencing long wake bouts (p < 0.001; Months 1 and 3, phase III study), and the cumulative duration of long wake bouts (p < 0.01; all time points, both studies). Reductions in long wake bouts were sustained through the second half of the night and correlated with improvements in daytime functioning. An increase in the cumulative duration of short wake bouts was observed with daridorexant 50 mg (p < 0.01 vs placebo, Months 1 and 3, phase III study); this was uncorrelated with daytime functioning.

CONCLUSION

Daridorexant reduced the number and duration of longer wake bouts throughout the night compared with placebo, corresponding with improved daytime functioning.

CLINICAL TRIALS

Clinicaltrials.gov NCT02839200 (registered July 20, 2016), NCT03545191 (registered June 4, 2018).

Meaningful Within-Patient Change on the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ): Analysis of Phase III Clinical Trial Data of Daridorexant

BACKGROUND

The Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ) is a new validated 14-item patient-reported outcome (PRO) instrument for evaluating daytime functioning in people with insomnia. It comprises three domains: Alert/Cognition, Mood, and Sleepiness.

OBJECTIVE

The aim of this analysis was to estimate the minimum within-patient change for IDSIQ scores that an adult patient with insomnia would consider meaningful.

METHODS

Data were from a randomized, double-blind, placebo-controlled, phase III clinical trial of daridorexant in adults with insomnia. Subjects completed the IDSIQ daily in the evening, with a recall period of 'today', throughout the 3-month double-blind treatment period. Scores were calculated as a weekly average. Each IDSIQ item was scored on an 11-point numeric rating scale ranging from 0 (not at all/none at all) to 10 (very/a lot), with a higher score indicating a greater severity or impact. PRO measures with correlation coefficients ≥0.30 were included in a subsequent anchor-based analysis. For the IDSIQ total score and each IDSIQ domain, meaningful within-patient change was estimated as the minimum score change patients would consider meaningful in an anchor-based analysis using data from PRO instruments capturing daytime and night-time insomnia symptoms (the Insomnia Severity Index [four items, each scored 0-4, with a higher score indicating greater symptom severity; assessed at screening, baseline, month 1 and month 3], Patient Global Assessment of Disease Severity [6-point scale from 'none' to 'very severe'; assessed weekly], Patient Global Impression of Severity [4-point scale from 'none' to 'severe'; assessed weekly], and Patient Global Impression of Change [7-point scale from 'very much better' to 'very much worse'; assessed weekly for night-time and daytime symptoms separately]). A supplemental distribution-based analysis was also conducted to support the anchor-based analysis.

RESULTS

The analysis included 930 subjects aged 18-88 years. Spearman correlation coefficients for the relationships between score changes/ratings for anchors and the IDSIQ (0.36-0.44 at month 1, 0.45-0.57 at month 3) were all above the prespecified threshold of 0.30. Mean IDSIQ score changes at months 1 and 3 based on the different anchors supported meaningful within-patient change estimates starting at 17 points for the IDSIQ total score, 9 points for the Alert/Cognition domain, and 4 points for the Mood and Sleepiness domains.

CONCLUSION

This analysis demonstrates the meaningful within-patient change for the IDSIQ total score and domain scores, that the instrument is sensitive to changes in the patient experience of insomnia, and that it can be used in clinical trials to evaluate changes in daytime functioning.

CLINICAL TRIALS REGISTRATION

NCT03545191 (4 June 2018).

Summary of Research: Development and Validation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ)

This is a summary of the original article 'Development and Validation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ)'. Individuals with insomnia are best positioned to assess the impact of insomnia on their quality of life. Patient reported outcomes (PROs) are self-reported health measures created to allow people to record their experience of their disease. Chronic insomnia has a major impact on daytime functioning for patients, and on their quality of life. This summary of research provides an overview of a previously published article detailing the development and evaluation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ), as a tool to allow people with insomnia to report their experience of the impact on their daytime functioning.

Long-Term Safety and Tolerability of Daridorexant in Patients with Insomnia Disorder

BACKGROUND AND OBJECTIVE

Daridorexant is a dual orexin receptor antagonist for the treatment of insomnia. In two phase III, 12-week studies in patients with insomnia disorder, daridorexant improved sleep and daytime functioning while maintaining a favorable safety profile. The objective of this 40-week extension study was to assess the long-term safety and tolerability of daridorexant.

METHODS

Adults with insomnia disorder who completed the 12-week studies were invited to enroll in this double-blind extension study. Patients originally randomised to daridorexant (10 mg/25 mg/50 mg) remained on their respective treatments; patients randomised to placebo were re-randomised to daridorexant 25 mg or placebo. The 40-week treatment period was followed by a 7-day placebo run-out. The primary objective was to assess safety/tolerability. Exploratory objectives were to evaluate the efficacy of daridorexant on sleep (self-reported total sleep time) and daytime functioning (Insomnia Daytime Symptoms and Impacts Questionnaire).

RESULTS

In total, 804 patients were enrolled in the study, of whom 801 received at least one dose of the study treatment and 550 patients (68.4%) completed the study. Overall incidence of treatment-emergent adverse events was similar across groups (35-40%). Daridorexant did not induce next-morning sleepiness and no withdrawal-related symptoms or rebound were observed after treatment discontinuation. Improvements in sleep and daytime functioning were maintained through to the end of the study and were most pronounced with daridorexant 50 mg. Daridorexant 50 mg, compared with placebo, increased self-reported total sleep time by a least-squares mean of 20.4 (95% confidence interval [CI] 4.2, 36.5), 15.8 (95% CI - 0.8, 32.5) and 17.8 (95% CI - 0.4, 35.9) minutes and decreased (i.e., improved) Insomnia Daytime Symptoms and Impacts Questionnaire total scores by a least-squares mean of - 9.3 (95% CI - 15.1, - 3.6), - 9.5 (95% CI - 15.4, - 3.5) and - 9.1 (95% CI - 15.6, - 2.7), at weeks 12, 24 and 36 of the extension study, respectively.

CONCLUSIONS

Treatment with daridorexant, for up to 12 months, was generally safe and well tolerated. Exploratory efficacy analyses suggest that the sustained improvements in sleep and daytime functioning with daridorexant 50 mg support its use for long-term treatment of insomnia disorder, without concerns of new safety signals.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT03679884) [first posted: 21 September, 2018], https://clinicaltrials.gov/ct2/show/NCT03679884 .

Efficacy and Safety of Daridorexant in Older and Younger Adults with Insomnia Disorder: A Secondary Analysis of a Randomised Placebo-Controlled Trial

Background and Objective

The dual orexin receptor antagonist daridorexant, studied in two phase III trials, dose-dependently improved objective and subjective sleep variables and daytime functioning in adults with insomnia. Because treatment of insomnia in older adults is challenging and has limited options, the purpose of the current analysis was to further analyse the phase III trial studying the higher doses of daridorexant, those that showed efficacy (daridorexant 50 mg, daridorexant 25 mg and placebo, nightly for 3 months), and compare the safety and efficacy of daridorexant in patients aged ≥ 65 (‘older adults’) to those aged < 65 years (‘younger adults’).

Methods

Analyses by age (≥ 65 years, n = 364; < 65 years, n = 566) were performed on data from the randomised, double-blind, placebo-controlled Trial 1 in adult patients with insomnia (NCT03545191). Efficacy endpoints included a change from baseline at month 1 and month 3 in polysomnography-measured wake after sleep onset (WASO) and latency to persistent sleep (LPS), self-reported total sleep time (sTST) and daytime functioning assessed using the validated Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ). Safety endpoints included adverse events and the Visual Analog Scale for morning sleepiness.

Results

At baseline, mean [standard deviation] WASO was numerically greater (110 [39] vs 92 [38] min) in older than younger adults, while LPS was comparable (~ 65 min). Mean baseline IDSIQ total and all domain scores were numerically lower (i.e. better) in older adults. Daridorexant caused similar reductions in WASO and LPS, and similar increases in sTST, from baseline, in both age groups; improvements were numerically greater with daridorexant 50 mg than 25 mg. At month 3, daridorexant 50 mg, compared with placebo, decreased WASO by a least-squares mean of 19.6 (95% confidence interval 9.7, 29.5) in older patients versus 17.4 min (10.7, 24.0) in younger patients and decreased LPS by a least-squares mean of 14.9 (7.5, 22.3) in older patients versus 9.7 min (3.7, 15.7) in younger patients. Daridorexant 50 mg increased sTST from baseline to month 3 by a least-squares mean of 59.9 (49.6, 70.3) in older patients versus 57.1 min (48.9, 65.3) in younger patients. Daridorexant 50 mg progressively improved IDSIQ total and domain scores from week 1 onwards similarly in both groups; daridorexant 25 mg improved IDSIQ scores, but only in younger adults. In both age groups, in comparison with placebo, the overall incidence of adverse events was comparable, and there were fewer falls on daridorexant. Daridorexant improved Visual Analog Scale morning sleepiness in both groups; daridorexant 50 mg increased the mean (standard deviation) Visual Analog Scale morning sleepiness score by 15.9 (20.7) in older adults and by 14.9 (18.7) in younger adults from baseline to month 3. In older adults, there was one case of sleep paralysis, and no cases of narcolepsy, cataplexy, or complex sleep behaviour.

Conclusions

In older patients with insomnia, as in younger patients, the efficacy of daridorexant is maximal on night-time and daytime variables at the higher dose of 50 mg. Older patients particularly require this dose to improve daytime functioning. Older patients are not at an increased risk of adverse events or residual effects the next morning after night-time administration of daridorexant, even at 50 mg. The dose of daridorexant does not need to be decreased for older patients.

Clinical Trial Registration

ClinicalTrials.gov (NCT03545191) [first posted: 4 June, 4 2018], https://clinicaltrials.gov/ct2/show/NCT03545191.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40266-022-00977-4.

The burden of chronic insomnia (difficulty in falling/staying asleep or not getting enough sleep) increases with age yet treatment options in older patients are limited. In older patients, because of a risk of side effects, guidelines suggest caution when prescribing sleep medications and, for some drugs, recommend starting at a lower dose. Daridorexant was approved in 2022 for the treatment of insomnia in adults following positive results in two trials that showed daridorexant significantly improved night-time sleep and daytime functioning over 3 months of treatment in adults with insomnia. Approximately 40% of patients taking part in these trials were aged 65 years or older. This current analysis compared the safety and benefits of daridorexant in older adults (aged at least 65 years) and younger adults (aged less than 65 years) in the trial that administered the highest two doses of daridorexant, 25 and 50 mg. The results showed that the benefits of daridorexant were comparable in both age groups over 3 months; compared with placebo, daridorexant improved night-time sleep (reduced time awake during the night, reduced time to fall asleep and increased total sleep time) and daytime functioning—patients had less daytime sleepiness and a better mood and feeling of alertness. In older patients, the benefits, particularly for daytime functioning, were greatest at the higher 50-mg dose, without any increase in side effects. Both doses of daridorexant were equally well tolerated in the two age groups, indicating that treatment with daridorexant at 50 mg can be safely started in older patients.

Preferences of patients for benefits and risks of insomnia medications using data elicited during two phase III clinical trials

Study Objectives

To elicit the trade-offs patients are willing to make between benefits and risks of medications for chronic insomnia, with the purpose of allowing a patient-centric interpretation of clinical trial data.

Methods

A discrete choice experiment (DCE) was included in the two placebo-controlled phase III trials that evaluated the efficacy and safety of daridorexant. The DCE design was informed by a two-phase qualitative study, followed by qualitative and quantitative pilot testing before fielding. Relative attribute importance (RAI) and acceptable trade-offs between benefits and risks were obtained using a mixed logit model.

Results

Preferences were elicited from 602 trial participants (68.1% female, aged 58.6 ± 14.5 years). Preferences were most affected by daytime functioning (RAI = 33.7%) as a treatment benefit and withdrawal symptoms (RAI = 27.5%) as a risk. Patients also valued shorter sleep onset (RAI = 6.4%), longer sleep maintenance (RAI = 5.4%), reduced likelihood of abnormal thoughts and behavioral changes (RAI = 11.3%), reduced likelihood of dizziness/grogginess (RAI = 9.2%), and reduced likelihood of falls at night (RAI = 6.5%). Patients were willing to make trade-offs between these attributes. For example, they would accept an additional 18.8% risk of abnormal thoughts and behavioral changes to improve their daytime functioning from difficult to restricted and an additional 8.1% risk of abnormal thoughts and behavioral changes to avoid moderate withdrawal effects.

Conclusions

Patients with insomnia were willing to make trade-offs between multiple benefits and risks of pharmacological treatments. Because patients valued daytime functioning more than sleep latency and duration, we recommend that functional outcomes and sleep quality be considered in treatment development and evaluation.

0455 The Insomnia Daytime Symptoms and Impacts Questionnaire: An Analysis of Clinically Meaningful Change Using Phase 3 Clinical Trial Data

Introduction

The Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ) is a new validated patientreported outcome (PRO) instrument evaluating daytime functioning in people with insomnia. It comprises 14 items grouped into 3 domains: Alert/Cognition, Mood, and Sleepiness. To further explore the ability of the IDSIQ to capture clinically meaningful changes in daytime functioning resulting from treatment, we estimated withinsubject changes in IDSIQ scores using phase 3 trial data.

Methods

A randomized double-blind placebocontrolled trial of daridorexant in adults with insomnia (NCT03545191), in which subjects completed the IDSIQ daily during treatment, provided data for blinded analyses. Spearman correlations were calculated for changes in IDSIQ scores and potential anchors: Insomnia Severity Index, Patient Global Assessment of Disease Severity, Patient Global Impression of Severity, and Patient Global Impression of Change, applying a prespecified threshold of 0.30 (moderate association). Anchor-based analyses of weekly average IDSIQ total and domain scores were used to estimate responder definitions (RDs). The various RD estimates were triangulated to identify values where they converged. Distribution-based and receiver operating characteristic analyses calculated standard error of measurement (SEM), 0.5 standard deviation (SD), and Youden’s index as supportive evidence for anchor-based RD estimates.

Results

The analysis included 930 subjects (18-88 years). Score change correlations for the potential anchors and IDSIQ at month 1 (0.36–0.44) and month 3 (0.45–0.57) were all &gt;0.30. Triangulation of mean IDSIQ score changes in subjects with clinically relevant improvement on the different anchors supported RD thresholds for clinically meaningful change of 17 points for the IDSIQ total score, 9 points for the Alert/Cognition domain, 4 points for the Mood domain, and 4 points for the Sleepiness domain. SEM and 0.5 SD values were within the ranges of anchor-based IDSIQ score changes, and Youden’s index was maximized or near-maximized when the RD estimates were used as thresholds for identifying responders based on the anchors.

Conclusion

The IDSIQ is sensitive to changes in patients who experience daytime impacts of insomnia and can be used to assess treatment efficacy on daytime functioning in patients with insomnia.

Support (If Any)

This work was funded by Idorsia Pharmaceuticals Ltd.

347 Daridorexant is Safe and Improves Both Sleep and Daytime Functioning in Elderly Patients with Insomnia

Introduction

Insomnia affects elderly more than younger adults, and comorbidities more prevalent in elderly populations can add to symptom burden and reduce therapeutic options. Drugs that improve insomnia symptoms with limited safety risks are needed to treat this patient group. We report elderly subgroup analyses from a Phase-3 registration trial with daridorexant.

Methods

In this multi-center, double-blind trial (NCT03545191), adult (18–64y) and elderly (≥65y) patients with insomnia were randomized (1:1:1) to receive oral daridorexant 25mg, 50mg or placebo every evening for 3 months. Month 3 endpoints were: change from baseline in polysomnography-measured wake-after-sleep-onset (WASO) and latency-to-persistent-sleep (LPS) (both primary endpoints), subjective total sleep time (sTST), and daytime functioning (Insomnia Daytime Symptoms and Impacts Questionnaire [IDSIQ] – sleepiness domain; with a lower score indicating improved daytime functioning). Safety endpoints included treatment emergent adverse events (TEAE), AEs of special interest (AESI; symptoms related to excessive daytime sleepiness or complex sleep behavior, and suicidal ideation/self-injury) and withdrawal effects upon treatment cessation (assessed by the Benzodiazepine Withdrawal Symptom Questionnaire total score and relevant AEs).

Results

Of the 930 patients randomized, 364 (39.1%) were ≥65y: daridorexant 25mg (n=121), 50mg (n=121) and placebo (n=122). In this subgroup, at Month 3, the placebo-corrected least-square mean of change from baseline [95%CL] for daridorexant 25mg and 50mg were: WASO -17.0[-27.0,-7.0] and -19.6[-29.5,-9.7] mins; LPS -7.8[-15.2,-0.4] and -14.9[-22.3,-7.5] mins; sTST 18.7[4.1,33.2] and 30.6[16.1,45.2] mins; IDSIQ sleepiness domain -0.6[-2.2,0.9] and -2.6[-4.1,-1.0], all respectively. TEAEs were reported in 32.2%, 35.3%, and 31.1% of patients ≥65y in the 25mg, 50mg and placebo groups, respectively. Falls (n=1,1,4 for 25mg, 50mg, placebo, respectively) and dizziness (n=4,1,1), both of particular interest in elderly, were least frequent in the 50mg group. Compared to placebo, somnolence was as frequent for 50mg daridorexant (n=6,1,1) while fatigue was more frequent in both daridorexant groups (n=4,3,1); incidence did not appear dose-related. AESI, of mild intensity, were reported in 2 patients ≥65y (one in each daridorexant group). There was no evidence of withdrawal symptoms.

Conclusion

Daridorexant is efficacious in the elderly population for improvements in sleep and daytime functioning. No safety concerns in this vulnerable population were identified at either dose.

Support (if any)

Funded by Idorsia Pharmaceuticals Ltd.

344 Daridorexant Improves Total Sleep Time (TST) in Insomnia Patients Without Altering the Proportion of Sleep Stages

Introduction

Daridorexant, a new dual orexin receptor antagonist, improved sleep parameters and daytime functioning in two pivotal Phase 3 trials in patients with insomnia (Trial-1, NCT03545191; Trial-2, NCT03575104); polysomnography data were collected at multiple timepoints from &gt;1,800 patients. We report the effects of daridorexant on TST and sleep stages from both trials.

Methods

Eligible patients with insomnia (according to DSM-5) were randomized (1:1:1) in Trial-1 (N=930) to daridorexant 25mg, 50mg, or placebo and in Trial-2 (N=924) to daridorexant 10mg, 25mg, or placebo. Oral treatment was administered each night during a 3-month double-blind treatment period. Assessment of TST and sleep stages (non-rapid eye movement [NREM, N]1, N2, N3, REM), measured by polysomnography in sleep laboratory, was performed on two consecutive nights during single-blind placebo run-in (baseline) and Months 1 and 3 (M1 and M3) of double-blind treatment. Change from baseline in TST and sleep stages were exploratory endpoints in both trials. Data for M3 (mean ± standard deviation) are presented as change from baseline.

Results

Daridorexant dose-dependently increased TST(minutes) from baseline to M3, more than placebo, in Trial-1 (25mg, 55±56; 50mg, 61±53; placebo, 40±56) and Trial-2 (10mg, 37±57; 25mg, 50±53; placebo, 35±56). In both trials, sleep stage proportions were preserved from baseline to M3, with no relevant changes in any group. Baseline time spent in each sleep stage (% of TST) was consistent across groups in both trials (range across treatment groups in both trials: N1:11–13; N2:55–57; N3:11–14; REM:19–20). In Trial-1 (25mg/50mg/placebo), the change from baseline to M3 in % of TST spent in N1(-0.3±4.7/-0.2±5/0.1±5), N2(2±8/1±7/1±7), N3(-2±6/-2±6/-2±6), and REM(1±6/1±5/1±5) was low and numerically similar across treatments. In Trial-2, the change from baseline to M3 in % of TST spent in each sleep stage was consistent with Trial-1, with no effect of dose. Mean changes from baseline (% of TST) for each sleep stage appeared to be independent from increasing TST. Data for 25mg were consistent between trials.

Conclusion

Daridorexant at any dose, and each more than placebo, increased TST in a dose-dependent manner without affecting the proportion of all sleep stages in patients with insomnia.

Support (if any)

Funded by Idorsia Pharmaceuticals Ltd.

348 Absence of Withdrawal Symptoms and Rebound Insomnia Upon Discontinuation of Daridorexant in Patients with Insomnia

Introduction

Abrupt discontinuation of sleep medications in patients with insomnia often causes withdrawal symptoms and rebound insomnia. In a Phase 3 program evaluating efficacy and safety of daridorexant on sleep and daytime functioning in patients with insomnia during 3 months of treatment, the risks of withdrawal symptoms and rebound insomnia were evaluated at treatment cessation.

Methods

In two randomized, double-blind, 3-month trials, adult (18–64 years) and elderly (≥65) patients with insomnia were assigned (1:1:1) to receive oral daridorexant 25mg, 50mg or placebo (Trial-1, NCT03545191) or 10mg, 25mg or placebo (Trial-2, NCT03575104) every evening. Each trial included a 7-day, single-blind, placebo run-out period following double-blind treatment to evaluate withdrawal symptoms and rebound insomnia. Withdrawal effects were assessed by the change in Benzodiazepine Withdrawal Symptom Questionnaire (BWSQ) total score, from last assessment on double-blind treatment to end of placebo run-out, and occurrence of relevant adverse events (AEs). Rebound insomnia was assessed objectively by change in wake-after-sleep-onset (WASO) and latency-to-persistent sleep (LPS), from baseline to first night of placebo run-out, and by subjective total-sleep-time (sTST), from baseline to end of run-out (mean of 7-days). Analyses included all patients who received ≥1 dose of placebo run-out treatment (Trial-1: N=852; Trial-2: N=851).

Results

No increase in mean BSWQ score from last assessment on double-blind treatment to end of placebo run-out was reported (Trial-1: 25mg, -0.6±2.3; 50mg, -0.6±2.3; placebo, -0.7±2.3; Trial-2: 10mg, -0.5±2.6; 25mg, -0.4±1.9; placebo, -0.4±1.4). No patients had a BWSQ score &gt;20 at end of run-out. No AEs suggestive of withdrawal symptoms were reported. Mean WASO and LPS values (min) decreased from baseline to placebo run-out (WASO Trial-1: 25mg, -8.6±55.5; 50mg, -2.5±52.4; placebo, -20.4±45.8; Trial-2: 10mg, -11.6±58.3; 25mg, -5.1±57.9; placebo, -26.2±53.5; LPS Trial-1: 25mg, -17.2±56.7; 50mg, -15.0±55.8; placebo, -27.8±47.2; Trial-2: 10mg, -17.3±67.2; 25mg, -10.3±67.3; placebo, -18.3±63.8) while sTST values (min) increased (Trial-1: 25mg, 43.3±53.8; 50mg, 42.9±59.6; placebo, 42.3±52.7; Trial-2: 10mg, 43.3±52.9; 25mg, 46.8±55.4; placebo, 42.3±53.8) indicating absence of rebound effects.

Conclusion

Treatment with daridorexant for up to 3-months was not associated with any evidence of drug withdrawal or rebound insomnia upon abrupt discontinuation, indicating no safety concerns for patients should treatment be stopped.

Support (if any)

Funded by Idorsia Pharmaceuticals Ltd.

Development and Validation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ)

Background and Objective

Chronic insomnia has major consequences for daytime functioning, yet no fully validated patient-reported outcome instrument for once-daily assessments is available to measure these consequences. This study describes the development and psychometric evaluation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ).

Methods

The Daytime Insomnia Symptom Scale (DISS), an existing 20-item instrument for assessing daytime functioning, was modified to give an 18-item version of the IDSIQ (IDSIQ-18) based on iterative qualitative interviews with 54 subjects with insomnia and expert input. The construct validity and other psychometric properties of the IDSIQ-18 were analyzed based on an interventional study (NCT03056053) in which subjects with insomnia received zolpidem (5 or 10 mg) daily for 2 weeks and an observational study among subjects with no diagnosis of insomnia (good sleepers). Participants in both studies completed the IDSIQ-18 daily for 2 weeks. Exit interviews were conducted with a sample of subjects who completed the interventional study to elicit concepts defining the experience of insomnia, to assess understanding of the response scales, and to determine meaningful change thresholds. Exploratory factor analysis and Rasch analysis were conducted to further assess the structure and latent model for the scoring of the final IDSIQ instrument. Further psychometric evaluation of the final IDSIQ was then conducted.

Results

Subjects in both the interventional study (N = 114) and observational study (N = 103) were predominantly female (65% for subjects with insomnia and 60% for good sleepers). Mean age was 51 years for subjects with insomnia and 45 years for good sleepers. Subjects in the exit interviews (N = 41) demonstrated a good understanding of the IDSIQ-18 response scales. Day 1 mean scores were higher (worse) in subjects with insomnia compared with good sleepers. Based on inter-item correlation, exploratory factor, and Rasch analyses and review of the qualitative data, four items were removed. This yielded the final IDSIQ, with 14 items comprising three domains: Alert/Cognition, Mood, and Sleepiness. The domain structure was determined in a confirmatory factor analysis. Evidence of internal consistency reliability was strong: day 1 Cronbach’s alpha was 0.917 for IDSIQ total score and 0.806–0.918 for the domains. Test-retest reliability, assessed for subjects with insomnia with no change on the Patient Global Assessment of Disease Severity scale between day 1 and day 8, was also good (intra-class correlation coefficient 0.856–0.911). Meaningful change thresholds derived for this sample using anchor-based approaches were 20 for IDSIQ total score, 9 for the Alert/Cognition domain, 4 for the Mood domain, and 4 for the Sleepiness domain.

Conclusions

These studies, which closely followed Food and Drug Administration Guidance for Industry on patient-reported outcome measures, support use of the IDSIQ as a fit-for-purpose measure for deriving valid and reliable endpoints in insomnia clinical research trials and real-world studies.

Electronic supplementary material

The online version of this article (10.1007/s40271-020-00474-z) contains supplementary material, which is available to authorized users.