A Phase II Dose-Ranging Study Evaluating the Efficacy and Safety of the Orexin Receptor Antagonist Filorexant (MK-6096) in Patients with Primary Insomnia

BACKGROUND: Filorexant (MK-6096) is an orexin receptor antagonist; here, we evaluate the efficacy of filorexant in the treatment of insomnia in adults. METHODS: A double-blind, placebo-controlled, randomized, two 4-week-period, adaptive crossover polysomnography study was conducted at 51 sites worldwide. Patients (18 toyears) with insomnia received 1 of 4 doses of oral filorexant (2.5, 5, 10, 20mg) once daily at bedtime during one period and matching placebo in the other period in 1 of 8 possible treatment sequences. Polysomnography was performed on night 1 and end of week 4 of each period. The primary endpoint was sleep efficiency at night 1 and end of week 4. Secondary endpoints included wakefulness after persistent sleep onset and latency to onset of persistent sleep. RESULTS: A total of 324 patients received study treatment, 315 received ≥1 dose of placebo, and 318 ≥1 dose of filorexant (2.5mg, n=79; 5mg, n=78; 10mg, n=80; 20mg, n=81). All filorexant doses (2.5/5/10/20mg) were significantly superior to placebo in improving sleep among patients with insomnia as measured by sleep efficiency and wakefulness after persistent sleep onset on night 1 and end of week 4. The 2 higher filorexant doses (10/20mg) were also significantly more effective than placebo in improving sleep onset as measured by latency to onset of persistent sleep at night 1 and end of week 4. Filorexant was generally well tolerated. CONCLUSIONS: Orexin receptor antagonism by filorexant significantly improved sleep efficiency in nonelderly patients with insomnia. Dose-related improvements in sleep onset and maintenance outcomes were also observed with filorexant

Clinical Profile of Suvorexant for the Treatment of Insomnia over 3 Months in Women and Men: Subgroup Analysis of Pooled Phase-3 Data

Rationale: Sex-related differences in the clinical profiles of some insomnia medications have been previously reported. Objective: To evaluate the clinical profile of suvorexant, a novel orexin receptor antagonist approved for treating insomnia at doses up to 20 mg, by sex subgroups. Methods: Efficacy analyses by sex were based on pooled data from two similar phase 3, randomized, double-blind, placebo-controlled, 3-month trials in elderly (≥65 years) and non-elderly (18–64 years) insomnia patients. Two age-adjusted (non-elderly/elderly) dose regimes of 40/30 and 20/15 mg were evaluated, with fewer patients assigned to 20/15 mg. Efficacy was assessed by patient-reported outcomes (N = 1264 women, 707 men) and by polysomnography endpoints in ~75% of patients. Safety analyses by sex (N = 1744 women, 1065 men) included pooled data from the two 3-month trials plus 3-month data from a safety trial of 40/30 mg. Results: The sex subgroup efficacy analyses mirrored the improvements seen for suvorexant 40/30 and 20/15 mg over placebo on patient-reported outcomes and polysomnography sleep maintenance and onset endpoints in the primary analyses; 95% CIs excluded zero in favor of suvorexant for most endpoints in both sexes, and similar efficacy was observed between sexes (95% CIs overlapped). Suvorexant was well-tolerated in women and men, although women in all treatment groups (including placebo) reported more adverse events than men. The most frequent adverse event was somnolence (women: 11.1% for 40/30 mg, 8.5% for 20/15 mg, 2.3% for placebo; men: 10.1% for 40/30 mg, 3.4% for 20/15 mg, 4.2% for placebo). Conclusion: Suvorexant was generally effective and well-tolerated in both women and men with insomnia. ClinicalTrials.gov trial registration numbers: NCT01097616, NCT01097629, NCT01021813

Suvorexant in Elderly Patients with Insomnia: Pooled Analyses of Data from Phase III Randomized Controlled Clinical Trials

OBJECTIVE: Suvorexant is an orexin receptor antagonist approved for treating insomnia at doses of 10-20 mg. Previously reported phase III results showed that suvorexant was effective and well-tolerated in a combined-age population (elderly and nonelderly adults). The present analysis evaluated the clinical profile of suvorexant specifically in the elderly. METHODS: Prespecified subgroup analyses of pooled 3-month data from two (efficacy) and three (safety) randomized, double-blind, placebo-controlled, parallel-group trials. In each trial, elderly (≥65 years) patients with insomnia were randomized to suvorexant 30 mg, suvorexant 15 mg, and placebo. By design, fewer patients were randomized to 15 mg. Patient-reported and polysomnographic (subset of patients) sleep maintenance and onset endpoints were measured. RESULTS: Suvorexant 30 mg (N = 319) was effective compared with placebo (N = 318) on patient-reported and polysomnographic sleep maintenance, and onset endpoints at Night 1 (polysomnographic endpoints)/Week 1 (patient-reported endpoints), Month 1, and Month 3. Suvorexant 15 mg (N = 202 treated) was also effective across these measures, although the onset effect was less evident at later time points. The percentages of patients discontinuing because of adverse events over 3 months were 6.4% for 30 mg (N = 627 treated), 3.5% for 15 mg (N = 202 treated), and 5.5% for placebo (N = 469 treated). Somnolence was the most common adverse event (8.8% for 30 mg, 5.4% for 15 mg, 3.2% for placebo). CONCLUSION: Suvorexant generally improved sleep maintenance and onset over 3 months of nightly treatment and was well-tolerated in elderly patients with insomnia (clinicaltrials.gov; NCT01097616, NCT01097629, NCT01021813)