Daridorexant for patients with chronic insomnia disorder: number needed to treat, number needed to harm, and likelihood to be helped or harmed.

Objectives: Appraise the evidence for daridorexant 50 mg and 25 mg versus placebo when treating chronic insomnia disorder in terms of number needed to treat (NNT), number needed to harm (NNH), and likelihood to be helped or harmed (LHH).

Methods: NNT, NNH, and LHH were calculated from a 3-month pivotal Phase 3 study (N = 930; randomized 1:1:1 to daridorexant 50 mg, daridorexant 25 mg, or placebo once nightly). Wakefulness after sleep onset, latency to persistent sleep, self-reported total sleep time, Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ), and Insomnia Severity Index were used for the NNT efficacy analysis. NNH safety analysis was performed using rates of adverse events (AEs) occurring in >1% of the participants in any arm. LHH was assessed for all NNT estimates, contrasting them with NNH estimates for somnolence, headache, and fatigue AEs.

Results: NNT estimates for daridorexant 50 mg versus placebo were <10 for clinically meaningful thresholds across all outcomes. NNT estimates for daridorexant 25 mg versus placebo were not as robust as those observed for daridorexant 50 mg, with many values exceeding 10. NNH estimates for daridorexant 50 mg and 25 mg versus placebo did not show a statistically significant treatment difference except for falls, where NNH was negative for the daridorexant 50 mg group (-44 [95% CI -328; -21]; rate of falls was greater with placebo than for daridorexant 50 mg). All LHH ratios at Months 1 and 3 were >1 (except for daridorexant 25 mg for the IDSIQ alert/cognition domain), indicating that patients were more likely to respond to daridorexant 50 mg and 25 mg than to experience an AE of somnolence, headache, or fatigue.

Conclusion: Daridorexant 50 mg and 25 mg have a favorable benefit-risk ratio over 3 months. Daridorexant 50 mg demonstrated more robust (lower) NNT estimates versus placebo than daridorexant 25 mg.