Elinzanetant cut night waking early, but not at twelve weeks

Design

Phase 2, randomised, placebo-controlled, 12 weeks

Population

110 postmenopausal women with moderate-to-severe vasomotor symptoms and sleep disturbance

Primary outcome

Polysomnographic wakefulness after sleep onset

Effect

Week 4 −22.5 min (90% CI −35.5 to −9.5); week 12 −0.9 min (−14.0 to 12.1)

NIRVANA, a phase 2 trial, randomised 110 postmenopausal women aged 40–65 with frequent moderate-to-severe hot flushes and polysomnography-confirmed sleep disturbance to elinzanetant 120 mg, a neurokinin-1 and -3 receptor antagonist, or placebo for 12 weeks.

At week 4, wakefulness after sleep onset fell by about 22 minutes more than placebo (90% CI −35.5 to −9.5). By week 12 the difference had disappeared on the same measure (−0.9 minutes, 90% CI −14.0 to 12.1). Post hoc modelling of all sleep studies, sleep diaries and home monitoring favoured elinzanetant across the period.

For a woman whose main complaint is broken sleep from night sweats, this supports the idea that treating vasomotor symptoms helps sleep. It does not show durable benefit on objective sleep on its pre-specified analysis.

• Ask whether night sweats are waking her — sleep complaints in menopause are often vasomotor.
• Treat the hot flushes first; sleep often improves with them.
• Hormone therapy remains first line for most women without contraindications.
• Neurokinin-receptor antagonists are an option where hormones are contraindicated or declined, subject to local availability.
• Screen for sleep apnoea and depression when poor sleep persists despite symptom control.

Why it matters

The early sleep benefit faded on the primary measure, which tempers claims of a sleep drug.

Don't overread it

This was a 110-woman phase 2 study, and the twelve-week benefit came from post hoc analysis.

The statistics, in plain English

This trial reported 90% rather than 95% confidence intervals, which are narrower and suit an exploratory phase 2 study. The week 12 interval runs from −14 to +12 minutes, centred on zero — no difference. The favourable 12-week picture came from a post hoc model, which is weaker evidence than the planned comparison.

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