Suvorexant switches off wakefulness to help patients drop off quicker and stay asleep longer

There’s good news on the way for insomniacs, according to US pharma major Merck & Co. In Phase III trials, insomnia drug candidate suvorexant performed well, reducing the time patients needed to fall asleep and increasing the total time sleeping, with som patients benefitting from the very first night of treatment.

Suvorexant blocks orexin, a neurotransmitter that is important in sleep regulation and produced primarily in the hypothalamus region of the brain. It is described as an attempt to tackle insomnia from a new direction by switching off wakefulness rather than inducing sleepiness. Merck will file for marketing approval in the US later this year and, if approved, suvorexant would then represent the first drug in a new class.

The drug was studied in two doses. Patients on the 40mg dose fell asleep, on average, 26 minutes sooner and slept 60 minutes longer than they did before treatment. This compared with 17 minutes sooner and 41 minutes longer for patients treated with placebo. The changes for how quickly patients transitioned to continuous sleep and total time spent awake during the night were also positive. The company saw similar results with the 30mg dose.

Suvorexant was developed in house at Merck by a team led by Chris Cox at the R&D centre in West Point, Pennsylvania. But much of the proof of principle work in this area was arguably done by Swiss firm Actelion, which, with the help of GlaxoSmithKline, took almorexant – another orexin antagonist – through to Phase III before abandoning it in January 2011 because of side effects.