FDA accepts Merck & Co's suvorexant; panel backs Novo's Tresiba and Ryzodeg

US drug giant Merck & Co (NYSE: MRK) says that the New Drug Application for suvorexant, the company's investigational insomnia drug candidate, has been accepted for standard review by the US Food and Drug Administration. If approved, suvorexant would be the first in a new class of medicines, called orexin receptor antagonists, for use in patients with difficulty falling or staying asleep.

Suvorexant will be evaluated by the Controlled Substance Staff of the FDA during NDA review. If approved by the FDA, suvorexant will become available after a schedule assessment and determination has been completed by the US Drug Enforcement Administration, which routinely occurs after FDA approval. The company is continuing with plans to seek approval for suvorexant in other countries around the world.

Assuming suvorexant gains marketing approval, it would enter a US market sector valued at around $2.7 billion in 2010, but has been dominated by Sanofi’s Ambien (zolpidem), which is now off patent, and Eisai’s Lunesta (eszopiclone), as well as a range of cheaper generic medicines. Assurance of suvorexant's long-term safety is a boon to Merck after "safety observations" preceding the January 2011 discontinuation of Actelion/GlaxoSmithKline's late-stage orexin candidate, almorexant, fueled speculation that the safety concerns may be a class-wide issue, according to a recent Data Monitor report.