A US FDA advisory committee backed the efficacy of Merck & Co’s much-anticipated new insomnia treatment suvorexant at a meeting yesterday, but had reservations about its safety at higher doses.
The panel voted by 13 to 3, with one abstention, that suvorexant was effective and safe at 15mg and 20mg doses. However, voting was split on the safety of higher doses, with a slim majority (8 to 7, with 2 abstentions) concluding that the drug is not acceptably safe at 30mg and 40mg.
Merck is seeking approval for starting doses of 15mg or 20mg – depending on the age of the person taking it – with an option to increase the dose to 30mg to 40mg if the lower doses are not effective.
Meanwhile, the FDA panel also concluded that a 10mg was also effective based on the result of a phase II study, and said Merck should not have to carry out additional studies to support approval of the lower dose.
If approved by the FDA, suvorexant would be the first in a new class of insomnia medicines called orexin receptor antagonists, which block a hormone linked to wakefulness. Merck believes the drug can help people sleep without the side effects of current therapies such as next-day drowsiness and dependency.
Documents published by the FDA ahead of the panel meeting suggest the agency is not so sure about next-day effects on operations such as driving, however, and also has questions about other side effects, such as suicidal thoughts.
The panel vote and discussion “bring us one step closer to providing physicians with another option to help patients struggling with insomnia,” said Merck’s head of neuroscience and ophthalmology Darryle Schoepp.
“We look forward to working with the FDA as the agency continues its review of our application,” he added. The agency is scheduled to deliver its verdict on the drug in the summer.
Even if it does get the go-ahead from the agency, Merck will have to wait for a scheduling decision from the US Drug Enforcement Administration (DEA) before it can put the product on sale. That decision can take some time, as Arena Pharmaceuticals found when it awaited a ruling in its obesity drug Belviq (lorcaserin).
The drug is one of a clutch of new compounds in late-stage development at Merck that the company is hoping will drive growth in the next decade, alongside vorapaxar for acute coronary syndrome, human papillomavirus (HPV) vaccine V503 and odanacatib for osteoporosis, although the latter has been delayed after a safety signal was seen in trials that requires further investigation.
The company suffered another R&D setback recently when it dropped development of another phase III project – cardiovascular treatment Tredaptive ER (laropiprant and niacin) – after disappointing results in the HPS-2 THRIVE trial.
Of the late-stage products suvorexant is widely regarded as having the greatest potential, at least in the near-term, with annual sales expected to top $500m within three years and to reach $1bn-plus at peak.