Merck Insomnia Drug Safe Only in Lower Doses, Panel Says

Merck & Co. (MRK)’s experimental insomnia drug, meant to be a less disruptive alternative to Sanofi’s Ambien sleeping pill, is safe only at lower doses, U.S. regulatory advisers said.

Merck is seeking Food and Drug Administration approval to sell the treatment, suvorexant, in two dose ranges. The lowest doses of 15 milligrams to 20 milligrams are safe, a panel of advisers to the FDA voted 13-3 yesterday at a meeting in Silver Spring, Maryland. The highest doses of 30 milligrams to 40 milligrams aren’t safe, the panel said in an 8-7 vote.

The treatment is designed to turn off wakefulness rather than subdue the brain into slumber like branded and generic versions of Ambien and Dainippon Sumitomo Pharma (4506) Co.’s Lunesta, the most widely used insomnia medications. FDA staff said earlier this week they were concerned about severe residual daytime side effects of Merck’s drug that could lead to driving while impaired and suicidal thoughts, especially at high doses.

“There is no evidence the higher doses are more effective but there is more evidence they’re more dangerous,” Jason Todd, a panel member and neurologist at NorthEast Neurology in Concord, North Carolina, said during the meeting.

The advisory panel still determined that the drug does work at all the doses proposed. The panel voted 12-4 that suvorexant helps people fall asleep and 16-0 it helps people stay asleep.

Merck rose 1.3 percent to $47.33 at 4 p.m. New York time.

Lower Dose

The FDA, which doesn’t have to follow the panel’s determinations, is expected to make a decision on whether to approve the drug by the middle of the year, Pamela Eisele, a spokeswoman for Whitehouse Station, New Jersey-based Merck, said prior to the meeting. Suvorexant may generate sales of $526 million in 2017 if approved, based on the average of six analysts’ estimates compiled by Bloomberg.

“We are excited about the potential of suvorexant as a new and different approach to treating insomnia, a serious condition that affects up to one-third of the adult population,” Darryle Schoepp, Merck’s head of neuroscience and ophthalmology drug research, said in an e-mail. The “votes and discussion bring us one step closer to providing physicians with another option to help patients struggling with insomnia.”

The panel decided against recommending study on a 10 milligram dose that Merck hadn’t proposed. Advisers said results from an earlier, smaller trial were enough to convince them suvorexant is effective at that lower dose.

Drowsy Drivers

Merck had argued patients didn’t derive a benefit from the 10 milligram dose. The FDA could approve the 10 milligram dose based on the data from the second of what are typically three phases of trials, Russell Katz, director of the Division of Neurology Products at the FDA, said during the meeting.

“If it’s an adequate and well-controlled trial, that’s OK for us,” Katz said.

The Merck drug causes about the same drowsiness as other approved insomnia drugs. About 20 percent of patients younger than 65 taking the 20 milligram dose were impaired after the first night of suvorexant use and about 30 percent were impaired on the 40 milligram dose after the first night. Patients can’t be trusted to recognize their own impairment and not drive, FDA staff said.

The FDA this year said it required Sanofi (SAN) and other makers of insomnia pills containing the ingredient zolpidem to cut by half the recommended doses for women after the agency found lingering effects of the drug in the morning.

If the FDA approves Merck’s drug, the company would still need to wait on the Drug Enforcement Administration to make a designation on restrictions for distribution based on the potential for abuse. That process could take four months or longer, Sable said. Insomnia drugs have historically been considered a Schedule IV medication, the second least restrictive of the DEA’s five classifications.

To contact the reporter on this story: Anna Edney in Washington at aedney@bloomberg.net

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net

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