Merck Fails to Win U.S. Approval for Higher Doses of Drug

Merck & Co., the second-largest U.S. drugmaker, failed to win approval for two higher doses of an experimental therapy for insomnia.

The Food and Drug Administration said safety data didn’t support approval of the sleeping pill known as suvorexant in doses of 30 milligrams and 40 milligrams, Whitehouse Station, New Jersey-based Merck said today in a statement. A dosage of 10 milligrams may be approved once available, Merck said.

“It’s very good news that no additional clinical studies are required,” Roger Perlmutter, who became Merck’s new head of research and development in April, said in a telephone interview. “There’s a clear path to approval.”

The sleeping pill may generate $516 million in sales in 2017, according to the average of seven analysts’ estimates compiled by Bloomberg before today’s announcement. The treatment is designed to turn off wakefulness rather than subdue the brain into slumber like branded and generic versions of Sanofi’s Ambien and Dainippon Sumitomo Pharma Co.’s Lunesta.

It’s not known how long an approval will take, Perlmutter said.

Rejecting the two higher doses will hurt the sales potential of the drug, said Timothy Anderson, an analyst with Sanford C. Bernstein & Co.

Needs Replacements

“Forcing Merck to go with lower doses, and simultaneously turning down the two higher doses because of safety issues, leaves suvorexant with even more mixed commercial prospects,” Anderson said in a note to clients today. It “will make suvorexant a tougher sell in a market where there is plenty of choice and generic availability already.”

Merck needs to make up for sales losses from its asthma medication Singulair, the company’s one-time best-selling treatment that began facing generic competition last year. Merck announced in March that it would replace its head of research with Perlmutter after several setbacks with drugs in testing and cut its profit forecast in May in anticipation of lower sales.

Merck fell less than 1 percent to $46.32 at 4 p.m. New York time. The stock has gained 11 percent in the past 12 months.

While the company is pursuing therapies in Alzheimer’s and cancer, Perlmutter said Merck is still interested in drugs that would be used mostly by primary care physicians.

Breakthrough Therapy

“It is hard to argue with a breakthrough therapy that addresses an important medical problem using a novel mechanism that’s the first in its class to do so,” Perlmutter said. “We need to be opportunistic in taking advantage of the research that we do.”

According to the letter from the FDA, the agency could approve the 10-milligram dose and then allow patients to increase it if it wasn’t effective. Much of the data about the efficacy of that dose was from sleep lab studies, Perlmutter said. Merck also conducted studies where patients reported how well they were sleeping.

“It’s nice to measure data in the sleep lab, but fundamentally people who are sleeping need to feel like they are sleeping better,” Perlmutter said. “The agency’s approach is let’s go with the objective data, and as long as the drug is tolerated well, then if patients feel like they can take more, then they can increase the dose.”

Impaired Driving

A panel of advisers to the agency raised concern that higher doses of the drug may carry too great a risk of next-day driving while impaired and suicidal thoughts.

People with insomnia have trouble falling asleep and staying asleep.

The FDA this year required Sanofi 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.

“They’re interested in erring on the side of lower doses,” Perlmutter said. “The attitude of the FDA is that a new mechanism of action may be associated with new safety concerns once it gets out in the market and a lot of people are taking it.”

If the drug is approved, Merck will still have to wait for the Drug Enforcement Administration to make a designation on the level of restrictions the drug will face on distribution based on its potential for abuse. Insomnia drugs have historically been considered a Schedule IV medication, the second least restrictive of the DEA’s five classifications.

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