New Sleeping Pill on Horizon

Suvorexant sleeping pill by Merck headed to FDA following successful clinical trials

(RxWiki News) What if you could take a sleeping pill that, instead of making you sleepy, simply attacked the chemicals in the brain that were keeping you up? Such a drug may be on the way.

Today, Merck released information at a sleep conference regarding a Phase III trial on a new drug called suvorexant, which helped patients fall asleep faster and stay asleep longer than a placebo did.

"Ask your doctor for help if you struggle with insomnia."

Chemical messengers called orexins hang out in the hypothalamus, the part of the brain that controls sleep, and help people stay awake. Blocking these orexins can help people fall asleep and stay asleep - which is exactly what suvorexant purports to do.

"This investigational drug targets insomnia in a way that is different from other medicines," said Andrew D. Krystal, MD, a professor of Psychiatry and Behavioral Sciences at Duke University Medical Center. "The potential for a new and different option would be welcomed by patients with insomnia who cannot sleep through the night."

Another drug that works on the hypothalamus, altering the body's circadian rhythms, is ramelteon (Rozerem). Suvorexant, if approved by the US Food and Drug Administration, would be part of a new class of drugs called orexin receptor antagonists.

Common sleep medications like Ambien and Lunesta are in a class of drugs called selective Gamma-aminobutyric acid (GABA) medications, which target the brain's GABA receptors, which affects people's levels of alertness or relaxation.

The data presented by Merck included information on two Phase III trials on the effectiveness of suvorexant.

In both trials, participants were given either a high dose of suvorexant (40mg for patients aged 18 to 64 and 30mg for patients 65 and older), a low dose of suvorexant (20mg for ages 18-64 and 15mg for patients 65 and older) or a placebo for three months.

Trial 1 involved 1,021 patients, with 383 getting a high dose and 384 getting the placebo.  

Trial 2 involved 1,009 patients, with 387 receiving the high dose and 383 receiving a placebo.

The researchers conducting the trials conducted sleep lab studies to see how quickly patients fell asleep and stayed asleep, and the patients were surveyed as well.

After three months of Trial 1, patients taking suvorexant reported falling asleep 26 minutes faster compared to the 17 minutes faster reported by those taking the placebo. The patients taking suvorexant also believed they stayed asleep an hour longer when contrasted to their sleep before the trial, compared to 40 minutes longer for those taking the placebo.

The actual numbers observed in the sleep study were a little different but still showed positive results for suvorexant. Those taking suvorexant fell asleep 36 minutes faster than they used to and stayed asleep an extra 48 minutes. Those taking placebo fell asleep 27 minutes faster than they did pre-trial and stayed asleep 25 minutes longer.

Trial 2 showed similar results, except that the sleep studies did not show suvorexant takers falling asleep substantially faster than those on placebo.

Across the three months, 25 percent of those taking suvorexant reported side effects, compared with 14 percent of those taking placebo who reported side effects.

The most common side effects - reported by more than five percent of the trial participants - included sleepiness and headache.

When the researchers compared the suvorexant group to the placebo group in terms of memory, attention, visual scanning and motor speed the morning after sleeping, there were no substantial differences in the patients' scores.

Merck announced plans to file a New Drug Application for suvorexant with the US Food and Drug Administration (FDA) this year.

Merck's data was presented June 13 at SLEEP 2012, the 26th Annual Meeting of the Associated Professional Sleep Societies.

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Review Date: 
June 13, 2012