Results of a sub-analysis from a Phase III clinical trial of Japanese group Takeda’s Rozerem (ramelteon) show that the agent significantly cut the time it took adults with chronic insomnia to fall asleep.

In the placebo-controlled analysis, around two-thirds of 138 patients who received 8mg of Rozerem experienced at least a 50% reduction in the time it took them to fall asleep. Moreover, no evidence of rebound insomnia - the worsening of symptoms after a person stops taking their medications - or withdrawal effects were found by the study, results from which were presented at the 2006 Annual Meeting of the American Academy of Neurology.

"These data show that Rozerem can be effective in helping patients fall asleep faster without rebound insomnia and other withdrawal effects," commented Thomas Roth, Director of the Sleep Disorders and Research Center in Detroit, Michigan. "This may represent another option for patients who are looking for a sleeping medication that is right for them," he added.

According to the firm, the product, which was approved in the USA in July last year for long-term use in adults, represents the first prescription insomnia medication with a novel therapeutic mechanism of action in 35 years. Its unique action selectively targets two receptors located in the brain's suprachiasmatic nucleus, an area referred to as the body's "master clock" as it regulates 24-hour rhythms such as the sleep-wake cycle.

In what represents an important advantage over existing therapies, clinical evaluation to date indicates that Rozerem is the first and only prescription sleep drug with no evidence of abuse and dependence in clinical studies. Consequently, the agent has not been designated as a controlled substance by the US Drug Enforcement Administration, as is the case with all other prescription drugs for insomnia, including Sanofi-Aventis and Sepracor's rival offerings Ambien (zolpidem) and Lunesta (eszopiclone).

Insomnia, which is defined as difficulty initiating and/or maintaining sleep with accompanying daytime disability, affects more than 130 million people in the world's seven major pharmaceutical markets. However, the market remains largely untapped as only a small proportion of insomniacs currently seek professional help for their condition. Still, the market for sleep drugs is expected to exceed $5.6 billion in 2013, and analysts are forecasting Rozerem's sales could top $898 million a year, according to a Reuters report.