Actelion says trial drug significantly improves sleep

ZURICH (Reuters) - Swiss biotech firm Actelion's experimental sleep drug, the first of a new class of potential medicines, significantly improved sleep for insomniacs in mid-stage clinical trials, the company said on Sunday.

In data presented at the World Sleep Congress in Cairns, Australia, Actelion's almorexant drug, one of a new class of potential sleep drugs called orexin receptor antagonists, was shown to restore sleep when tested on 147 insomniacs.

"The results of this study prove that almorexant significantly improves the primary parameter of sleep efficiency," Actelion said. The parameter was time spent asleep in bed during an eight-hour period.

The drug will move to Phase III or late-stage clinical testing by the end of the year, it said, putting it ahead of GalxoSmithKline to develop an orexin drug. Mid-stage clinical trial data had been eagerly awaited by analysts.

Actelion is currently heavily dependent on Tracleer, a drug that treats a rare form of hypertension. Signs that it has a potential new blockbuster medicine on its hands could lift the company's shares, analysts have said.

Generic competition to top-selling Ambien is currently eroding the multi-billion dollar market for sleeping pills, but drug companies are pinning their hopes on new, and hopefully more effective, alternatives like orexin antagonists.

These experimental pills are designed to block receptors for neuropeptides that play a key role in maintaining wakefulness and regulating the sleep-wake cycle.

In addition to the time spent asleep, Actelion said the data showed there were clinically relevant improvements in two further parameters and an increase or maintenance of the percentage of time spent in REM (Rapid Eye Movement) sleep.

Unlike traditional sleep medicines, Actelion said treatment with the drug was not associated with any relevant negative effects on performance the next day.

"These findings confirm the pivotal role of the highly specific orexin system in controlling the sleep-wake cycle," said Actelion's head of clinical pharmacology, Jasper Dingemanse.

"These data indicate that almorexant assists patients in falling and staying asleep in a non-sedative fashion, while at the same time not exhibiting any negative effects on next-day performance," he added.

Sanofi-Aventis, which has long dominated the insomnia market with Ambien, also has a new drug in development called eplivanserin -- a 5HT2 antagonist -- which is already in Phase III development.

Analysts think the new treatments from Actelion and Sanofi-Aventis could double the size of the U.S. market for insomnia drugs to $5-$7 billion a year and possibly as much as $8-$12 billion.