Biotech company Actelion is due to report results from clinical trials of two key drugs at the weekend, and positive results could further boost its already highly valued stock, analysts said.

Swiss-based Actelion will report data from several late-stage studies of its top-seller Tracleer for pulmonary arterial hypertension (PAH), as well as mid-stage trial results from experimental sleeping pill ACT-078573.

Actelion is a rare success story among European biotech companies, but it is still heavily dependent on Tracleer and is trying to extend its use to other indications and diversify its portfolio of other drugs.

Data from trials of Tracleer in patients with chronic thromboembolic pulmonary hypertension (CTEPH), a new children's formulation, use in combination with Pfizer Inc.'s Revatio and results in less sick patients are are all due at the European Society of Cardiology Congress in Vienna.

Detailed results from the Phase III trial in less sick patients could be the most important in further boosting the Tracleer franchise, which had sales of 899 million Swiss francs

($751 million) last year, said Landsbanki Kepler analyst Denise Anderson. We expect that strong Phase III data -- we already know the trial was positive -- will encourage physicians to test high-risk patients, which could significantly boost the pool of diagnosed PAH patients, Anderson said in a note.

Upside to Actelion's profitability could be hundreds of millions annually, said Anderson, who has a buy rating on the stock.

Actelion's shares have already gained nearly 21 percent in 2007, after more than doubling in value last year, and now trade at about 22 times forecast 2008 earnings, according to Reuters data -- a discount to Belgian pharmaceutical group UCB but still a premium to the European healthcare sector.


Actelion also has high hopes its insomnia drug ACT-078573 could help diversify its portfolio and will report Phase II data on Sunday at the start of the 2007 World Sleep Congress.

Actelion plans to start pivotal Phase III tests later this year, putting it ahead of GlaxoSmithKline in developing an orexin drug -- novel pills that aim to block receptors for neuropeptides that play a key role in maintaining wakefulness and regulating the sleep-wake cycle.

Most people with insomnia go untreated, so the market potential is probably much larger than current sales. Helvea analyst Olav Zilian estimates peak annual sales of ACT-078573 could surpass 2 billion francs.

That forecast depends on several factors, particularly confirmation there are no side effects like narcolepsy-cataplexy, anorexia and infertility, which may require larger late-stage studies, Zilian said.