Alexion Pharmaceuticals Inc posted a narrower third-quarter loss, helped by sales of its key drug Soliris, sending its shares up nearly 8 percent in early electronic trade.

It looks like the fundamentals here were driven by very good U.S. demands and also a positive influence from pre-commercial European launch. So overall, everything looks very, very solid, Cowen & Co analyst Rachel McMinn said by phone.

Alexion currently sells Soliris in the United States, and is planning to launch it in two European countries -- Germany and the United Kingdom -- by the end of this year. The company said U.S. sales of Soliris began from the second quarter of 2007.

Soliris was approved in March by U.S. regulators to treat paroxysmal nocturnal hemoglobinuria, or PNH, a rare, life-threatening genetic blood disorder in which red blood cells develop abnormally and can lead to anemia, fatigue, pain and difficulty breathing.

Soliris net product sales rose sequentially to $21.8 million from $9.8 million in the previous quarter, beating McMinn's earlier estimate of $18.1 million.

The number of patients on Soliris therapy and the number of treating physicians increased significantly during the third quarter, Alexion said in a statement.

The Chesire, Connecticut-based company posted a net loss of $20.1 million, or 55 cents a share, compared with a net loss of $31.9 million, or $1.02 per share, a year ago.

Total revenue for the period was $22.1 million for the period.

Analysts on average had expected a loss of 73 cents a share, before items, on revenue of $16 million, according to Reuters Estimates.

The company narrowed the range of its 2007 total operating expenses forecast to $160 million to $170 million, from its prior was $160 million to $180 million.

Excluding the expense of employee stock options and other share-based compensation expense, it expects operating expenses of $140 million to $150 million.

Shares of the company, which have soared more than 70 percent this year, were trading at $75.39 in early electronic trade, after closing at $69.95 Wednesday on the Nasdaq. (Reporting by Varsha Tickoo and Jennifer Robin Raj in Bangalore)