shares slid after the company said its proposed treatment for a chronic lung disease did not improve lung function in recent trials.
In phase II trials, 258 patients received three doses of the drug IC485 to study its effectiveness. IC485 is part of a family of drugs that target the enzyme PDE4, which causes inflammation in chronic obstructive pulmonary disease.
"While we are disappointed with the IC485 study results, we continue to believe that PDE4 inhibitors may prove beneficial in the treatment of inflammatory disorders," said David Goodkin, the company's chief medical officer, in a statement late Wednesday. He said Icos will now shift its focus to developing more potent PDE4 inhibitors.
The Bothell, Wash.-based company, in partnership with
, makes the male impotency drug Cialis, which works by targeting the enzyme PDE5, allowing for increased blood flow.
Icos shares fell 55 cents, or 2.4%, to $22.32. Trading volume -- at more than 500,000 shares -- was already near the daily average of 627,000.