March 24, 2006

FDA says Encysive lung drug

WASHINGTON (Reuters) - Encysive Pharmaceuticals Inc.'s drug Thelin is "approvable" for treating a rare, often-fatal lung condition, a U.S. Food and Drug Administration (FDA) spokeswoman said on Friday.

The FDA sent an "approvable letter" to the company saying Thelin could be approved if certain conditions were met, FDA spokeswoman Susan Cruzan said. She did not disclose the conditions.

The Houston-based company is seeking permission to sell Thelin for treating pulmonary arterial hypertension (PAH), which causes severe shortness of breath and often kills.

The failure to win full approval for Thelin will likely be viewed as positive for Swiss biotechnology company Actelion, which relies heavily on its PAH treatment Tracleer to sustain growth.

"Any delay would provide an upside to our Tracleer forecasts," Kepler Equities analyst Denise Anderson said in a note to clients.

While Tracleer once had the PAH market pretty much to itself, it is now facing increased competition from Pfizer Inc.'s Revatio, which contains the same active ingredient as Viagra.

Thelin would be another direct competitor for treating the rare condition that often leads to the need for a heart and lung transplant.

A fourth drug for PAH called ambrisentan is being developed by Myogen Inc..