Icos teams with Texas biotech for drug trials

Bothell-based Icos has teamed up with Texas Biotechnology to develop a new class of disease-fighting compounds called en dothelin antagonists.

The venture adds a third experimental drug to Icos' roster of products in the later stages of development.

The first major projects with Houston-based Texas Biotechnology will be to start a late-stage Phase IIb/III clinical trial using one of the antagonists, sitaxsentan, in patients who have pulmonary hypertension; continue experiments with that drug in chronic-heart-failure patients; and explore other uses for other similar compounds.

Investors responded enthusiastically to the deal, sending Icos stock up $1.813, or 4.6 percent, to $41.50 yesterday.

Icos will make payments totaling as much as $55.5 million to Texas Biotechnology when key hurdles in the development and commercialization of the new drugs have been overcome.

The compounds are called antagonists because they block the endothelin-A receptor, a substance produced by the body that contributes to high blood pressure.

In early tests, the antagonists have halted and reversed the chain of events leading up to increased pressure in the artery that connects the right side of the heart to the lungs.

Icos' other two late-stage drugs are IC351, for impotence, and Pafase, which blocks severe inflammation after an infection or trauma.

Tyrone Beason's phone message number is 206-464-2251. His e-mail address is: tbeason@seattletimes.com