By Karen Young

Myogen Inc. has agreed with Abbott Laboratories Inc. to assume exclusive worldwide rights to develop and take to market the endothelin receptor antagonist BSF 208075, or ambrisentan.

The deal stems from a co-development agreement between Denver-based Myogen and Knoll AG, of Ludwigshafen, Germany, forged in December 2000 to have Myogen study the Knoll compound in exchange for future royalties. Three months after the agreement was finalized, Knoll was acquired by Abbott, of Abbott Park, Ill.

¿At that point, Abbott found themselves with a broader portfolio with a lot of compounds,¿ said William Freytag, president and CEO of Myogen. ¿They did a portfolio review, and decided they would allow themselves to be licensed out 100 percent, rather than keep some of it themselves.¿

The deal requires Myogen to provide undisclosed up-front money and milestone payments later, as well as royalties. Freytag said the ¿economic terms of this deal and the royalty structure are fairly standard.¿

Endothelin receptor antagonists have been shown to prevent the constriction of blood vessels and increase blood flow to vital organs. Ambrisentan is selective for one of two endothelin receptors ¿ Type A, which is thought to play a role in disease processes.

Knoll conducted a Phase I safety study in Europe on ambrisentan, and Myogen plans to begin Phase II studies for chronic renal failure and pulmonary artery hypertension in the next several months, after filing an investigational new drug application. There will likely also be sites in Europe as part of the study, since Knoll already filed for regulatory approval there. Myogen said chronic kidney failure affects 10 million patients in the United States and is one of the primary complications of diabetes and hypertension.

A study in chronic heart failure also is planned, Freytag said. Health care costs associated with this condition exceed $30 billion annually, the company said.

¿The key to this program is that today¿s therapies do not affect disease progression in any effective way,¿ he said. ¿We¿re seeking to find therapies that truly affect the progression of disease. That is obviously a longer-term strategy.¿

In the shorter term, the company¿s strategy is to in-license compounds already in clinical development, Freytag said.

Myogen has a second compound, enoximone, a positive inotropic agent that increases the force of contraction of the heart. It already is on the market in Europe as Perfan, the intravenous form of enoximone. A Phase III trial for the oral formulation is under way in the United States and Europe for the oral formulation. This three-year program will continue into 2004, Freytag said.

Privately held Myogen was formed in 1996, and has about 40 employees. In August, the firm completed one of the largest rounds by a private company up to that time this year in August when it raised $52 million in its Series D round. Most of that money is to be dedicated to the company¿s Phase III program in heart failure. (See BioWorld Today, Aug. 28, 2001.)