&NA;TBC 11251 (IPI 1040), a selective endothelin-A (ET-A) receptor antagonist, has potential for use in the treatment of congestive heart failure. It is undergoing phase I development in the UK. In the US it is undergoing phase IIa development in the IV form and phase I in the oral form with Texas Biotechnology. The phase IIa study was prematurely terminated as statistically significant results were achieved in fewer patients than expected. Asecond phase IIa study in 24 patients, using a higher dose, has been completed and also demonstrated a statistically significant improvement versus placebo.These studies used an IV formulation, but Texas Biotechnology plans to initiate phase II trials using an oral form. TBC 11251 is also at the preclinical stage of development for the treatment of pulmonary hypertension and is expected to be useful in treating diseases such as hypertension, stroke,myocardial infarction, chronic obstructive pulmonary disease and acute renal failure.Texas Biotechnology has entered into an agreement with LG Chem for the development of TBC 11251. LG Chem will market the drug in Asia, excluding Japan.