Bristol-Myers Squibb is developing BMS-193884, an oral endothelin antagonist, for the potential treatment of congestive heart failure (CHF) and pulmonary hypertension [206604]. The compound entered phase I trials in November 1996 [242721] and had progressed to phase II trials [399460], [441398]. Structural modifications led to the development of a second-generation analog, BMS-207940, a biphenylsulfonamide endothelin A receptor-selective antagonist, and the probable discontinuation of the first clinical candidate, BMS-193884 [446511]. By April 2002, BMS-207940 was in phase I trials [446511]. By March 2002, filing for NDA was expected to take place in 2004 at the earliest [452734].