&NA;Ecadotril [sinorphan, (S)-acetorphan] is a neutral endopeptidase inhibitor currently undergoing phase III clinical trials for hypertension and heart failure with Bioprojet in France. Shionogi has licensed ecadotril from Bioprojet, and is conducting phase II trials of the agent for heart failure in Japan. The agent has been exclusively licensed to Bayer AG worldwide except for France and Japan. Bayer is conducting phase II clinical studies with ecadotril in Germany and the US. Ecadotril is the (S)-enantiomer of acetorphan, and is 2 to 3 times more potent than the (R)-enantiomer retorphan.