OPC-131066

OPC-131066 is an investigational small molecule diuretic developed by Otsuka Pharmaceutical. It functions as a vasopressin V2 receptor antagonist, a class of drugs known as aquaretics that promote the renal excretion of solute-free water by blocking the action of arginine vasopressin in the collecting ducts. This mechanism is intended to treat conditions associated with water retention or electrolyte imbalances, such as hyponatremia and heart failure. OPC-131066 was evaluated in a first-in-human Phase 1 clinical trial (jRCT2080224712) to assess its safety, tolerability, pharmacokinetics, and pharmacodynamics in healthy adult males, including the effect of food on its absorption. However, the study was terminated by the sponsor before full completion, and the compound's current development status for specific therapeutic indications remains undisclosed.