Otsuka Pharmaceutical Co., Ltd. announces the granting of approval in Japan for the additional dosage form of Samsca^® granules 1% (tolvaptan), a vasopressin V₂-receptor antagonist.

Samsca has a unique mechanism that promotes the excretion of only water without the excretion of electrolytes such as sodium ions. In Japan, it was approved in October 2010 for the treatment of excess water retention in patients with cardiac failure, and in September 2013 for excess water retention for patients with hepatic cirrhosis. In March 2014, it was approved in Japan as the first treatment in the world to slow the progression of Autosomal Dominant Polycystic Kidney Disease (ADPKD).

Tolvaptan has been approved since 2009 in the US and Europe for the treatment of hyponatremia. Since 2015, it has been approved for the treatment of ADPKD in Europe, Canada, and South Korea. Currently Samsca/JINARC* is approved for different indications in over 40 countries.
_{*Marketed as JINARC for the treatment of ADPKD outside Japan}