Otsuka Pharmaceutical Co., Ltd.

March 28, 2022

Otsuka Obtains Approval in Japan for SAMTASU® for I.V. Infusion,
a V2 -Receptor Antagonist for the Treatment of Cardiac Edema

Otsuka Pharmaceutical Co., Ltd. (Otsuka) announces that it has received regulatory approval in Japan for the manufacture and sale of SAMTASU® 8mg and 16mg Intravenous Infusion for the treatment of cardiac edema.

SAMTASU is a prodrug of oral tolvaptan (generic name is tolvaptan sodium phosphate). A prodrug is a medication that is converted into an active drug in the human body following administration. Tolvaptan, discovered by Otsuka, is a novel compound that is as an antagonist of the vasopressin V2-receptor. It inhibits water reabsorption at the renal collecting duct, thereby enhancing water diuresis (aquaresis) without depletion of electrolytes. Until now, tolvaptan has been available only in oral form.

Outcomes from the phase 3 trial showed non-inferiority of SAMTASU versus tolvaptan 15 mg tablets in the trial primary endpoint, defined as change in body weight from baseline up until administration of the final dose. In addition, the main secondary endpoints also showed improvement comparable to that of tolvaptan in tablet form. No safety issues were identified during the trial.

SAMTASU is an intravenous diuretic that provides a new treatment option for patients with fluid retention who have difficulty receiving tolvaptan orally.