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Otsuka product development storiesSamsca / JINARC Product story

Developing the world's first therapeutic drug to tackle intractable ADPKD

A drug with a novel therapy, inspired by a comment from a doctor, and resulting in a new treatment category

Triggered by a doctor's request

Conventional diuretics, used in cases such as when a patient has edema (swelling due to excess fluid), lead to the excretion of electrolytes together with water. The issue triggered a request from a physician: "I want a diuretic that only excretes water."
This request sparked our research into vasopressin (an anti-diuretic hormone) and our discovery of the V2-receptor antagonist. A 26-year-journey resulted in the new drug tolvaptan that promotes the excretion of only water. The product was first launched in the U.S. in 2009 and now is available in many countries. For example, in Japan, it is used to treat excess water retention in patients with heart failure or with hepatic cirrhosis.

A second breakthrough

Otsuka’s leadership recognized that tolvaptan’s unique mechanism suggested significant potential in other treatment areas.
A researcher at an American university published in an academic journal that Otsuka’s vasopressin V2-receptor antagonist inhibited progression of autosomal dominant polycystic kidney disease (ADPKD) in mice. As a rare disease for which there was no known treatment, polycystic kidney disease later was categorized as a Designated Intractable Disease by the Japanese government. When top management heard about the research findings, they made a snap decision to develop an ADPKD treatment.
In addition to a lack of any treatment for ADPKD, the death of a company employee from this disease galvanized the leadership to act. With this decision, we took on two difficult challenges at the same time, launching the drug for one indication while developing it for another.

Collaborative clinical study in 15 countries

No full-scale clinical studies had ever been conducted on ADPKD before, and no primary clinical indicators had been established. Nevertheless, we conducted a clinical trial on over 1,400 patients in 15 countries with the cooperation of physicians and patients around the world, in order to develop a treatment as quickly as possible for patients waiting anxiously. In 2014, the world’s first-ever treatment that slows progression of ADPKD was approved in Japan with the brand name Samsca. It is now sold in multiple countries outside Japan under the name JINARC except in the U.S., where it has been marketed with the brand name JYNARQUE following the May 2018 launch there.
The initial development of Samsca was triggered by the chance comment of a doctor, but it eventually became a drug with two very different applications. Today, the drug is used by patients in 30 countries and regions.

Samsca / JINARC

Samsca is an Otsuka-discovered aquaretic with a novel mechanism of action that promotes excretion from the body of water only without affecting the excretion of electrolytes. It does this by inhibiting the antidiuretic hormone vasopressin. In Japan, it was approved for edema from heart failure (accumulation of fluid) in 2010 and edema for cirrhotic patients in 2013. In 2014 Samsca was approved in Japan as the first-in-the-world treatment of autosomal dominant polycystic kidney disease (ADPKD), and additional approvals have been received in geographies including North America and the EU member states. Currently, Samsca / JINARC is approved for several indications in approximately 30 countries and regions.

What is ADPKD? (Autosomal Dominant Polycystic Kidney Disease)

ADPKD is a genetic disease in which numerous cysts (fluid-filled sacs) develop in both kidneys, enlarging them and impairing their function. As the disease progresses, nearly half of patients ultimately develop end-stage kidney disease and require dialysis or kidney transplantation. ADPKD is considered to be a rare disease, but it has a high incidence rate among genetic diseases. There are approximately 30,000 diagnosed patients in Japan, 200,000 in Europe, and 140,000 in the U.S.