FOR IMMEDIATE RELEASE

Toray Industries, Inc. (“Toray”) [TSE: 3402], Japan Tobacco Inc. (“JT”) [TSE: 2914] and Torii Pharmaceutical Co., Ltd. (“Torii”) [TSE: 4551] announced today that the companies have filed for a new drug application in Japan for “TRK-820,” an antipruritic agent originally discovered by Toray.  “TRK-820” has been developed for treatment of severe uremic pruritus in hemodialysis patients based on the agreement signed by the three parties on March 16, 2005, for joint development and marketing.

Hemodialysis-related uremic pruritus is a condition that causes systemic and severe itching, without inflammation, and with an unclear pathology.  Hemodialysis patients with serious pruritus suffer from lack of sleep due to severe itching, which not only worsens their quality of life (QOL), but is also one of the causes of aggravated systemic symptoms.  This itching cannot be fully suppressed by conventional antipruritic agents such as antihistamines, and development of effective drugs has long been awaited.

“TRK-820” is a selective κ(kappa) opioid receptor agonist and is expected to be effective with its novel mechanism in treating itching which is resistant to conventional drugs such as antihistamines.

Notes:

1. Characteristics of TRK-820
TRK-820 is a novel selective κ(kappa) opioid receptor agonist, with a different mechanism from existing antipruritic drugs such as antihistamine.  The drug is thought to suppress the pruritus mediated by the opioid-related mechanism and hence is expected to be effective in treating itching that is resistant to existing treatments such as antihistamine drugs.

2. Opioid receptors
Receptors are the molecules located on the cell membranes. When receptors are bound by the medical compounds, a biological response is triggered.  There are a wide variety of receptors in the human body and each of them has a different specificity to its binding compounds and pharmacological functions expressed by such bindings.  An opiate is one such medical compound that binds to a receptor and expresses a response, and its receptors are known as opioid receptors.  Whereas it was thought that there was only one type of opioid receptor when it was initially discovered, the subsequent evolution of the research in the area revealed that it is largely classified into three receptor types indicated as μ(mu), δ(delta) and κ(kappa).

3. Agonists

<Corporate Profiles>