Kyowa Hakko Kirin Co, Ltd, announced that Kyowa has decided to continue the domestic development of its proprietary anti-Parkinson's disease drug KW-6002 (generic name: Istradefylline) and move it forward with a phase-3 clinical trial in Japan.

KW-6002 has a novel mechanism of action that specifically antagonizes the adenosine A2A receptor. Kyowa Hakko Kirin initiated the clinical evaluation of KW-6002 in 1996, and conducted phase-2 and 3 studies in the US and Europe to assess its efficacy and safety in Parkinson's disease patients who were experiencing wearing-off phenomenon, a motor complication, while receiving Levodopa therapy alone or in combination with other anti-Parkinson's disease drugs. Based on the results of these studies, the new drug application (NDA) for registration of KW-6002 in the US was submitted to the Food and Drug Administration (FDA) in April 2007. On February 25, 2008, Kyowa received an action letter from the FDA. Subsequent to discussions with FDA, Kyowa decided to await the results of the ongoing Japanese phase 2b study of KW-6002 as adjunctive therapy to Levodopa, and then comprehensively examine and determine a path forward for KW-6002.

The results of the phase-2b study in Japan have recently become available and demonstrate the efficacy of KW-6002 compared with placebo, warranting further clinical investigation in Japan.

For the development and commercialization of KW-6002 in overseas markets, is pursuing out-licensing opportunities.

We believe that KW-6002 will offer a new therapeutic option for Parkinson's disease and provide clinical benefit to patients suffering from wearing off phenomenon and other symptoms.

Parkinson's disease is a progressive neurodegenerative disorder which is characterized by motor symptoms such as slowness of movement, rigidity, tremor and postural instability. The symptoms of this disease result from the progressive degeneration of certain nerve cells located in a specific area in the brain leading to a shortage of the neurotransmitter dopamine. It results in decreased activation of dopamine receptors in the brain which is thought to cause the motor symptoms. The symptoms of Parkinson's disease are treated primarily by dopamine replacement therapy with Levodopa or dopamine agonists. Long term therapy with Levodopa is associated with motor complications such as the development of a shortening response to each dose, which is called 'wearing-off phenomenon', and involuntary movements.