Kyowa Hakko Kirin Announces Results of Phase lll Clinical Study of KW-6002 (Istradefylline) for Parkinson's Disease in Japan

Tokyo, Japan, May 10, 2011 --- Kyowa Hakko Kirin Co., Ltd. ("Kyowa Hakko Kirin") announced today that unblinded results have been obtained from a Phase lll clinical study in Japan of a new chemical entity being developed for treatment for Parkinson's disease, KW-6002 (generic name: istradefylline).

This study was to evaluate the efficacy of KW-6002 (20 mg or 40 mg once a daily treatment for 12 weeks) in Parkinson's disease patients with motor response complications, such as "wearing-off phenomenon", on levodopa therapy, in comparison with placebo, and the safety of both doses was assessed.

The primary outcome variable was the change from baseline at endpoint in daily off-time, and the groups treated by 20 and 40 mg doses of KW-6002 both demonstrated a statistically significant reduction of off-time compared with the placebo group (daily off-time reduction from baseline at endpoint: placebo group, -0.23 hours; 20 mg group, -0.99 hours (p=0.003); 40 mg group, -0.96 hours (p=0.003)). In terms of the safety, KW-6002 was well tolerated at both 20 and 40 mg doses.

We have been developing this antiparkinsonian agent, as a novel mechanism of action, which is a selective adenosine A2A receptor　antagonist. We will be preparing a new drug application of KW-6002 in Japan.

Kyowa Hakko Kirin, we believe that KW-6002 becomes to be a new option in the treatment alternatives for Parkinson's disease, contributing to improve the symptoms of patients who are experiencing wearing-off.

Study design summary

Clinical study design:

A multicenter, 12-week, placebo-controlled, randomized, double-blind, parallel-group, confirmatory comparative trial

Subjects:

Patients with Parkinson's disease who are being treated with levodopa and who have motor complications. Placebo group: 126 subjects, 20 mg group: 123 subjects, 40 mg group: 124 subjects.

Primary endpoint:

Off time per day