Kyowa Hakko Kirin Co is putting its anti-Parkinson's disease drug istradefylline into late-stage trials in Japan and is looking for partners to develop the compound overseas.

Kyowa started the clinical evaluation of KW-6002 (istradefylline) in 1996, and has conducted Phase II and III studies in the USA and Europe to assess its efficacy and safety in Parkinson's disease patients who were experiencing “wearing-off phenomenon”. The latter is a motor complication, while receiving levodopa therapy alone or in combination with other anti-Parkinson's drugs, such as the development of a shortening response to each dose and involuntary movements.

Based on these studies, a New Drug Application US Food and Drug Administration in April 2007 but in February last year, Kyowa received an action letter from the agency. As a result, the Japanese drugmaker decided to wait for the results of the ongoing Japanese Phase IIb study of KW-6002 as adjunctive therapy to levodopa before determining a path forward.

Those results have recently become available, Kyowa said, and demonstrate the efficacy of KW-6002 compared with placebo. As for overseas markets, the company said it is “pursuing out-licensing opportunities.”