PRINCETON, N.J.--(BUSINESS WIRE)--March 7, 2006--Kyowa Hakko Kogyo Co., Ltd., located in Chiyoda-ku, Tokyo, Japan (President: Dr. Yuzuru Matsuda) has completed three Phase III clinical studies of KW-6002 (generic (INN) name: Istradefylline), an agent developed in-house for the treatment of Parkinson's Disease.