TOKYO, February 28 /PRNewswire/ --

Kyowa Hakko Kogyo Co., Ltd. President: Dr. Yuzuru Matsuda announced that Kyowa Pharmaceutical, Inc. (New Jersey, United States), its wholly owned U.S. subsidiary, received on February 25, 2008 a Not approvable letter from the U.S. Food and Drug Administration (FDA) for istradefylline (KW-6002), its investigational drug for the treatment of Parkinson's disease.

In the not approvable letter FDA expressed concern if the efficacy findings support clinical utility of istradefylline (KW-6002). The FDA requested an overall summary of nonclinical mineralization findings. Additionally, the FDA asked for clinical pharmacology follow-up information as a Phase 4 commitment.

After closely examining the FDA's response, Kyowa Hakko will work closely with FDA and conduct a comprehensive discussion to determine a path forward for istradefylline (KW-6002).

Istradefylline (KW-6002) has a novel mechanism of action that antagonizes the adenosine A2A receptor. It has been under FDA review as adjunctive therapy to levodopa/carbidopa for the treatment of idiopathic Parkinson's disease to improve motor function in patients who experience motor response complications.

Kyowa Hakko is a biotechnology-based company focused on two businesses: pharmaceutical operations engaged in the research and development, manufacturing, and marketing of prescription drugs; and bio-chemical operations that handle a variety of products such as amino acids, nucleic acids, and nutritional supplements/healthcare products. Its pharmaceutical business places emphasis on research and development in the fields of oncology, allergy, and the central nervous system. In Japan, Kyowa Hakko is marketing medications for a wide range of diseases, including allergy, hypertension, angina pectoris, and cancer. With the aim of penetrating the global market, Kyowa Hakko has overseas development bases in the U.S. (Kyowa Pharmaceutical, Inc. and BioWa, Inc.) and in the U.K. (Kyowa Hakko U.K. Ltd.). In the U.S., U.K., and China, they are pushing ahead with the clinical development of new drug candidates as well as the therapeutic antibody business based on Kyowa Hakko's proprietary technology (POTELLIGENT) that enhances the activity of antibodies.

Last autumn, Kyowa Hakko announced that the Kyowa Hakko group and the Kirin group entered into an agreement to form a strategic business/capital alliance. Through this tie-up, the two groups will endeavor to build a global leader in the research and development-driven life sciences business based in Japan, which is centered on pharmaceutical operations with strengths in biotechnology. The new company "Kyowa Hakko Kirin Co., Ltd." will start operating on October 1, 2008.