Kyowa Hakko Kirin returns to Otsuka Pharmaceutical the rights to develop and market Busulfex^®, for use as a part of conditioning regimen prior to hematopoietic progenitor cell transplantation, in Japan and in Asian Countries & Regions

Tokyo, Japan, September 14, 2012 --- Otsuka Pharmaceutical Co., Ltd. ("Otsuka Pharmaceutical") and Kyowa Hakko Kirin Co., Ltd. ("Kyowa Hakko Kirin") today announced the agreement on returning development and marketing rights of Busulfex^®, for use as a part of conditioning regimen prior to hematopoietic progenitor cell transplantation, from Kyowa Hakko Kirin back to its original licensor Otsuka Pharmaceutical. Busulfex^® is currently developed and marketed by Kyowa Hakko Kirin in Japan and in six Asian countries and regions (China, Korea, Taiwan, Singapore, Malaysia and Thailand).

Otsuka Pharmaceutical is the distributor and the original licensor of all global businesses encircling Busulfex^®. Kyowa Hakko Kirin had licensed-in the development rights and dealership within Japan and in Asian countries and regions. The contract will terminate as of March 31, 2013, and Kyowa Hakko Kirin will return the rights to Otsuka Pharmaceutical thereafter April 1, 2013. Kyowa Hakko Kirin will receive JPY 2.1 billion in accordance with the returning of Busulfex^®.

Busulfex^® is currently sold in 57 countries and regions, and has now become established as the standard drug as a conditioning agent administered prior to bone marrow transplants, an important treatment together with radiotherapy. Busulfex^® will be developed and marketed in nine countries and regions including the US and Canada, once its development and marketing rights within Japan and in Asian countries and regions are returned to Otsuka Pharmaceutical.

Otsuka Pharmaceutical has been conducting the global business encircling Busulfex^® since March 2008. Busulfex^® is marketed by Otsuka Pharmaceutical's local affiliate in the US and in Canada, and Kyowa Hakko Kirin and its local affiliates market Busulfex^® in Asian countries and regions including Japan. Laboratoire Pierre Fabre markets Busulfex^® in Europe, Latin America and Africa.

Upon the returning of Busulfex^® from Kyowa Hakko Kirin to Otsuka Pharmaceutical, both companies will take all possible measures to ensure the fluent transfer of business operations, including product distribution and product communications.