Kyowa Hakko Kirin returns rights to Busulfex to Otsuka

Japanese drugmaker Kyowa Hakko Kirin (TYO: 4151) has reached agreement on returning development and marketing rights for cancer drug Busulfex (busulfan) to Otsuka Pharmaceuticals (TYO: 4578), for use as a part of conditioning regimen prior to hematopoietic progenitor cell transplantation. As a result, Kyowa Hakko Kirin will receive 2 billion yen ($25.3 million).

Otsuka acquired rights to the drug from USA-based PDL Pharma for $200 million (The Pharma Letter December 24, 2007). 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).

Kyowa Hakko Kirin had in-licensed 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 on April 1, 2013.