Daiichi Sankyo brought patent infringement actions in Tokyo District Court against seven generics companies: Shiono Chemical Co, Taiyo Yakuhin Co, Takata Seiyaku Co, Nichi-Iko Pharmaceutical Co, Nihon Generic Co, Mylan Seiyaku, and Yoshindo and in Osaka District Court against six generics companies: Ohara Pharmaceutical Co, Sawai Pharmaceutical Co, Taisho Pharm, Choseido Pharmaceutical Co, Towa Pharmaceutical Co and Nipro Pharma.
The 13 companies noted above have all received approvals and are currently scheduled to market and sell generic versions of levofloxacin hydrate.
The patent for levofloxacin hydrate was originally extended until May 27, 2011 with the additional indication for Legionella pneumophila. However, late November 2008, the Japan Patent Office invalidated the extension beyond December 25, 2008.
Daiichi Sankyo appealed the invalidation of the ruling to the Intellectual Property High Court on December 24, 2008 and the case is currently under review. The company brought the litigations against generics companies as a measure to swiftly halt the manufacture and sales of levofloxacin hydrate if the invalidation would be overturned.