Astellas US LLC and Astellas Pharma US, Inc. ("Astellas") along with ITEM Development AB ("Item") announced today that they have filed a patent infringement lawsuit in the United States against Sicor Inc., Sicor Pharmaceuticals, Inc., Teva Pharmaceuticals USA, Inc. and Teva Pharmaceutical Industries, Ltd. (collectively, "Sicor") regarding submission of an abbreviated new drug application ("ANDA") for a generic version of Adenoscan® (adenosine injection), a pharmacologic stress agent indicated as an adjunct to thallium-201 myocardial perfusion scintigraphy in patients unable to exercise adequately. Astellas is the exclusive licensee of certain rights under Item's US patent No. 5,731,296 ("'296 Patent") and has marketed Adenoscan® in the US since 1995. The patent infringement action was filed in the US District Court in Delaware on May 26, 2005, requesting, among other things, an order prohibiting approval of Sicor's ANDA prior to the expiration date of the '296 Patent.

Astellas US LLC and Astellas Pharma US, Inc. are US subsidiaries of Tokyo- based Astellas Pharma Inc., a research-based pharmaceutical company dedicated to improving the health of people around the world through innovative pharmaceutical products. Astellas Pharma Inc. ranks among the top 20 pharmaceutical companies in the world. For more information on Astellas, please go to http://www.astellas.com/us .