Japan, November 29, 2005 - Astellas Pharma Inc. ("Astellas"; headquarters: Tokyo; President and CEO: Toichi Takenaka) today announced that Astellas filed a patent infringement lawsuit on November 29 with the Tokyo District Court against Toyo Pharmar Co., Ltd. ("Toyo Pharmar"; headquarters: Kanazawa) and ASKA Pharmaceutical Co., Ltd. ("ASKA Pharmaceutical"; headquarters: Tokyo) demanding that Toyo Pharmar and ASKA Pharmaceutical stop infringing Astellas' patent rights on its modified release formulation of tamsulosin hydrochloride (brand name: Harnal® 0.1 mg/0.2 mg Capsules).

Tamsulosin hydrochloride is an alfa-1 blocker selective for the prostatic and urethral smooth muscle developed by Astellas (former Yamanouchi Pharmaceutical Co., Ltd.). It relaxes urethral hypertonia and improves the functional symptoms of benign prostatic hyperplasia without any significant effect on the vascular smooth muscle that affects blood pressure. In Japan, it was launched under the brand name of Harnal® Capsule in 1993 and has been used as a drug of first choice in the treatment of functional symptoms of benign prostatic hyperplasia.

Toyo Pharmar obtained an NHI price for the capsule preparation of tamsulosin hydrochloride, Restream® Capsules 0.1 mg/0.2 mg, in July 2005 and has been marketing it through ASKA Pharmaceutical, while Astellas is the holder of a formulation patent on tamsulosin hydrochloride that is valid until March 2006. In the belief that their capsule formulations infringe our patent rights, Astellas filed a lawsuit with the Tokyo District Court against the two companies demanding that they stop manufacturing and marketing their products and pay damages to Astellas.

Astellas independently investigates and analyzes at its research center whether the patent rights on its in-house products are infringed. Astellas will take any appropriate measures, including lawsuits, to eliminate infringements whenever any evidence or likelihood of infringement is found.