For Immediate Release

Company name: DAIICHI SANKYO COMPANY, LIMITED
Representative: Takashi Shoda, President and Representative Director
(Code no.: 4568, First Section, Tokyo, Osaka and Nagoya Stock Exchanges)
Please address inquiries to Toshio Takahashi, Corporate Officer in Charge,
Corporate Communications Department
Telephone: +81-3-6225-1126
http://www.daiichisankyo.com/

DAIICHI SANKYO COMMENCES PATENT LITIGATION AGAINST MYLAN IN THE UNITED STATES

Tokyo, June 26, 2007 － DAIICHI SANKYO COMPANY, LIMITED (hereinafter"Daiichi Sankyo"), announces that Daiichi Sankyo and its U.S. subsidiary, DAIICHISANKYO, INC. (New Jersey, hereinafter "DSI"), commenced litigation on June 22,2007, against Mylan* in the United States District Court for the District of New Jersey for infringement of Daiichi Sankyo's U.S. patent (hereinafter "Patent") covering olmesartan medoxomil, one of the active ingredients in Daiichi Sankyo's antihypertensive drug, Benicar HCT(R). Mylan has filed an Abbreviated New Drug Application ("ANDA") with the United States Food and Drug Administration seeking to market a generic version of Benicar HCT(R).

 

Daiichi Sankyo and DSI intend to vigorously defend the Patent, which expires in April 2016 in the United States.

 

Olmesartan medoxomil, one of the active ingredients in Benicar HCT(R), is an angiotensin II receptor antagonist that Daiichi Sankyo independently developed, and is marketed in over 35 countries as an antihypertensive drug which suppresses vasoconstriction by affecting the rennin-angiotensin system to control blood pressure.

*Note:
"Mylan" refers to Mylan Pharmaceuticals, Inc. (HQ: West Virginia) and its parent company, Mylan Laboratories, Inc. (HQ: Pennsylvania).