Chugai Pharmaceutical Co., Ltd. (Head office: Chuo-ku, Tokyo / Chairman & CEO: Osamu Nagayama) announces that a lawsuit was filed against Chugai at the Tokyo District Court as follows.

1. Service of Complaint
   May 6, 2016
2. Reasons and Background for the Action
   It is alleged by Baxalta that the new drug candidate under development by Chugai for the treatment of hemophilia A, emicizumab (development code: ACE910), is infringing one of its patent (patent number 4313531) and thus it filed for an injunction against manufacture, usage, transfer, exportation, and offer of any transfer regarding emicizumab, and requested cessation.
3. Party Who Filed the Complaint
   

   (1)Name:	Baxalta Incorporated Baxalta GmbH
   (2)Address:	1200 Lakeside Drive Bannockburn, IL 60015, USA Thurganerstrasse 130 Glattpark Opfikon 8152, Switzerland

4. Contents of the Complaint
   Injunctive order against infringement of patent right
5. Prospects
   The plaintiff has articulated in their complaint that the act such as manufacturing and usage of emicizumab for clinical trials in Japan infringes its patent, and emicizumab has a potential to be manufactured and sold in the future. However, Chugai is confident that emicizumab does not infringe the plaintiff’s patent, and plan to vigorously pursue our defense through the entire court process to prove non-infringement.
   Therefore, no changes are expected to be made to the financial prospects of fiscal year 2016.