Eisai to Acquire Morphotek

Morphotek, Inc.

Eisai to Acquire Morphotek

March 22, 2007

Eisai’s Dramatic Leap towards Biologic Therapeutics Evidenced by the Acquisition

Tokyo, Japan, Woodcliff Lake, NJ and Exton, PA, March [XX], 2007 – Eisai Co., Ltd. (Tokyo, “Eisai,” President and CEO: Haruo Naito) Eisai Corporation of North America (Woodcliff Lake, NJ, “ECA,” President: Hajime Shimizu) and Morphotek® Inc. (Exton, PA, “Morphotek,” CEO: Nicholas Nicolaides) today announce that ECA has signed a definitive agreement to acquire Morphotek for US$325 million after excess net cash.

Morphotek develops therapeutic monoclonal antibodies through the use of a proprietary human antibody technology, including Human MORPHODOMA® and LibradomaTM. The company is leveraging these technologies to enrich its pipeline that already includes therapeutic antibody leads for the treatment of cancer, rheumatoid arthritis, and infectious disease. Two of its programs are currently in early stage clinical trials for the treatment of ovarian cancer and pancreatic cancer, respectively, with several others in preclinical development.

Eisai currently has an extensive global oncology research program for discovering small molecule cancer targets, and upon completion of the acquisition, will expand its capabilities into the biologic therapeutics field. With this unique and strategic antibody technology acquisition, Eisai can meet a variety of medical needs of cancer patients, through the development of therapeutic antibodies, small-molecule anti-cancer drugs, and potential combinations of both.

Mr. Naito said, “I sincerely respect Dr. Nicolaides’ innovative and courageous endeavor in developing human monoclonal antibody therapeutics. He has made a tremendous contribution to that effort. By combining Morphotek’s proprietary technologies and promising therapeutic antibodies with Eisai’s existing research programs and infrastructure, we will be able to meet our goal of addressing the unmet medical needs of patients, especially cancer patients, all around the world. Morphotek’s rich pipeline, unique and proprietary antibody generation technology platform, and highly skilled management and scientific team will become the core of our R&D efforts in biologics.”

Dr. Nicolaides said, “Eisai’s substantial intellectual and managerial resources will enable us to accelerate the development of our current therapeutic antibody pipeline as well as develop a number of additional clinical compounds to targets accessed from our broad network of research collaborations and to those discovered by Eisai researchers globally.”

Ivor Royston, Chairman of Morphotek, added, “this is an excellent opportunity for Morphotek to join the Eisai organization and to further its founding mission of becoming a global leader in the development of innovative immunotherapies to treat serious diseases and to establish solutions for the health and well-being of people worldwide.”

Upon completion of the transaction, Morphotek will become part of Eisai’s growing global discovery and development research network, which is comprised of research laboratories in Japan, Europe and the U.S. The addition of Morphotek further extends Eisai’s research presence in the U.S., which includes the Eisai Research Institute of Boston, Inc., a discovery operation based in Andover, Massachusetts, Eisai Medical Research Inc., for clinical development, located in Ridgefield Park, New Jersey, and RTP laboratory for formulation research, North Carolina.

“Morphotek will enjoy its autonomy in Eisai’s discovery network but I will encourage close collaboration among all Eisai R&D member companies. We very much look forward to welcoming Morphotek to the Eisai family of companies,” Mr. Naito concluded.

This planned expansion of Eisai’s discovery, research and clinical capabilities complements Eisai’s establishment of its oncology sales and marketing operations in the United States under ECA. Aided in part through its recent acquisition of four oncology-related products from Ligand Pharmaceuticals in October 2006, which included the retention of key oncology personnel and expertise including a sales force, Eisai has developed its commercial oncology infrastructure and is well positioned to market new oncology products that originate from Eisai’s research and discovery efforts or through future acquisition, co-promotion or in-licensing opportunities.

The Morphotek acquisition, which has been approved by the boards of directors of ECA and Morphotek, is subject to clearance under the Hart-Scott-Rodino Antitrust Improvements Act and other customary closing conditions. It is expected to close sometime during Eisai’s first fiscal quarter of 2007.

Mitsubishi UFJ Securities Co., Ltd. and Montgomery & Co. LLC are acting as financial advisors and Sullivan & Cromwell LLP is acting as legal counsel to Eisai in this transaction.

Lehman Brothers Inc. is acting as financial advisor and Cozen O’Conner LLP is acting as legal counsel to Morphotek in this transaction.

About Eisai Co., Ltd.

Eisai Co., Ltd. is a research-based human health care (hhc) company that discovers, develops and markets products throughout the world. Eisai focuses its efforts in three areas of therapeutic focus: Integrative neuroscience including neurology and psychiatric medicines; gastrointestinal disorders; and integrative oncology including oncotherapy and supportive-care treatments. Through a global network of research facilities, manufacturing sites and marketing subsidiaries, Eisai actively participates in all aspects of the worldwide health care system. Eisai employs more than 9,000 people worldwide and forecasts the group sales of ¥668 billion in FY2006. More than 50% of the group sales is derived from overseas business. For more information, visit www.eisai.co.jp.

About Eisai Corporation of North America

Eisai Corporation of North America is a wholly owned subsidiary of Eisai Co., Ltd. and supports the activities of its operating companies in North America. These operating companies include: Eisai Research Institute of Boston, Inc., a discovery operation with strong organic chemistry capabilities; Eisai Medical Research Inc., for clinical development; Eisai Inc. for manufacturing and marketing/sales functions; and Eisai Machinery U.S.A. for marketing and maintenance of pharmaceutical manufacturing machinery.

About Morphotek

Morphotek®, which was founded in 2000 and is located in Exton, Pennsylvania, and employs 45 people; is a privately held biopharmaceutical company which discovers and develops monoclonal antibodies for oncology, inflammatory and infectious diseases through the use of a proprietary human antibody technology called Human MORPHODOMA®. The company has assembled a strong pipeline of lead products in the area of cancer, inflammation and infectious diseases. Morphotek’s most advanced programs are MORAb 003, in Phase I/II for ovarian cancer, and MORAb 009, in Phase I for pancreatic cancer. There are several programs in preclinical stage moving towards IND filing. Its partners to date have included world-renowned research laboratories and leading biopharmaceutical companies. For further information, visit www.morphotek.com.

Eisai Contact Information

Corporate Communications Department
Eisai Co., Ltd.
+81-3-3817-5120
webmaster@eisai.co.jp

ECA Contact Information

Cathy Pollini , Corporate Planning and Communications
Eisai Inc.
+1-201-746-2052
cathy_pollini@eisai.com

Morphotek Contact Information

Nicholas Nicolaides, President & CEO
Morphotek Inc.
+1-610-423-6100
nicolaides@morphotek.com