Conclusion of Exclusive Licensing Agreement of YSCMA, Humanized Anti-CD26 Monoclonal Antibody, for Development and Sales in Japan

Y's Therapeutics Co., Ltd.
Kissei Pharmaceutical Co., Ltd.

Y's Therapeutics Co., Ltd. and Kissei Pharmaceutical Co., Ltd. today announced an exclusive licensing agreement in Japan to develop and commercialize YSCMA, Y's Therapeutics' humanized anti-CD26 monoclonal antibody. Under the terms of this agreement, Kissei Pharmaceutical will develop and commercialize YSCMA for the treatment of malignant mesothelioma in Japan.

CD26 is a transmembrane glycoprotein, which is highly expressed on some cancer cells. The humanized anti-CD26 monoclonal antibody is developed for the treatment of solid tumors including malignant mesothelioma and hematological malignancies. It binds to CD26 specifically, and non-clinical studies conducted by Y's showed it had clear antitumor effect.

About YSCMA(YS110)
YSCMA (alternate name; YS110) is Y's Therapeutics' Anti-CD26 therapeutic antibody targeted for the treatment of solid tumors and hematological malignancies. The target antigen, CD26, is a transmembrane glycoprotein found on selected tissues, and is highly expressed on certain cancer cells. YS110 has demonstrated anti-tumor effects in preclinical animal models. An IND was filed and cleared by the United States FDA in Feb 2008 for a Phase 1 study in oncology. Y's Therapeutics intends to file an IMPD submission in France in preparation for a planned study in malignant mesothelioma.

About Malignant Mesothelioma in Japan
Malignant mesothelioma is a cancer occurring mainly in the lung and pleura, and is often associated with exposure to asbestos fibers. The disease is characterized by a long latency period, with malignant mesothelioma often diagnosed 10-40 years following asbestos exposure. Currently, the prognosis for malignant mesothelioma patients is poor, and approximately 1,000 patients lose their lives in Japan every year. Although the number of patients is relatively small at present, it is believed that there will be a substantial increase in future patient numbers as a large amount of asbestos was employed in Japan until the early 1990's. Because of the prospective incidence, seriousness of malignant mesothelioma, and lack of currently available therapies, new therapeutic approaches are needed.

About Y's Therapeuticｓ
Y's Therapeutics (http://www.ysthera.com) is a privately held biopharmaceutical company engaged in the R&D of novel therapeutics for the treatment of inflammation-mediated diseases, cancer, and other unmet medical needs. Y's focuses on the development of preclinical and early-stage clinical projects pursued through research collaborations and in-licensing opportunities from academic institutions and biotech companies. Y's has operations in two locations, Y's Therapeutics Co., Ltd., of Tokyo, Japan, and Y's Therapeutics, Inc., of Burlingame, CA.

Y's Therapeutics Co., Limited (Symbol: Private)
Fujiwara Building, 4F, 1-10-11 Ebisu-Nishi, Shibuya-ku Tokyo
Japan, 150-0021
http://www.ysthera.com/

About Kissei Pharmaceutical
Kissei Pharmaceutical Co., Ltd., headquartered in Matsumoto, Nagano prefecture, founded in 1946, is a research and development oriented pharmaceutical company that manufacture and sells brand pharmaceutical products. Kissei is primarily focused on two important fields of new drug research: genitourinary system and metabolism & endocrinology. In addition, Kissei is currently concentrating on therapeutic areas of unmet medical needs and biotechnology-based pharmaceuticals.

Kissei Pharmaceutical Co., Ltd. (Symbol: Stock Code Number: 4547 (The Tokyo Stock Exchange))
19-48, Yoshino, Matsumoto City, Nagano Prefecture
Japan, 399-8710
http://www.kissei.co.jp/