Preliminary Results to Be Presented at American Transplant Congress

TOKYO, Japan | Apr 24, 2007 | Y’s Therapeutics, a privately held biopharmaceutical company, announced the completion of patient enrollment for its Phase II clinical trial of YSPSL for prevention of delayed graft function (DGF) in kidney transplant patients. The clinical trial enrolled 75 patients across 15 leading US transplant centers to evaluate the safety and efficacy of YSPSL (r-PSGL-Ig, recombinant P-selectin glycoprotein immunoglobulin) for prevention of DGF in patients undergoing cadaveric kidney transplantation.

"Completion of patient enrollment in this study is an important milestone for Y’s Therapeutics. We are very excited about potential for YSPSL and the future of this program," said Masanori Murayama, Representative Director, Y’s Therapeutics Co., Ltd. "The success of YSPSL in a variety of animal models, including recent data in percutaneous cardiac intervention (PCI), makes it an attractive investigational agent for development in other indications."

The results of the first portion of the study, which was open labeled, will be given as an oral presentation during the American Transplant Congress in San Francisco. The paper, entitled "YSPSL (rPSGL-Ig) for the Prevention of Delayed Graft Function (DGF): Preliminary Results of Ongoing Dose Escalation and Efficacy Study," will be presented during the "Kidney Immunosuppression: Newest Agents" session, beginning at 4:00 PM Sunday, May 6.

The results from the Phase II clinical trial, including the placebo-controlled, blinded portion of the study, will be available after analysis of the six-month follow-up data of all enrolled patients in the study.

About YSPSL

YSPSL is a recombinant molecule resulting from fusion of P-selectin glycoprotein ligand (PSGL-1) and human IgG1. The underlying cause of DGF is ischemia-reperfusion injury (I/R injury), which happens when blood re-flows into ischemic tissue, in this case the newly transplanted organ. During ischemia reperfusion, P-selectin appears on the activated endothelium (blood vessel walls) and the binding to its ligand on leukocytes is the critical first step in inflammation. YSPSL has been demonstrated in a number of animal models to block this selectin/ligand interaction, thereby preventing tissue damage from inappropriate inflammation. Administration of YSPSL in animal models of transplantation suggests it may also up-regulate beneficial genes such as heme oxygenase-1 that appear to protect organs from I/R Injury.

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 is seeking collaborative relationships, including out-licensing of product rights and creation of joint ventures, for late-stage development, manufacturing and commercialization of its portfolio products. The company currently has several projects in its clinical and preclinical pipeline. Y’s has operations in two locations, Y’s Therapeutics Co., Ltd., of Tokyo, Japan, and Y’s Therapeutics, Inc., of Burlingame, CA.

SOURCE: Y’s Therapeutics