Sunesis Pharmaceuticals Announces Milestone Payment from Inflammation Collaboration

SOUTH SAN FRANCISCO, Calif., Feb. 20 /PRNewswire-FirstCall/ -- Sunesis Pharmaceuticals, Inc. (Nasdaq: SNSS) today announced that it has earned a preclinical milestone payment from Johnson & Johnson Pharmaceutical Research & Development, L.L.C. (J&JPRD) under the companies' drug discovery collaboration agreement.

The two companies entered into a research collaboration in May 2002 to discover oral small molecule enzyme inhibitors for the treatment of major chronic inflammatory and autoimmune diseases. The recent milestone payment was triggered by J&JPRD's selection of a compound targeting the Cathepsin S enzyme as a development candidate. Under the terms of the collaboration agreement, Sunesis has the potential to receive additional development milestone payments from J&JPRD, as well as royalty payments based on future product sales.

"We believe that a small molecule inhibitor of Cathepsin S will provide a useful approach to treating certain inflammatory conditions and we are pleased by J&JPRD's advancement of a compound from our collaboration into development," said Bob McDowell, Ph.D., Vice President of Research at Sunesis.

About Cathepsin S

Cathepsin S is an enzyme involved in the activation of immune system T-cells. Inhibiting inappropriate activation of T-cells may lead to novel treatments of certain inflammatory and autoimmune diseases, such as rheumatoid arthritis and multiple sclerosis.

About Sunesis Pharmaceuticals

Sunesis is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel small molecule therapeutics for oncology and other serious diseases. Sunesis has built a broad product candidate portfolio through internal discovery and in-licensing of novel cancer therapeutics. Sunesis is advancing its product candidates through in-house research and development efforts and strategic collaborations with leading pharmaceutical and biopharmaceutical companies. For additional information on Sunesis Pharmaceuticals, please visit http://www.sunesis.com.

SUNESIS and the logo are trademarks of Sunesis Pharmaceuticals, Inc.

Safe Harbor Statement

This press release contains forward-looking statements regarding Sunesis' collaboration with J&JPRD and the potential for Sunesis to receive additional milestone payments and royalties from J&JPRD. These forward-looking statements involve risks and uncertainties. Sunesis' actual results could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, the risk that J&JPRD's research and development activities with respect to collaboration compounds could be halted or delayed for various reasons or that there may never be sales from a resulting product. Sunesis may never receive any additional milestone payments or royalties from J&JPRD in connection with this collaboration. These and other risk factors are discussed under "Risk Factors" and elsewhere in Sunesis' annual report on Form 10-K for the year ended December 31, 2006, Sunesis' most recent quarterly report on Form 10-Q and other filings with the Securities and Exchange Commission. Sunesis expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in the company's expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.

SOURCE Sunesis Pharmaceuticals, Inc.