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Sunesis Pharmaceuticals and the Multiple Myeloma Research Consortium Form Collaboration to Study SNS-032 in Multiple Myeloma


South San Francisco, CA — December 19, 2007

Sunesis Pharmaceuticals, Inc. (Nasdaq: SNSS) and the Multiple Myeloma Research Consortium (MMRC) have entered into a collaboration to evaluate Sunesis' SNS-032 as a potential therapeutic for the treatment of multiple myeloma.

The MMRC collaboration is evaluating the preclinical activity of SNS-032 in multiple myeloma-relevant models and in primary disease tissue, extending non-clinical studies performed by Sunesis. Under the lead of Suzanne Trudel, MSc, M.D., Assistant Professor, Princess Margaret Hospital, University Health Network, these studies are also being conducted at four other MMRC-affiliated institutions: Dana-Farber Cancer Institute, H. Lee Moffitt Cancer Center & Research Institute, Mayo Clinic Cancer Center and Emory University. Data from these studies will facilitate the identification of relevant mechanism-based biomarkers of patient response to SNS-032 and may guide rational combination strategies in planned clinical trials of SNS-032 in multiple myeloma.

"We are excited to be working with the MMRC and world-renowned researchers in further elucidating the potential of SNS-032 for the treatment of multiple myeloma," said Daniel C. Adelman, M.D., Sunesis' Senior Vice President, Development and Chief Medical Officer. "This collaboration is providing us with access to cutting-edge disease models, and the resulting data should further define SNS-032's mechanism of action and the compound's potential benefits in this patient population. Importantly, the additional data gathered by these thought leaders will supplement our own research and allow us to optimize our clinical trial programs. Sunesis is currently conducting a Phase 1 clinical trial of SNS-032 in patients with multiple myeloma and chronic lymphocytic leukemia."

"There is an acute need to develop new, targeted therapies capable of attacking the underlying mechanisms responsible for making multiple myeloma so difficult to treat," said Kathy Giusti, Founder and Chief Executive Officer of the MMRC. "We are pleased to be working with Sunesis to advance research on SNS-032, which appears to be potentially well suited to the treatment of multiple myeloma and other B-cell malignancies. The MMRC is committed to conducting collaborations of this sort with industry to bring better, more effective treatments to myeloma patients as quickly as possible."

About SNS-032

SNS-032 is a potent, selective inhibitor of cyclin-dependent kinases (CDKs) 2, 7 and 9 that inhibits both cell cycle progression and transcription. SNS-032 has been shown in preclinical and clinical studies to deplete cells of key survival factors, including myeloid cell leukemia sequence 1, or MCL-1, a protein associated with cell survival, particularly in B-cell malignancies such as multiple myeloma. It is hypothesized that down regulation of survival proteins will provide clinical benefit in hematologic cancers by inducing apoptosis of malignant cells and disrupting tumor-stromal interactions requisite for maintaining these diseases.

About the Multiple Myeloma Research Consortium (MMRC)

The Multiple Myeloma Research Consortium (MMRC) is a 509a3 non-profit organization that integrates leading academic institutions to accelerate drug development in multiple myeloma. It is comprised of the MMRC and 13 member institutions: City of Hope Cancer Center, Dana-Farber Cancer Institute, Emory University's Winship Cancer Institute, Hackensack University Medical Center, H. Lee Moffitt Cancer Center & Research Institute, Mayo Clinic, Ohio State University, Roswell Park Cancer Institute, St. Vincent's Comprehensive Cancer Center of Saint Vincent Catholic Medical Centers of New York, University Health Network (Princess Margaret Hospital), University of Chicago, University of Michigan, and Washington University.

The MMRC was founded in 2004 by Kathy Giusti, a myeloma patient, and with the help of the scientific community, as an optimal research model to rapidly address critical challenges in accelerating drug development and explore opportunities in the most promising areas of myeloma research – genomics, compound validation, and clinical trials. The MMRC is the only consortium to join academic institutions through membership agreements, customized IT systems, and an integrated tissue bank. For more information, please visit www.themmrc.org.

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 www.sunesis.com.


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

Safe Harbor Statement

This press release contains forward-looking statements including without limitation statements related to the potential safety and efficacy of SNS-032 and planned additional clinical testing and development efforts. Words such as "will," "may," "should," "potential," "appears" and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon Sunesis' current expectations. Forward-looking statements involve risks and uncertainties. Sunesis' actual results and the timing of events 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 Sunesis' drug discovery and development activities could be halted significantly or delayed for various reasons, the risk that Sunesis' clinical trials for SNS-032 may not demonstrate safety or efficacy or lead to regulatory approval, the risk that preliminary data and trends may not be predictive of future data or results, the risk that Sunesis' preclinical studies and clinical trials may not satisfy the requirements of the FDA or other regulatory agencies, risks related to the conduct of Sunesis' clinical trials and manufacturing of SNS-032 and risks related to Sunesis' need for additional funding. 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 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.

SUNESIS CONTACTS:

Investors
Eric Bjerkholt
SVP, Corp. Development & Finance
Sunesis Pharmaceuticals, Inc.
650-266-3717

Media
Karen L. Bergman or
Michelle Corral
BCC Partners
650-575-1509 or 415-794-8662

MMRC CONTACT:

Steven Young
Executive Director
203-652-0220