Sunesis Pharmaceuticals Added to Russell Microcap® Index

SOUTH SAN FRANCISCO, Calif., June 26, 2017 -- Sunesis Pharmaceuticals, Inc. (Nasdaq:SNSS) today announced that it was added to the Russell Microcap® Index when the Russell Investment Group reconstituted its family of U.S. indexes effective today, June 26, 2017.

Membership in the Russell Microcap Index, which remains in place for one year, means automatic inclusion in the appropriate growth and value style indexes. FTSE Russell determines membership for its Russell indexes primarily by objective, market-capitalization rankings and style attributes.

About Sunesis Pharmaceuticals

Sunesis is a biopharmaceutical company focused on the development and commercialization of new oncology therapeutics for the potential treatment of solid and hematologic cancers. Sunesis has built a highly-experienced cancer drug development organization committed to improving the lives of people with cancer. Currently, the company is focused on advancing its novel kinase-inhibitor pipeline, which includes its proprietary non-covalent BTK-inhibitor, SNS-062.

For additional information on Sunesis, please visit http://www.sunesis.com.

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

This press release contains forward-looking statements, including statements related to the continued development and commercialization of vosaroxin, the timing of our Phase 1b/2 trial of SNS-062, and the sufficiency of Sunesis’ cash and funding into June 2018. Words such as “advance,” “continue,” “expect,” “will” 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 may not be able to receive regulatory approval of vosaroxin in the U.S. or Europe, that Sunesis' development activities for SNS-062 or vosaroxin could be otherwise halted or significantly delayed for various reasons, risks related to Sunesis' need for substantial additional funding to complete the development and commercialization of vosaroxin and other product candidates, including SNS-062, the risk that Sunesis' clinical studies for vosaroxin or other product candidates, including SNS-062 or its pipeline of kinase inhibitors, may not demonstrate safety or efficacy or lead to regulatory approval, the risk that data to date and trends may not be predictive of future data or results, risks related to the timing or conduct of Sunesis' clinical trials, and risks related to Sunesis' ability to raise the capital that it believes to be accessible and is required to fully finance the development and commercialization of SNS-062, vosaroxin and other product candidates. These and other risk factors are discussed under "Risk Factors" and elsewhere in Sunesis' Quarterly Report on Form 10-Q for the quarter ended March 31, 2017 and Sunesis' 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 Sunesis' expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.

Investor and Media Inquiries:
Maeve Conneighton
Argot Partners
212-600-1902

Dan Swisher
Sunesis Pharmaceuticals Inc.
650-266-3715