Quintessence Biosciences: Presents pre-clinical combination data for clinical candidate QBI-139

Contact: Dr. Laura Strong, President and Chief Operating Officer, 608-441-2950

WASHINGTON DC AND MADISON, WI – Quintessence today announced that data for their lead EVade™ Ribonuclease, called QBI-139, will be presented at the American Association for Cancer Research 101st Annual Meeting. QBI-139 is a protein therapeutic that targets the RNA in cancer cells. The data presented will focus on the potency of QBI-139 in combination with the standard of care agent cisplatin in a preclinical model of non-small cell lung cancer. QBI-139 has already shown broad single agent activity against a variety of cancers with significant unmet need, such as non-small cell lung and pancreatic cancers.

About Quintessence Biosciences, Inc.

Quintessence Biosciences, Inc. is a private biopharmaceutical company focused on development of cancer therapies based on the proprietary EVade™ Ribonuclease technology. Quintessence’s first product candidate, QBI- 139, is in a Phase 1 clinical trial at The University of Texas M.D. Anderson Cancer Center and The University of Wisconsin Carbone Cancer Center. The company also has a pipeline of other EVade™ Ribonuclease products in preclinical research. For more information, visit http://www.quintbio.com.

About the American Association for Cancer Research Annual Meeting

The AACR 101st Annual Meeting 2010, April 17-21 is being held in Washington DC. The AACR Annual Meeting attracts more than 17,000 participants who share the latest discoveries and developments in the field. This year’s theme is “Conquering Cancer Through Discovery Research”. The AACR expects approximately 6,300 proffered papers will be presented as posters and short talks, as well as hundreds of invited talks from preeminent leaders in the global cancer community. For more information, visit http://www.aacr.org/home/scientists/meetings–workshops/aacr-101st-annual-meeting-2010.aspx.