Quintessence Biosciences: Patients now enrolling in phase I human trial for Quintessence Biosciences cancer drug, QBI-139

MADISON, WISCONSIN— Quintessence Biosciences, Inc. announced today that the Phase I trial of its Investigational New Drug (IND), QBI-139, has begun enrolling patients. The Phase I Trial is taking place at the University of Wisconsin Paul P. Carbone Comprehensive Cancer Center (UWCCC) in Madison. QBI-139 is the first of the Company’s EVade™ Ribonuclease drug candidates to reach the clinic.

Unlike conventional chemotherapies, the EVade™ Ribonuclease technology provides an opportunity to attack RNA in cancer cells, an exciting new drug target. QBI-139 is nearly identical to a human protein, pancreatic ribonuclease 1. In preclinical disease models, QBI-139 has shown significant tumor growth inhibition against human pancreatic, non-small cell lung, prostate, and ovarian solid tumors.

Quintessence Biosciences will not directly enroll patients. Potential enrollees should contact UWCCC Cancer Connect by email ([email protected]) or by phone (800-622-8922 or 608-262-5223) to request information (Unique Protocol ID # CO 08912).

The attached document outlines basic information for potential enrollees. The information is also available on the Quintessence Biosciences, Inc. web site at http://www.quintbio.com.

“The start of the Phase I QBI-139 trial represents the culmination of years of research and an opportunity to demonstrate the promise of a new class of cancer therapies,” said Quintessence Biosciences President Dr. Laura Strong. “We are optimistic that QBI-139 will provide a new means to help patients with cancer. There is a clear need for drugs that attack cancer in new ways, and ribonuclease therapies are positioned to accomplish that goal.”

About Quintessence Biosciences, Inc.

Quintessence Biosciences, Inc. is a private biopharmaceutical company focused on development of proprietary cancer therapies based on the EVade™ Ribonuclease technology. In December 2008, Quintessence Biosciences received approval from the US Food and Drug Administration to enter a Phase 1 clinical trial on the Company’s first drug candidate, QBI-139. The company also has a pipeline of other EVade™ Ribonuclease products in preclinical research. For more information, visit http://www.quintbio.com.