Quark’s Novel siRNA Structures Exhibit Stability and Activity in vitro 

Fremont, California, August 27, 2007 – Quark Pharmaceuticals, Inc., a clinical-stage biopharmaceutical company focused on discovering and developing novel RNA interference-based therapeutics, announced today that the Company has filed a patent application covering a number of novel chemical modifications that confer to the siRNA molecule stability and excellent penetration into the human cells tested.

“With the submission of this patent application, we believe we have provided significant additional protection for our pipeline program,” said Daniel Zurr, President and CEO of Quark. “Filing of this patent application marks a significant step in our efforts to solidify our position as a leader in the RNAi therapeutics space, as the new structures allow us more flexibility with regard to intellectual property.. We believe our future siRNA therapeutics will be less dependent on in-licensed rights to RNAi technology. This patent application adds the element of structural design to our expertise in identifying clinically attractive drug targets using a proprietary discovery platform and local or systemic delivery.”

The patent application relates to new classes of chemically modified siRNA structures that have been tested in cell culture and have demonstrated enhanced stability, silencing activity, and cell penetration. Several new molecules are currently in preclinical testing. This research is part of Quark’s program to develop novel synthetic siRNA patterns with drug-like properties as well as improved targeted delivery systems.

Currently, Quark owns or controls 30 issued U.S. and European patents, and has 200 patent applications pending, covering its technology, drug candidates, target genes and pipeline products.

About Quark Pharmaceuticals, Inc.

Quark Pharmaceuticals is a clinical-stage biopharmaceutical company focused on developing drug candidates that work through the recently discovered cellular mechanism known as RNA interference, or RNAi. Quark is able to discover novel therapeutic targets based on its proprietary gene discovery platform, BiFARTM. This, combined with its ability to design and successfully deliver synthetic molecules of the new class of RNAi therapeutics known as small-interfering RNA, or siRNA, to specific organs in the body, enables the Company to rapidly develop drug candidates. Quark has two internally discovered and developed lead candidates: RTP801i-14 in Phase 1 clinical trial for the treatment of wet age-related macular degeneration, and AKIi-5 for the prevention of acute renal failure. The Company has out-licensed certain siRNA drug candidates to Pfizer on an exclusive worldwide basis. These drug candidates are designed to inhibit Quark’s proprietary target gene RTP801, including RTP801i-14.. Quark has, in addition, a product candidate portfolio of RNAi therapeutics based on novel targets and therapeutic concepts discovered using BiFARTM and designed for the treatment of oxidative stress associated diseases of the inner ear, lungs and additional organs of the body.

Quark is headquartered in Fremont, California and operates research and development facilities in Boulder, Colorado and Ness-Ziona, Israel. Additional information is available on the Company website at www.quarkpharma.com.