FREMONT, Calif., May 4, 2010 – Quark Pharmaceuticals, Inc., the world leader in clinical development of RNAi-based therapeutics, announced today that data from the Phase I QPI-1002 (I5NP) DGF Study (NCT#00802347) will be presented at the 2010 American Transplant Congress, taking place May 1-5 in San Diego, California. QPI-1002, the first systemically administered siRNA drug in humans, is designed to temporarily inhibit expression of the p53 stress-response gene. QPI-1002 is in clinical development for the prophylaxis of Delayed Graft Function (DGF) in kidney transplant recipients and has been granted U.S. orphan drug designation.

At the conference, A. Osama Gaber, M.D., F.A.C.S, Director of Transplant Surgery at the Methodist Hospital in Houston TX, an investigator in the study, will discuss the Phase I QPI-1002 results in a presentation titled, “Safety and Tolerability of Intravenous QPI-1002, a siRNA, for Prophylaxis of Delayed Graft Function (DGF) in Deceased Donor Renal Allograft Recipients at Increased Risk of DGF: Initial Results from a Double-Blind, Phase I First-in-Human Study.”

DGF is a significant problem for 24% of all recipients of deceased donor kidneys and 33% of patients who receive kidneys from deceased donors with expanded criteria per UNOS. The randomized, placebo-controlled, dose escalation Phase I study evaluated QPI-1002 in 40 transplant recipients of kidneys from deceased donors, including expanded criteria donors, and its results are now under analysis by Quark Pharmaceuticals. Safety data show no dose-limiting toxicities in any cohort and support continued evaluation of QPI-1002 for prophylaxis of DGF in deceased donor transplants.

Dr. Gaber said, “Recipients of deceased donor kidneys, particularly those undergoing transplant from expanded criteria donors, are at increased risk for DGF. Current strategies to decrease the rate of DGF focus on donor management, organ procurement and preservation techniques, recipient fluid management, and certain pharmacological agents. Quark’s product, QPI-1002, represents a truly unique approach by directly targeting p53, an underlying trigger of DGF. By temporarily inhibiting p53, QPI-1002 has the potential to decrease apoptosis, allowing natural cellular repair to preserve organ function following transplant.”

Daniel Zurr, Ph.D., President and Chief Executive Officer of Quark Pharmaceuticals, said, “We are encouraged by the Phase I safety and tolerability results of QPI-1002 in recipients of deceased donor kidneys and gratified by the high level of interest from the renal transplant community. QPI-1002 is part of our long-term commitment to discovering and developing novel and clinically relevant siRNA compounds to address unmet medical needs. Quark has more siRNA drug candidates in the clinic than any other RNAi company in the industry, and plans to leverage the Phase I results to advance additional clinical studies of QPI-1002 in DGF.”

About Quark Pharmaceuticals, Inc.

Quark Pharmaceuticals, Inc. is a leader in the discovery and development of novel RNAi therapeutics. Quark has a fully integrated drug development platform that spans therapeutic target identification to drug development. The Company’s technology platform includes novel disease targets and siRNA structures and chemistry, providing Quark with freedom to operate in the siRNA intellectual property arena. Quark’s approach to delivery allows targeting of tissues and organs including the eye, kidney, ear, lung, spinal cord and brain.

One of Quark’s partners, Pfizer Inc, is currently evaluating PF-4523655 (RTP801i-14) in two Phase 2 clinical studies in patients with diabetic macular edema (DME) and age-related macular degeneration (AMD). PF-4523655 is a synthetic, chemically modified siRNA designed to inhibit the expression of the gene RTP801 that was discovered by Quark through the gene discovery platform BiFARTM. Quark’s development pipeline also features QPI-1002, the first systemically administered siRNA drug in human clinical trials. QPI-1002 is being evaluated for the prevention of acute kidney injury (AKI) following major cardiovascular surgery and the prophylaxis of delayed graft function after kidney transplantation. Enrollment was successfully completed recently in Phase I studies in these indications. For the structures of these products, Quark has obtained licenses from Silence Therapeutics and from Alnylam Pharmaceuticals.

In the first quarter of 2010, Quark began a Phase 1/2 study of a new synthetic siRNA, QPI-1007, as a neuroprotective agent for eye diseases. QPI-1007 utilizes a proprietary structure, developed in collaboration with BioSpring GmbH, with freedom to operate in the siRNA intellectual property arena. The structure and modifications utilized in QPI-1007 preserve RNAi activity while ameliorating potential off-target and immunostimulatory effects of siRNAs. In addition, Quark has a broad pipeline of siRNA drug candidates that have arisen from Quark’s research activities. The Company is committed to developing novel siRNA structures and expects to utilize these improvements to develop additional RNAi drug candidates based on the Company’s productive R&D engine.

Quark is headquartered in Fremont, California and operates research and development facilities in Boulder, Colorado and Ness-Ziona, Israel. Additional information is available atwww.quarkpharma.com.