Quark Pharmaceuticals Receives FDA Approval of IND for Kidney Transplant siRNA Drug

Quark Pharmaceuticals Receives FDA Approval of IND for Kidney Transplant siRNA Drug

FREMONT, Calif., June 25 -- Quark Pharmaceuticals, Inc. today announced that the U.S. Food and Drug Administration (FDA) has approved the Company's Investigational New Drug (IND) application for its siRNA drug candidate, DGFi, in kidney transplantation. The Company expects its Phase I/II clinical study for prevention/treatment of Delayed Graft Function (DGF) in kidney transplant patients to begin in the second half of 2008.

DGFi is Quark's second product candidate to enter clinic trials that is systemically administered to patients. The first ever siRNA drug candidate to be delivered systemically in man was Quark's AKIi-5 which is in Phase I clinical trial for acute kidney injury.

The Phase I/II will be a multi center study in which the safety and tolerability of escalating doses of DGFi by a single IV injection in renal transplant patients with DGF. Up to 204 adult kidney transplant recipients will be enrolled in this 2-part study.

"We are pleased with the FDA acceptance of our DGFi IND application for prevention of delayed graft function, which is a very serious medical issue for kidney transplant patients," said Shai Erlich, Ph.D., Chief Development Officer of Quark. "This is an important milestone for us. It marks Quark's third clinical program and the second in which our siRNA drug is administered systemically to patients. This achievement provides further validation of Quark's RNAi based drug discovery approach."

About DGF and Kidney Transplant

Delayed Graft Function (DGF) in renal transplantation is a syndrome caused by ischemia and reperfusion injury. Ischemia reperfusion injury occurs frequently in kidneys that have been outside a living human body and damaged from lack of oxygen in the kidneys that have been blood deprived. In patients with DGF the transplanted kidney does not function properly and requires intervention by dialysis.

Delayed graft function (DGF) is the most common complication during the immediate postoperative period in renal transplantation and affects 25-40% of the cadaveric renal transplants in the United States. In addition to donor, recipient, transplant procedure and the choice of immunosuppression may influence DGF development. Post kidney transplant DGF is associated with increased of length of hospital stay, and higher rate of graft rejection, resulting in decreased short and long-term survival. Currently when DGF is diagnosed, the main strategy is to support the patient with dialysis and to monitor for rejection with serial biopsies.

About DGFi

DGFi is an siRNA designed to temporarily inhibit the activity of the p53 gene that is based on Quark's proprietary, patented therapeutic of temporarily and reversibly inhibiting the expression of the transcription factor human p53, which is associated with DNA repair and apoptosis. The concept was first published by Quark with the University of Chicago in a breakthrough paper in Science magazine (Science. 1999 Sep 10; 285). Preclinical studies have shown that p53-targeted siRNA can be effective in protecting kidneys from injury due to cold ischemia or lack of oxygen during organ preservation and storage between removal from the donor and implantation. DGFi is a chemically modified siRNA with an AtuRNAi technology-based structure licensed from Silence Therapeutics and for which Quark has also licensed certain intellectual property from Alnylam.

About Quark Pharmaceuticals, Inc.

Quark Pharmaceuticals, Inc. is a development-stage pharmaceutical company engaged in discovering and developing novel therapeutic RNAi drug candidates. Quark has a fully integrated drug development platform that spans therapeutic target identification to drug development. Quark's RNAi technology includes novel siRNA structures and chemistry that the Company believes provide Quark with freedom to operate in the siRNA intellectual property arena, as well as the ability to deliver siRNA locally and systemically to organs including the eye, ear, kidney, lung, spinal cord and bone marrow.

Quark's lead product, PF-4523655 (RTP801i-14), completing Phase I/IIa clinical trials, is a synthetic, chemically modified, siRNA molecule to temporarily inhibit the expression of Quark's proprietary target gene RTP801. PF-4523655 is licensed to Pfizer on an exclusive worldwide basis. Quark expects its partner, Pfizer, to continue to progress PF-4523655 through Phase II clinical trials for the treatment of AMD and diabetic macular edema (DME). In addition, Quark's current clinical pipeline includes AKIi-5, developed by Quark for the prevention of acute kidney injury (AKI) following major cardiac surgery, currently in Phase I/IIa clinical trials via systemic delivery. Based on publicly available information, Quark believes this was the first siRNA delivered systemically in a human clinical trial. The Company has licenses for AtuRNAi(TM) technology from Silence Therapeutics and additional RNAi intellectual property from Alnylam.

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