Quark Pharmaceuticals Presented At Arvo Data Showing That Pf-04523655 Enters Retinal Cells And Elici

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11th May 2009, 12:19pm - Views: 897

Quark Pharmaceuticals Presented At ARVO Data Showing That PF-04523655 Enters

Retinal Cells And Elicits Its Pharmacologic Effect Via Target Gene Knock-Down Without

Activating TLR3

FREMONT, Calif., May 11 /PRNewswire-AsiaNet/ --

    Quark Pharmaceuticals, Inc., a development-stage pharmaceutical company discovering and

developing novel RNA interference (RNAi)-based therapeutics, today announced that Elena

Feinstein, M.D., Ph.D., Chief Scientific Officer, presented a study titled, “PF-04523655

(REDD14NP), an siRNA Compound Targeting RTP801, Penetrates Retinal Cells Producing

Target Gene Knockdown and Avoiding TLR3 Activation,” at the Association for Research in

Vision and Ophthalmology (ARVO) Annual Meeting, taking place from May 3-7, 2009, in Fort

Lauderdale, Florida. PF-04523655 is currently being studied by partners Pfizer and Quark in

patients with diabetic macular edema (DME) and age-related macular degeneration (AMD).

    The study presented at ARVO was performed in collaboration with Dr. Jayakrishna Ambati at

the Department of Ophthalmology and Visual Sciences, University of Kentucky College of

Medicine, Lexington, KY. The objective of the study was to determine whether PF-04523655, a

synthetic chemically modified 19-bp siRNA, enters cells in the retina leading to downregulation

of its target gene while avoiding activation of Toll Like Receptor 3 (TLR3). Previous studies from

Dr. Ambati’s laboratory have shown that unmodified 21-mer siRNA molecules exhibit

antiangiogenic effects by inadvertently activating TLR3 rather than down-regulating expression

of their target genes. Results obtained in vivo and in vitro indicated that PF-04523655 does

enter cells in the retina and elicits its pharmacologic effect via target gene knock-down without

activating TLR3.

    Daniel Zurr, Ph.D., President and Chief Executive Officer, said, "We believe that the results

presented at ARVO continue to substantiate our leadership in siRNA therapeutics, in particular

Quark’s ability to develop highly specific siRNA products and advance them through the clinic

toward commercialization. Quark’s ability to establish collaborations with major pharmaceutical

companies like Pfizer to co-develop PF-04523655 in DME, wet-AMD, and other potential ocular

indications provides further credibility to our siRNA technology capabilities."

    Jayakrishna Ambati M.D., Professor and Vice Chair, Department of Ophthalmology & Visual

Sciences, University of Kentucky, member of Quark’s Medical Advisory Board, and one of the

authors on the study, stated, "My laboratory’s research has shown that many siRNAs suppress

neovascularization regardless of their sequences or targets and can have dangerous off target

effects. For that reason, I’m gratified to see this research, suggesting that Quark is seeing

success in developing siRNA compounds that are effective."

    About Quark Pharmaceuticals, Inc.

    Quark Pharmaceuticals, Inc. is a development-stage pharmaceutical company engaged in

discovering and developing novel RNAi-based therapeutics. 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 providing Quark with freedom

to operate in the siRNA intellectual property arena, as well as the ability for non-invasive

delivery of siRNA to other target tissues including the eye, ear, lung, spinal cord and brain.

Science Research Quark Pharmaceuticals, Inc. 2 image

    PF-04523655 (RTP801i-14), currently in Phase II clinical trials, is a synthetic, chemically

modified siRNA designed to inhibit the expression of the gene RTP801 discovered by Quark

through the gene discovery platform BiFAR. PF-04523655 is licensed to Pfizer. In addition,

Quark’s current clinical pipeline includes QPI-1002, the first systemically administered siRNA

drug in human clinical trials, developed by Quark for the prevention of acute kidney injury (AKI)

following major cardiac surgery and of delayed graft function in kidney transplantation. For the

structure of these products Quark has licenses from Silence Therapeutics and from Alnylam


    QPI-1007, a siRNA that utilizes a proprietary structure developed by Quark, is being

evaluated in advanced IND-enabling preclinical studies as a neuroprotective agent for eye

diseases. In addition, Quark has a broad pipeline of siRNA drug candidates based on novel

structures developed internally. The Company expects to utilize the structures to develop

additional RNAi drug candidates.

    Quark is headquartered in Fremont, California and operates research and development

facilities in Boulder, Colorado and Ness-Ziona, Israel. Additional information is available at

    Quark Pharmaceuticals, Inc.        The Ruth Group (investors / media)

    Juliana Friedmann                  Sara Ephraim / Janine McCargo

    +972 89 30 5111                    (646) 536-7004 / 7033

    jfriedman@quarkpharma.com          sephraim@theruthgroup.com


SOURCE: Quark Pharmaceuticals, Inc.

    CONTACT: Juliana Friedmann of Quark Pharmaceuticals, Inc., 




             or Investors, 

             Sara Ephraim, 



             or Media, 

             Janine McCargo, 



             both of The Ruth Group


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