Quark Pharmaceuticals Announces First Patient Dosing by Pfizer in Phase II Trial of RNAi Therapy in Diabetic Mac...( Clinical Program Leverages Quark'...),Health

Clinical Program Leverages Quark's RNAi Technology

FREMONT, Calif., July 30 /PRNewswire/ -- Quark Pharmaceuticals, Inc., a development-stage pharmaceutical company discovering and developing novel RNA interference (RNAi)-based therapeutics, today announced that its partner, Pfizer Inc, initiated patient dosing in a Phase II trial evaluating

PF-4523655 (RTP801i-14) in patients with diabetic macular edema (DME).

PF-4523655 is a novel siRNA drug candidate being co-developed by Quark and Pfizer. As part of the companies' Global Licensing Agreement, the successful commencement of the trial triggers a milestone payment to Quark from Pfizer, a small percentage of which is payable by Quark to Silence Therapeutics and Alnylam as technology license milestone payments.

The Phase II prospective, randomized, dose-ranging study is evaluating the safety and efficacy of PF-4523655 versus laser therapy in 160 DME patients at multiple centers worldwide. PF-4523655 was designed to inhibit Quark's proprietary target RTP801, a gene involved in abnormal blood vessel development and leakage in the eye. Under the companies' Global Licensing Agreement, Pfizer has exclusive development rights to siRNA-mediated therapies that inhibit RTP801 for ophthalmic and non-ophthalmic indications, while Quark is eligible for development and sales based milestone payments.

Elena Feinstein, Chief Scientific Officer of Quark, commented, "By targeting the RTP801 gene, PF-4523655 is differentiated from other therapeutics for the same ophthalmic indications. While many competitors target VEGF and its receptors, PF-4523655 inhibits abnormal blood vessel growth and leakage independently of the VEGF pathway, reduces inflammation and suppresses apoptosis. Therefore,

PF-4523655 is a siRNA therapeutic candidate with the potential to be efficacious when used as a monotherapy and in combination with existing VEGF-based therapies."

Shai Erlich, Chief Development
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