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Quark Says New siRNAs Offer IP Freedom



Quark Pharmaceuticals announced it has developed proprietary siRNA structures that it claims will enable it to develop drug candidates based entirely on its own intellectual property. The company has, however, disclosed few details about the molecules.

"We no longer need to rely on other people's patents as far as the structure of the siRNA," says Quark CEO Danny Zurr. Patent applications covering the structures are completely owned by Quark and "we have ascertained through two independent … IP law firms that, indeed, we have the freedom to operate.

"We looked at all the issued patents, and more importantly, all the patent applications that have been published," he says, adding that Quark's new siRNAs are "totally outside" of existing IP in the field, including the Tuschl-1, Tuschl-2, Kreutzer-Limmer, and Crooke patents, which are primarily controlled by Alnylam Pharmaceuticals.

Besides professing their IP edge, Zurr says he expects the new structures to enable Quark to forge technology-licensing deals, which could prove to be a sorely needed source of cash in a down market.

Zurr remains tight-lipped on the specific details about the siRNAs, stating that more information will be made available once the relevant patent applications are published. He does note, however, that the various siRNAs that the company develops based on the new technology will each incorporate different structural modifications based on their targets.

"There is no such thing as … a generic structure," he says. "You have to have a number of different structures tailor-made to the actual [target] sequence. [Ours] is a family of several structures that we can use as a basis to look for the best structure" for a particular sequence.

Importantly, Zurr says, this family of structures does not trigger any immune responses, such as the activation of Toll-like receptors, which has become a key hurdle facing RNAi-based drug makers.

Doug Macron

RNAi Notes

Rosetta Genomics is assessing its microRNA-based miRview Squamous diagnostic with Johns Hopkins University School of Medicine. The diagnostic is supposed to differentiate squamous from non-squamous non-small cell lung cancer.

ZaBeCor has formed a subsidiary, called Biothorpe Pharmaceuticals, to develop siRNAs, antisense compounds, and other molecular technologies as cancer treatments. ZaBeCor will continue to focus on inflammatory disorders.

Calando Pharmaceuticals' next siRNA-based cancer drug, called CALAA-02, is in pre-clinical development. The compound is supposed to target hypoxia-inducible factor-2 alpha, which is over-expressed in many solid tumors and is needed for tumor growth.


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Funded Grants

$99,960/FY 2008
Developing Adjuvant SiRNA Therapy for Huntington's Disease
Grantee: Peng Li, Eragene Pharmaceuticals
Began: Sep. 15, 2008; Ends: Aug. 31, 2009
With this grant, Peng Li will be developing an RNAi enhancer to raise siRNA efficacy while lowering the RNAi dose needed and prolonging the silencing effect. In particular, Li will be trying to silence the genes that encode the huntingtin protein involved in Huntington's disease. The team will determine what the RNAi-enhancing compound concentration needs to be to target Htt in an in vitro system and see if using RNAi-E is feasible.

$437,294/FY 2008
Cancer targeted therapy through bacterial RNAi
Grantee: Chiang Jia Li, Boston Biomedical
Began: Jul. 10, 2008; Ends Jun. 30, 2009
Chiang Jia Li will be working on developing an RNAi-based therapy for colon cancer. He hypothesizes that non-pathogenic bacteria can both make and deliver RNAi and would bypass host interferon-like responses. He will first determine in vitro if bacterial RNAi does circumvent inferno-like response and then will see if this system can deliver shRNAs to solid murine colon tumors in vivo.

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