The paper, entitled "Potent siRNA Inhibitors of Ribonucleotide Reductase Subunit RRM2 Reduce Cell Proliferation In vitro and In vivo", was published in Clinical Cancer Research, a journal published by the American Association of Cancer Research (AACR). This paper describes how Calando's proprietary siRNA duplex demonstrated silencing of the target gene, RRM2, and reduced cell proliferation across multiple species and cancer types, both in cell culture and in whole animals. These findings confirm that this duplex is a promising candidate for therapeutic development.
"The paper reports some of the great progress being made at Calando," said R. Bruce Stewart, Chairman and CEO of Arrowhead. "We believe that siRNA will be one of the corner stones of cancer treatment in the future".
"These studies demonstrate the potential for this siRNA duplex to have a strong anti-tumor effect," said John Petrovich, Calando's Chief Executive Officer. He further added that Calando has filed for patent protection on several siRNA duplexes against the RRM2 target and has licensed patents from Alnylam Pharmaceuticals to enable it to develop and commercialize an RNAi therapeutic against this target.
Further information about Calando can be found at www.calandopharma.com.
About Arrowhead Research Corporation
Arrowhead Research Corporation (www.arrowheadresearch.com) is a publicly-traded nanotechnology company commercializing new technologies in the areas of life sciences, electronics, and energy. Arrowhead is building value for shareholders through the progress of ma jority owned subsidiaries founded on nanotechnologies originally developed at universities. The company works closely with universities to source early stage deals and to generate rights to intellectual property covering promising new nanotechnologies. Currently, Arrowhead has four subsidiaries commercializing nanotech products and applications, including anti-cancer drugs, RNAi therapeutics, carbon-based electronics and compound semiconductor materials.
About Calando Pharmaceuticals Inc.
Calando Pharmaceuticals Inc. (www.calandopharma.com), a majority owned subsidiary of Arrowhead Research Corporation (NASDAQ: ARWR), is using its proprietary technologies in targeted polymeric delivery systems and siRNA design to design and create new, targeted siRNA therapeutics. The company is pursuing this goal through its internal research and development and also through collaborations and partnerships with pharmaceutical and biotechnology companies.
Calando's cyclodextrin-containing polymers form the foundation for its two-part siRNA delivery system. The first component is a linear, cyclodextrin-containing polycation that, when mixed with small interfering RNA (siRNA), binds to the anionic "backbone" of the siRNA. The polymer and siRNA self-assemble into nanoparticles of approximately 50-80 nm in diameter that fully protect the siRNA from nuclease degradation in serum. The siRNA delivery system has been designed to allow for intravenous injection. Upon delivery to the target cell, the targeting ligand binds to membrane receptors on the cell surface and the RNA-containing nanoparticle is taken into the cell by endocytosis. There, chemistry built into the polymer functions to unpackage the siRNA from the delivery vehicle. In addition to targeting tumors, the targeting of liver cells has also been accomplished in vivo.
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