Study Shows Intradigm’s RNAi Nanoplex Technology to be Effective Systemic siRNA Delivery Platform for the Treatment of Various Cancer Models

Intradigm Corporation, a leading developer of targeted, systemic RNA interference (RNAi) therapeutics, today announced study results that demonstrated the company’s RNAi Nanoplex (NPX) delivery technology platform is capable of effectively delivering small interfering RNAs (siRNAs) targeting both vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) pathways, two clinically validated pathways in the treatment of various cancers. Study data demonstrated that mice treated with Intradigm’s proprietary peptide-based, biodegradable polymer (PolyTran™) carrying each of VEGF-, VEGFR2- or EGFR-targeted siRNAs experienced significant tumor growth inhibition that was similar to that of mice receiving the study’s positive control (VEGF antibody Bevacizumab or EGFR tyrosine kinase inhibitor Erlotinib). In addition, mice in the active siRNA treatment groups demonstrated no apparent toxicity or significant weight loss.

These study findings, which also confirmed the gene-silencing mechanism of action of Intradigm’s technology, were presented by Intradigm scientists on Sunday, April 13 at the 2008 American Association for Cancer Research (AACR) Annual Meeting in San Diego.

“We are very pleased with these study results as they confirm the gene-silencing mechanism of our RNAi NPX delivery technology, as well as its ability to systemically deliver siRNAs to tumors in a safe and effective manner,” said Mohammad Azab, M.D., president and chief executive officer of Intradigm. “Furthermore, by effectively targeting VEGF, VEGFR2, and EGFR, three established oncology targets, with our siRNAs, we have demonstrated the versatility of the RNAi NPX delivery technology which could be translated into multiple product opportunities for Intradigm’s pipeline of RNAi therapeutics.”

The findings presented today support data from several other in vivo models, including xenograft models of different cancers, which have demonstrated the efficacy of the RNAi NPX delivery technology.

ABOUT THE RNAi NANOPLEX DELIVERY TECHNOLOGY

To address the issue of effective and targeted delivery of RNAi therapeutics, Intradigm has developed and in-licensed an extensive intellectual property portfolio around its proprietary RNAi Nanoplex (NPX) delivery technology. The RNAi NPX delivery technology is a modular, multi-component delivery vector that carries active siRNA molecules in its core with the flexibility to attach a Polyethylene Glycol (PEG) layer and/or a targeting ligand to the polymer-siRNA NPX to improve circulation half life and achieve selective distribution to the target tissue. At the core of the RNAi NPX delivery technology is Intradigm’s proprietary peptide-based biodegradable polymer known as PolyTran™. PolyTran enables safe systemic delivery of the siRNAs. Additionally, this platform is unique in its ability to offer tissue specific targeting of siRNA through the attachment of specific ligands directed to target cell receptors. An additional key strength of the RNAi NPX delivery technology is its ability to incorporate multiple siRNAs in a single drug product. These multi-targeted therapeutics can simultaneously silence several mRNAs that represent parallel or synergistic elements of the same disease pathway resulting in a more comprehensive and/or novel therapeutic potential.

Recent technology licensing agreements with institutions such as the University of Massachusetts Medical School and the Massachusetts Institute of Technology have enhanced Intradigm’s existing intellectual property portfolio and provided the company with the rights and know-how to leverage a broad family of polymers and polymer structures, as well as next generation siRNA structures, in connection with its RNAi NPX delivery technology.