Intradigm Corporation, a leading developer of targeted, systemic RNA interference (RNAi) therapeutics, has got US patent (application 10/859,337) from United States Patent and Trademark Office (USPTO) which generally claims methods of enhancing the RNA silencing activity of an RNAi agent in a mammalian or plant cell.

The allowed subject matter is not only focused on claims to siRNAs but also includes specific coverage for micro RNAs (miRNAs), miRNA precursors, primary miRNA transcripts and short hairpin RNA (shRNA). The allowed application, based on the seminal research by Philip Zamore, Ph.D., is one of several applications disclosing certain efficacy-enhancing structural elements of RNAis that Intradigm exclusively licensed from the University of Massachusetts Medical School.

Strengthened by recent strategic IP licensing deals with both the University of Massachusetts Medical School and the Massachusetts Institute of Technology (MIT), Intradigm possesses one of the industry's strongest RNAi IP positions. Intradigm's IP estate of issued patents broadly covers structural features for a next generation of RNAi molecules, biodegradable polycationic polymers for the delivery of RNAi therapeutics, and proprietary siRNA sequence applications.

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.