Small interfering RNA (siRNA) has outstanding potential as a therapeutic agent.Several contributions to improvements in their tissue and cellular delivery has thus far been made with a variety of encapsulating structures, large terminal conjugates and cell surface receptor ligands.Sirnaomics is developing specific PNP systems for siRNA delivery, both locally and/or systemically.This PNP technology allows selection of the best approach to ensure efficient and safe delivery of siRNAs to their target tissues.Three generations of nanoparticle systems for siRNA delivery are being developed.Our first generation of delivery agents uses clinically viable nanoparticles.Biodegradable Histidine-Lysine copolymer (HKP) is the proprietary delivery system for our leading siRNA therapeutic candidate [STP705].It self-assembles with siRNA into nanoparticles having average size of 150 nM in diameter.In this presentation, we will show and discuss new data and results related to the CMC, formulation and animal toxicity profile of the STP-705 drug product.We will also show how that PNP can significantly enhance therapeutic activity of the siRNAs without compromising safety of patients.