Silence Therapeutics plc, a leading RNA interference (RNAi) therapeutics company, announces that it has entered into an agreement with one of the world’s leading global pharmaceutical companies to investigate the application of Silence’s proprietary DACC delivery technology for intravenous delivery of short interfering RNA sequences (“siRNAs”) to the pulmonary vascular endothelium.

Under the terms of the agreement, Silence’s partner will provide Silence with specific siRNAs, which Silence will formulate with its DACC delivery system. Silence and its partner will undertake in vitro and in vivo studies of the DACC formulated siRNAs developed under  the agreement and select lead candidates for further evaluation. Financial terms were not disclosed.

DACC is a novel lipid delivery system that includes Silence’s proprietary lipid AtuFect and is  used to embed siRNAs into a multiple lipid bi-layer structure. Whilst closely related to the AtuPLEX delivery system used in  Atu027, Silence’s lead oncology candidate in phase I trials, DACC has significantly different properties on a physiochemical and pharmacological  level. The DACC delivery system is incorporated in Atu111, Silence’s preclinical development candidate for the treatment of acute lung injury, and enables functional, highly specific and efficient delivery of RNAi therapeutics to the pulmonary vascular endothelium. In preclinical models, the DACC delivery system has demonstrated  highly focused delivery to lung tissue and sustained knockdown of the desired target gene expression in this particular cell type. Of note, the DACC delivery system has shown sustained protein knock-down of over three weeks.

Thomas Christély, chief executive officer of Silence Therapeutics, said: “We are delighted to be collaborating with another of the world’s largest pharmaceutical companies for the use of our delivery systems to deliver their selected  siRNAs. As we have stated, Silence is now significantly increasing its resource in  business  development, and we are delighted to be announcing another partnership. We believe that Silence’s proprietary DACC delivery system offers the potential to selectively deliver siRNAs and other oligonucleotides to pulmonary vascular endothelium, and we look forward to working closely with  our partner on this project.  Functional delivery into target cells is one of the greatest challenges facing most nucleic acid therapies and Silence remains committed to the development of its DACC and its other  proprietary  delivery systems, including AtuPLEX and DBTC, as it seeks to overcome these challenges.”