SLN.L Regulatory News (SLN)

27 Aug 2009 07:00

Silence Therapeutics signs siRNA delivery collaboration with

Dainippon Sumitomo Pharma

London - 27 August, 2009 - Silence Therapeutics plc (AIM: SLN), the leading European biopharmaceutical company focused on RNA interference (RNAi), today announced that it has entered into a delivery collaboration with Dainippon Sumitomo Pharma Co., Ltd. of Japan to demonstrate the functional delivery of Silence's proprietary siRNA molecules to specific targets.

Silence Therapeutics has developed AtuRNAi, a novel proprietary short interfering RNA (siRNA) molecule which is chemically modified to improve stability, reduce manufacturing costs and increase yield. The collaboration will also make use of Silence's AtuPLEX delivery technology, which has been shown to improve functional intracellular uptake.

Iain Ross, chairman and chief executive of Silence Therapeutics, said:

"We are delighted to have signed this agreement with Dainippon Sumitomo Pharma, which further underscores the potential of Silence's science and delivery technology. We anticipate that the initial collaboration will lead to a substantive relationship between our companies."

Dr. Keiichi Ono, senior executive officer and executive director of drug research division of Dainippon Sumitomo Pharma, said:

"Following extensive due diligence in the sector, we have chosen to partner with Silence Therapeutics because of the company's proven ability in the delivery of siRNA molecules and the depth of its experience in this area. We look forward to expanding this collaboration further in the future."

Financial details have not been disclosed.

Silence Therapeutics has been advised by Summit Pharmaceuticals International which represents and markets the technologies, products and expertise of Silence Therapeutics in Japan.

- Ends -

Enquiries:

For further information, please contact the following:

Silence Therapeutics plc Powerscourt 44 (0) 20 7491 6520 +44 (0) 20 7250 1446 Iain Ross, Chairman & CEO Paul Durman Thomas Christely, COO Kay Larsen Nominated Advisers Nomura Code Securities Limited +44 (0) 20 7776 1200 Richard Potts Notes to editors

About Silence Therapeutics plc (www.silence-therapeutics.com)

Silence Therapeutics plc (AIM: SLN) is a leading European RNAi-focused biotechnology company.

RNA interference (RNAi), is a Nobel Prize winning technology and one of the most exciting areas of drug discovery today. It represents a completely new approach to selectively 'silence' or inactivate disease relevant genes and as such it has the potential to create a new class of therapeutic products. RNAi could therefore offer a therapeutic approach to a broad range of diseases (cancer, infectious diseases, inherited diseases), many of which have been regarded as incurable and are not addressed by current therapeutics, therefore providing a large market opportunity.

Silence Therapeutics has developed a platform of novel short interfering RNA ('siRNA') molecules, AtuRNAi, which provide a number of advantages over conventional siRNA molecules, including increased stability against nuclease degradation. In addition, the Company has developed a proprietary systemic delivery system, AtuPLEX. This system enables the functional delivery of siRNA molecules to targeted diseased tissues and cells, while increasing their bioavailability and intracellular uptake.

Following the granting of its patents in Europe, the USA and Australia, Silence Therapeutics is one of only two companies worldwide with a proprietary position on composition of matter for siRNA therapeutics.

The Company has started in June 2009 an open-label, single-centre, dose-escalation Phase I study with Atu027 in patients with advanced solid (malignant) tumours involving single as well as repeated intravenous administration. Atu027 specifically targets PKN3, a molecule involved in cancer growth and metastasis formation. Atu027 is Silence's most advanced clinical candidate for a systemically delivered short interfering RNA (siRNA) using the Company's proprietary AtuPLEX delivery technology.

In March 2008 Silence Therapeutics announced a collaboration with AstraZeneca focused on the development of a range of novel delivery approaches for siRNA molecules. Under the terms of the agreement both Silence Therapeutics and AstraZeneca will be allowed to commercialize the truly novel delivery systems that the two partners develop together.

Silence Therapeutics has granted a licence to AstraZeneca to develop novel AtuRNAi therapeutics against five specific targets. This collaboration was the first industry validation of the potential application of Silence Therapeutics' proprietary AtuRNAi molecules and solidified the Company's leadership position in field of RNAi therapeutics.

The Company's AtuRNAi technology also has been sublicensed to Pfizer via Quark's license to them of the compound RTP-801i-14 for the treatment of age-related macular degeneration (AMD) and a number of other indications. This compound entered a phase II clinical study in July 2008. Silence Therapeutics also has licensed to Quark rights to the AtuRNAi structure for Quark's proprietary compounds, AKIi-5 and DGFi, which are both in Phase I human clinical studies for treatment of acute kidney injury and delayed graft function in kidney transplantation, respectively.

Forward-Looking Statements

This press release includes forward-looking statements that are subject to risks, uncertainties and other factors. These risks and uncertainties could cause actual results to differ materially from those referred to in the forward-looking statements. All forward-looking statements are based on information currently available to Silence Therapeutics and Silence Therapeutics assumes no obligation to update any such forward-looking statements.

Silence Therapeutics is based in London, UK, and Berlin, Germany, and is listed on AIM.

About Dainippon Sumitomo Pharma (www.ds-pharma.co.jp/english)

Dainippon Sumitomo Pharma Co., Ltd. is a top-ten listed pharmaceutical company in Japan with a diverse portfolio of pharmaceutical, animal health and food and specialty products. The company's strong research and development presence in the areas of CNS, diabetes, cardiovascular disease, and inflammation/allergy, is based on the merger in 2005 between Dainippon Pharmaceutical Co., Ltd., and Sumitomo Pharmaceuticals Co., Ltd.