SLN.L Regulatory News (SLN)

13 Mar 2008 14:15

Silence Therapeutics and AstraZeneca Announce Collaboration to Develop Novel Approaches for siRNA Drug Delivery

London, 13 March 2008 - Silence Therapeutics plc (AIM:SLN) today announces a collaboration with AstraZeneca , focused on the development of a range of novel approaches for the delivery of siRNA molecules. The deal builds on Silence Therapeutics' leading expertise in the delivery of siRNA molecules, in particular its success with the functional systemic delivery of siRNA in vivo using its proprietary AtuPLEX technology. The financial details of this collaboration, in which both parties will contribute expertise and know-how, have not been disclosed.

This new deal is independent of the parties' three-year collaboration signed in July 2007, whose aim is to develop novel siRNA therapeutics against specific targets exclusive to AstraZeneca.

As a result of today's agreement, Silence Therapeutics and AstraZeneca will work together to develop new and improved approaches for the delivery of siRNA molecules. The successful delivery of siRNA molecules to different tissue sites is critical to realize the exciting potential of siRNA to treat a broad range of diseases. Under the terms of the agreement both Silence Therapeutics and AstraZeneca will be allowed to commercialise the truly novel delivery systems that they develop together.

Jeff Vick, CEO of Silence Therapeutics, commenting on today's announcement said, "We are delighted to enter this new collaboration with AstraZeneca for the development of novel approaches for the delivery of siRNA molecules. This agreement highlights the significant progress we have made with our AtuPLEX platform, following our early realization of the importance of delivery to the development of successful RNAi therapeutics. This deal also reflects the strong working relationship we have developed with AstraZeneca and the progress of our ongoing collaboration in the development of AtuRNAi molecules against a number of their targets."

Mr. Vick continued, "We look forward to continuing our work with AstraZeneca in this important therapeutic area, and are extremely excited about the potential of our AtuPLEX delivery technology today and its ability to be developed further so that it can become an even more significant value driver for Silence Therapeutics."

Silence Therapeutics will retain the right to sign further `delivery' deals to capture value from its current AtuPLEX delivery technology as well as any improvements to this technology that it generates either independently or as part of this collaboration.

Claude Bertrand, Global VP, Discovery Respiratory & Inflammation, at AstraZeneca said "We are very happy with the working relationship we have developed with the team at Silence Therapeutics and the progress made over the last six months via our agreement to develop siRNA therapeutics against a number of our targets. Today's announcement is designed to generate the novel delivery approaches that are needed if this exciting class of novel drugs is to realize fully its potential. Based on Silence Therapeutics' significant current expertise in siRNA delivery we are confident that we have found a strong partner to achieve our ambitions in this area."

- Ends -

Enquiries:

For further information, please contact the following:

Silence Therapeutics plc European Contacts: +44(0)20 7307 1620 Citigate Dewe Rogerson Jeff Vick, Chief Executive Officer +44(0)20 7638 9571 Melvyn Davies, Finance Director & Company David Dible

Secretary Heather Keohane Nominated Advisers: U.S. Contacts:

Nomura Code Securities Limited LaVoie Group

+44(0)20 7776 1200 +1 - 978.745.4200 Chris Collins Bryan Murphy x 105 Gerard Harper Tim Allison x 102 AstraZeneca Contact Details Media Enquiries: Investor Relations:

Steve Brown +44 (0) 207 304 5033 Jonathan Hunt +44 (0) 207 304 5087 Frances Sutcliffe +44 (0) 1625 514 120 Karl Hard +44 (0) 207 304 5322

JĦrgen Winroth +1 (212) 579 0506 Ed Seage +1 302 886 4065 Notes to Editors

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

Silence Therapeutics plc is a leading RNAi company. RNA interference (RNAi) can selectively 'silence' genes linked to the onset of disease.

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

In July 2007, Silence Therapeutics formed a research and development collaboration with AstraZeneca to develop AtuRNAi against five specific targets including those in respiratory indications. The Company's AtuRNAi technology also has been sublicensed to Pfizer through Quark's license to Pfizer of the compound RTP-801i-14 for the treatment of Age-related Macular Degeneration (AMD) and a number of other indications. This compound entered the clinic in early 2007. Silence Therapeutics also has licensed to Quark rights to the AtuRNAi structure for its proprietary compound AKIi-5. This compound is in a Phase I human clinical study for treatment of acute kidney injury. In addition, Silence Therapeutics expects to begin the clinical development of its own proprietary AtuRNAi therapeutic molecules for systemic cancer indications in 2008.

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

About AstraZeneca

AstraZeneca is a major international healthcare business engaged in the research, development, manufacture and marketing of prescription pharmaceuticals and the supply of healthcare services. It is one of the world's leading pharmaceutical companies with healthcare sales of $29.55 billion and leading positions in sales of gastrointestinal, cardiovascular, neuroscience, respiratory, oncology and infection products. AstraZeneca is listed in the Dow Jones Sustainability Index (Global) as well as the FTSE4Good Index.

For more information about AstraZeneca please visit: www.astrazeneca.com

About RNAi

RNA interference (RNAi), a Nobel Prize winning technology, is one of the most exciting areas of drug discovery today. This is because 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.