Merger discussions

Merger discussions

London 29 September 2009 

The Directors of Silence Therapeutics plc (the "Company") note the recent press speculation and confirm that the Company is in merger discussions. The Company expects the proposed transaction to be treated as a reverse takeover under the AIM Rules. Accordingly, trading in the Company's shares has been suspended pending publication of an Admission document. The proposed transaction is subject to due diligence and would be conditional upon shareholder approval.
A further announcement will be made in due course.

- Ends -


For further information, please contact the following:

Silence Therapeutics plc   
+44(0)20 7307 1620   
Iain Ross, Chairman & CEO   
Melvyn Davies, Finance Director    
+44(0)20 7250 1446
Paul Durman
Kay Larsen

Nominated Advisers   
Nomura Code Securities Limited   
+44(0)20 7776 1200   
Chris Collins   
Jonathan Senior   

Notes to Editors:

About Silence Therapeutics plc (

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.

Silence's lead internal product, Atu027, is a proprietary AtuRNAi molecule in clinical development for systemic cancer indications.  Atu027 has successfully completed single and repeat dose toxicology and geno-toxicology studies, as well as a 28-day toxicology study using multiple dosing regimens.  In June 2009, the Company started 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
(LSE: AZN) 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 compound, 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.