SILENCE THERAPEUTICS PLC - Appointment of finance director

London, October 12

London, 15 October 2012 - Silence Therapeutics plc has appointed Tim Freeborn, 53, as its finance director. A chartered accountant, he joined the company from Xcap Securities where he was head of research.

Tim Freeborn said: `Silence's area of biotech is moving incredibly quickly. The company could play a big role and I'm delighted to be joining at this time.'

No further disclosures are required under Rule 17 and Schedule 2(g) of the AIM Rules.

Silence Therapeutics                                                           
                                                                               
Ali Mortazavi (+44 7768 694739 /Tim                                            
Freeborn (+44 20 7491 6520)                                                    
                                                                               
Email:                                                                         
a.mortazavi@silence-therapeutics.com                                           
                                                                               
t.freeborn@silence-therapeutics.com                                            

                                                                               
Singer Capital Markets                  M:Communications                       
                                                                               
Shaun Dobson/Jenny Wyllie               Mary-Jane Elliot / Sarah MacLeod /     
                                                                               
+44 20 32057500                         Claire Dickinson                       
                                                                               

shaun.dobson@nplus1singer.com           +44 20 7920 2342                       
                                                                               
jenny.wyllie@nplus1singer.com           silencetherapeutics@mcomgroup.com      

Notes for editors

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

Silence Therapeutics plc (AIM: SLN) is a leading biotechnology company dedicated to the discovery, development and delivery of targeted, systemic RNA interference (RNAi) therapeutics for the treatment of serious diseases. Silence offers one of the most comprehensive short interfering RNA (siRNA) therapeutic platforms available today based on a strong intellectual property portfolio and large clinical safety database. Silence's clinical siRNA product pipeline is one of the broadest in the industry. The Company possesses multiple proprietary siRNA delivery technology platforms including AtuPLEX™, DACC and DBTC. AtuPLEX enables the broad functional delivery of siRNA molecules to targeted diseased tissues and cells, while increasing their bioavailability and intracellular uptake. The DACC delivery system allows functional delivery of siRNA molecules selectively to the lung endothelium with a long duration of target mRNA and protein knock-down. The DBTC delivery system enables functional delivery of siRNA molecules selectively to liver cells including hepatocytes. Additionally, the Company has a platform of novel siRNA molecules based around its AtuRNAi chemical modification technology, which provides a number of advantages over conventional siRNA molecules. Silence's unique RNAi assets also include structural features for RNAi molecules and specific design rules for increased potency and reduced off-target effects of siRNA sequences.