Appointment of Chief Business Officer

21 Sep 2011 07:00

FOR IMMEDIATE RELEASE

Appointment of Chief Business Officer

London, September 21, 2011 -Silence Therapeutics plc (AIM: SLN) ("Silence", the "Group" or the "Company"), a leading global RNA interference (RNAi) therapeutics company, today announces the appointment of Tony Sedgwick PhD, FRCPath as Chief Business Officer with immediate effect. Dr Sedgwick will be based in Silence's London office and lead the growing Business Development team within Silence.

Tony Sedgwick is an experienced biotechnology and pharmaceutical entrepreneur with extensive experience in small and large company transactions and will assume responsibility for the broadening of Silence's partnerships. He was most recently Chief Executive Officer of the UK biotech company Novacta and Chairman of the Norwegian biotech company Plastid AS. Previously Tony was Chief Executive Officer of the UK biotech company Daniolabs Ltd. and the UK biotech company Cambridge Biotechnology Ltd., both companies being successfully exited by trade sale. Tony has been an executive and non-executive of a large number of life science companies in the UK and continental Europe. Between 1986 and 2002 Tony worked for Roche in several senior management roles, latterly as Global Head of Clinical Operations and UK Development Director.

Commenting on the appointment, Thomas Christ©ly, Chief Executive Officer of Silence,said: "We welcome Tony to the Silence team and look forward to taking advantage of his vast experience of the global pharmaceutical industry as we seek to broaden our collaborations with global pharmaceutical and biotechnology companies.Tony will be responsible for enlarging our business development team, as we seek to substantially increase our resourcesa nd efforts in this area. Generating non-dilutive cash is a key corporate goal for Silence, and Tony and his team will focus on identifying and securing partnerships and collaborations for our clinical and pre-clinical portfolio. I look forward to working closely with Tony in the exciting months ahead."

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For further information, please contact:

Silence Therapeutics Singer Capital Markets Thomas Christ©ly - CEO Shaun Dobson/Claes Sp¥ng Max Herrmann - CFO +44 20 32057500 +44 20 7491 6520 shaun.dobson@singercm.com m.herrmann@silence-therapeutics.com claes.spang@singercm.com Vida Communication (US) M:Communications (Europe) Tim Brons (media)/Stephanie Diaz Peter Laing / Emma Thompson (investors) +44 20 7920 2345 / +44 20 7920 2342 +1 (415) 675-7400 healthcare@mcomgroup.com tbrons@vidacommunication.com sdiaz@vidacommunication.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 AtuPLEXâ„¢ and DACC. 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. 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.

The Company's lead internal drug candidate is Atu027, a liposomal formulation in clinical development for systemic cancer indications and one of the most clinically advanced RNAi therapeutic candidates in the area of oncology. Atu027 incorporates two of the Company's technologies, AtuRNAi and AtuPLEXâ„¢. Silence is currently conducting an open-label, single-centre, dose-escalation Phase I study with Atu027 in patients with advanced solid tumors involving single, as well as repeated, intravenous administration. Encouraging interim data were presented at the American Society of Clinical Oncology Annual Meeting in June 2011. The study is expected to be completed in H1 2012.

The Company's RNAi therapeutic platform has received key validation through multiple partnerships with pharmaceutical companies including AstraZeneca, Dainippon Sumitomo, Pfizer/Quark, and Novartis/Quark. Silence is actively pursuing the establishment of additional partnerships. Silence Therapeutics has operations in both Berlin and London.

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