Last updated on April 16, 2014 at 12:50 EDT

Appointment of Finance Director

October 15, 2012

LONDON, October 15, 2012 /PRNewswire/ –

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

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.

Notes for editors

About Silence Therapeutics plc (http://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(TM),
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

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 AtuPLEX(TM).

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.

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

        Singer Capital Markets
        Shaun Dobson/Jenny Wyllie

        Mary-Jane Elliot / Sarah MacLeod /
        Claire Dickinson

SOURCE Silence Therapeutics Plc

Source: PR Newswire