Silence Therapeutics Appoints Max Herrmann as Chief Financial Officer

Appointment Adds Key Financial and Fundraising Experience

LONDON, April 15, 2010 - Silence Therapeutics plc (AIM: SLN) ("Silence" or the "Company")
announces the appointment of Max Herrmann as the Company's chief financial
officer and company secretary with effect from May 4, 2010. Mr. Herrmann, 44,
possesses more than 20 years of biotechnology and pharmaceutical industry
experience having held key management positions with leading development
stage companies, as well as several investment banks. In his industry and
investment banking roles, he has been involved in the raising of more than
US$300M for biotechnology companies in the United States and Europe.

Most recently Mr. Herrmann served as chief financial officer of
Intercytex Group plc, a publicly traded company focused on the emerging area
of regenerative medicine. Before joining Intercytex, he spent over ten years
as a sell-side equity analyst, most recently as managing director and head of
European pharmaceutical and biotechnology research at ING. Prior to his
successful career in the City, Mr. Herrmann worked in the United States as
financial controller for Onyx Pharmaceuticals Inc., where he was involved in
the company's successful initial public offering on NASDAQ. He currently
serves on the board of directors of Regenerative Medicine Assets Limited, as
well as the company's subsidiaries Intercytex Ltd and Axordia Ltd.

Mr. Herrmann qualified as a Chartered Accountant with Arthur Andersen in
1993. He holds a degree in microbiology from the University of Kent.

"We are pleased to add an individual with Max's successful track record
to the Silence team and expect that his range of operational and financial
experience will greatly contribute to the long-term success of the Company,"
stated Philip Haworth, Ph.D., chief executive officer of Silence
Therapeutics. "We are confident this expertise will serve the Company well as
we continue to develop Silence's comprehensive RNAi therapeutics platforms."

"It is clear from the number of recent deals in the RNAi area that the
biopharmaceutical industry is recognizing the potential of this technology. I
am looking forward to joining one of the leading players in this field,"
commented Mr. Herrmann.

There are no other disclosures required under Schedule Two paragraph (g)
of the AIM Rules for Companies.

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

Silence Therapeutics plc (AIM: SLN) is a leading global biotechnology
company dedicated to the discovery, development and delivery of targeted,
systemic RNA interference (RNAi) therapeutics for the treatment of serious
diseases. The company possesses multiple proprietary siRNA delivery
technology platforms including AtuPLEX(TM), a system that enables the
functional delivery of siRNA molecules to targeted diseased tissues and
cells, while increasing their bioavailability and intracellular uptake. A
second, complementary delivery technology known as PolyTran(TM) uses a
library of novel peptide-based biodegradable polycationic polymers for
systemic siRNA administration. Additionally, the company has 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. Silence's unique RNAi assets also
include structural features for a next generation of RNAi molecules and
additional proprietary siRNA sequences against more than 50 highly valued
oncology and other disease targets.

The company's strong and diverse intellectual property portfolio includes
exclusive licenses from the University of Massachusetts on three patent
families associated with the Zamore "Design Rules," which cover broad
structural features of siRNA design for more potent next generation siRNA
sequences.

Silence Therapeutics is headquartered in London, UK, with research and
development operations in Berlin and Palo Alto, CA.

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.

Phil Haworth of Silence Therapeutics, +1-650-855-1514, p.haworth at silence-therapeutics.com; or Richard Potts or Jonathan Senior, both of Nomura Code Securities for Silence Therapeutics, +44(0)020-7776-1200; or media, Tim Brons, tbrons at vidacommunication.com, or investors, Stephanie Diaz, sdiaz at vidacommunication.com, both of Vida Communication for Silence Therapeutics, +1-415-675-7400