Silence Therapeutics plc Notification of Results

LONDON, April 28, 2010 - Silence Therapeutics plc (AIM: SLN) ("Silence" or the "Company")
announces that it will be releasing its preliminary results for the year
ended 31 December 2009 on Thursday, 29 April 2010.

Analyst Conference Call and Webcast: An analyst briefing call and
simultaneous webcast will be held Thursday, 29 April 2010 at 2:00pm BST /
9:00am ET. The webcast can be accessed via Silence Therapeutics' website at
www.silence-therapeutics.com. The conference call can be accessed by
dialing:

    U.K.: 0-808-101-7548

    U.S.: +1-913-312-1483

    Participant PIN code: 6504213

The archived webcast will be available afterwards on Silence
Therapeutics' website.

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
activities in Berlin and operations in 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, CEO of Silence Therapeutics plc, +1-650-855-1514, p.haworth at silence-therapeutics.com, or Richard Potts / Jonathan Senior of Nomura Code Securities, +44-020-7776-1200, or media, Tim Brons of Vida Communication, +1-415-675-7400, tbrons at vidacommunication.com, or Investors, Stephanie Diaz, +1-415-675-7400, sdiaz at vidacommunication.com, both for Silence Therapeutics plc