Organizational Changes at Silence Therapeutics

LONDON, July 17 /PRNewswire/ --

    Silence Therapeutics plc (London AIM: SLN), a leading European RNAi
focused biotechnology company, announces that for personal reasons,
Jeffery Vick has resigned as Group CEO and left the Company.


    The Board of Directors has appointed Iain Ross, currently Non-Executive
Chairman, full time Chairman and Group CEO with immediate effect. Jeremy
Curnock Cook, a Non-Executive Director of the Company has been appointed
Senior Independent Non-Executive Director.


LONDON, July 17 /PRNewswire/ --

    On behalf of the Board of Silence Therapeutics plc, Jeremy Curnock Cook
said:


    "Iain Ross was responsible for the financial and operational turnaround
of the Company from July 2004 until July 2007, and the Silence Board of
Directors is confident that under his executive leadership, significant
shareholder value can be generated. Iain is an experienced business
negotiator and we believe he can bring to fruition a number of deals and
collaborations currently under discussion."


LONDON, July 17 /PRNewswire/ --

Iain Ross, Chairman & CEO added:

    "I believe that by employing a more focused and aggressive approach,
and with the continued support of a first class management team, we can
achieve meaningful technical and commercial milestones over the next 12
months. 


    We have a unique proprietary position in the RNAi space and I am
confident that this will be further strengthened in the coming months and
will be the basis upon which investors and pharmaceutical partners alike
will take an increasing interest in this Company. 


    Through current licensing agreements, products based upon the Company's
AtuRNAi technology are in the clinic and we plan to submit a regulatory
filing before the end of 2008 to commence clinical trials for our lead
internal development compound Atu027. I intend to commence partnering
discussions, following the interest that has been expressed by a number of
third parties in this development program."



Notes to Editors:

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

    Silence Therapeutics plc (London AIM: SLN) is a leading European RNAi
focused biotechnology company.  RNAi can selectively 'silence' genes linked
to the onset of disease.  RNAi is a Nobel Prize winning technology and one
of the most promising areas of drug discovery and development today.


    Silence Therapeutics has developed 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. In addition, the Company has developed a proprietary
systemic delivery system, AtuPLEX. This system enables the functional
delivery of siRNA molecules to targeted diseased tissues and cells, while
increasing their bioavailability and intracellular uptake.


    Silence's lead internal product, Atu027, is a proprietary AtuRNAi
molecule in preclinical development for systemic cancer indications. 
Atu027 has successfully completed single and repeat dose toxicology and
geno-toxicology studies, as well as a 28-day toxicology study using multiple
dosing regimens. Silence plans a regulatory filing in 2008 to commence
clinical trials for Atu027.


    In March 2008, Silence Therapeutics announced a collaboration with
AstraZeneca (LSE: AZN) focused on the development of a range of novel
delivery approaches for siRNA molecules.  Under the terms of the agreement
both Silence Therapeutics and AstraZeneca will be allowed to commercialize
the truly novel delivery systems that the two partners develop together.


    In July 2007, Silence Therapeutics formed its first research and
development collaboration with AstraZeneca to develop novel AtuRNAi
therapeutics against five specific targets, including those in respiratory
indications.  This collaboration was the first industry validation of the
potential application of Silence Therapeutics' proprietary AtuRNAi
molecules and solidified the Company's leadership position in the field
of RNAi therapeutics.


    The Company's AtuRNAi technology also has been sublicensed to Pfizer via
Quark's license to them of the compound RTP-801i-14 for the treatment of
age-related macular degeneration (AMD) and a number of other indications.
This compound entered the clinic in early 2007.  Silence Therapeutics also
has licensed to Quark rights to the AtuRNAi structure for Quark's proprietary
compound, AKIi-5, which is in a Phase I human clinical study for treatment of
acute kidney injury.


    Silence Therapeutics is based in London, UK, and Berlin, Germany, and is
listed on AIM.



About RNAi

    RNA interference (RNAi), is a Nobel Prize winning technology and one of
the most exciting areas of drug discovery today.  It represents a completely
new approach to selectively 'silence' or inactivate disease relevant genes
and as such it has the potential to create a new class of therapeutic
products.  RNAi could therefore offer a therapeutic approach to a broad range
of diseases (cancer, infectious diseases, inherited diseases), many of which
have been regarded as incurable and are not addressed by current therapeutics,
therefore providing a large market opportunity.



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.



Web site:  http://www.silence-therapeutics.com