Silence Obtains Important Patent Protection for Lead Internal Development Compound,...

Silence Obtains Important Patent Protection for Lead Internal Development
Compound, Atu027
European Patent Office Notifies Company of Intent to Grant Patent

LONDON, July 23 /PRNewswire/ -- Silence Therapeutics plc
(AIM: SLN), a leading European RNAi focused biotechnology company, today
announces new intellectual property cover for its lead product, Atu027. The
European Patent Office announced on July 17, 2008 that it intends to grant a
European patent covering Silence's lead internal product candidate. This
patent will give Silence broad exclusivity not only for Atu027, but for any
siRNA targeting protein kinase N beta.
The notice is based on European patent application EP 03 790 894.4. The
claims deemed allowable by the European Patent Office are directed to various
aspects of the use of protein kinase N beta, the gene target of Atu027. Among
others, the claims are related to any siRNA molecule, including Atu027,
directed against protein kinase N beta for use in the treatment of numerous
cancers involving the PI3-kinase pathway. Other claims are related to the use
of protein kinase N beta for screening purposes and its use as a downstream
target of the PI3-kinase pathway.
Atu027 is a proprietary AtuRNAi molecule currently in development for
solid cancer indications, including gastrointestinal and lung cancers. The
candidate is designed to silence the function of a novel kinase protein
involved in tumour growth and metastases and utilizes Silence Therapeutics's
proprietary drug delivery system AtuPLEX to deliver active drug into the
appropriate cells following systemic administration.
"The protection of targets through composition of matter patents is an
important part of our patent strategy," said Iain Ross, Chairman and CEO of
Silence Therapeutics. "The notice of intent to grant represents a significant
step forward for the Group in both its own programs and those of its
collaborators, as it provides intellectual property cover not only for the
Company's lead product, Atu027, but also broad exclusivity for any siRNA
targeting protein kinase N beta."
Notes to Editors:
About Silence Therapeutics plc (www.silence-therapeutics.com)
Silence Therapeutics plc (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 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.
SOURCE Silence Therapeutics plc

Iain Ross, Chairman & Chief Executive Officer, Melvyn Davies, Finance
Director, Silence Therapeutics plc, +44(0)20-7307-1620; European Contacts,
David Dible, or Heather Keohane of Citigate Dewe Rogerson, +44(0)20-7638-9571;
Thomas Christely, Chief Executive Officer, or Klaus Giese, Chief Scientific
Officer, Silence Therapeutics AG, +49(0)30-9489-2800; for Nominated Advisers:
Chris Collins, Nomura Code Securities Limited, +44(0)20-7776-1200; for U.S.
Contacts: Tim Allison, +1-978-745-4200 x 102, or Lisa Rivero, +1-978-745-4200
x 106, both of LaVoie Group, for Silence Therapeutics plc