Director/PDMR Shareholding

1 Apr 2008 07:05

Silence Therapeutics plcDirector's Dealings

London, 1 April 2008 Silence Therapeutics plc (the Company) (AIM: SLN) announces that on Monday 31 March 2008, Peter Reynolds informed the Company that on this day he purchased 50,000 ordinary shares in the Company at 47.5 pence per share and 25,000 ordinary shares in the Company at 45 pence per share. Following these purchases of, in aggregate, 75,000 ordinary shares, Mr Reynolds has an interest in 347,408 ordinary shares in the Company, representing 0.29 per cent of the issued share capital of the Company.

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Silence Therapeutics plc Citigate Dewe Rogerson +44(0)20 7307 1620 +44(0)20 7638 9571 Jeff Vick, Chief Executive Officer David Dible Melvyn Davies, Finance Director Emma Palmer Nominated Advisers U.S. Contacts: Nomura Code Securities Limited LaVoie Group +44(0)20 7776 1200 +1 - 978.745.4200 Chris Collins Bryan Murphy ext 105 Gerard Harper Tim Allison ext 102 Notes to Editors

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

Silence Therapeutics plc (AIM: SLN) is a leading RNAi company. RNA interference (RNAi) can selectively 'silence' genes linked to the onset of disease.

Silence Therapeutics has developed novel, proprietary short interfering RNA ('siRNA') molecules, AtuRNAi, which provide a number of advantages over conventional siRNA molecules as they show increased stability against nuclease degradation. In addition, the Company has developed a proprietary systemic delivery system, AtuPLEX. This enables the delivery of siRNA molecules to targeted diseased tissues and cells, whilst increasing their bioavailability and intracellular uptake.

In July 2007, Silence Therapeutics formed a research and development collaboration with AstraZeneca to develop AtuRNAi against five specific targets including those in respiratory indications. In March 2008, the Company entered into a second collaboration with AstraZeneca to develop novel approaches to the delivery of siRNA molecules. The Company's AtuRNAi technology also has been sublicensed to Pfizer through Quark's license to Pfizer 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 its proprietary compound AKIi-5. This compound is in a Phase I human clinical study for treatment of acute kidney injury. In addition, Silence Therapeutics expects to begin the clinical development of its own proprietary AtuRNAi therapeutic molecules for systemic cancer indications in 2008.

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

About RNAi

RNA interference (RNAi), a Nobel Prize winning technology, is 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.