Unaudited Preliminary Results 2011

21 March 2012

New Team members with Proven Track Record of building value For shareholders

– Anthony Sedgwick, Ph.D., Chief Executive Officer ( Biotech Entrepreneur Novacta, Daniolabs, Cambridge Biotechnology, Roche)

– George Büchner, Ph.D., Head of Business development

(Novacta, Haptogen, Pharma Ventures)

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2011 Highlights

– Positive interim data presented at ASCO – Data showed excellent safety and indications of potential efficacy

– Leadership position validated by three new partnerships

– Top 10 pharma company, InteRNA Technologies and miRNA Therapeutics – Further deal signed with miRagen Inc in January 2012

– Positive clinical results from partners

– Quark and Pfizer positive Phase II results in diabetic macular oedema – Organisation streamlined

– Californian facility was closed, Board membership reduced

– Enhanced commercial focus – New business development team recruited

– Intellectual property strengthened

– PKN3 patent issued in Japan, Zamore re-issued in US, Tuschl I clarified (Europe) – Fundraising of £5.51m (net of expenses) in May 2011

– To fund development of pipeline and investment in RNAi technology platform

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2011 Post year-end Highlights

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– Dr Tony Sedgwick was promoted to Chief Executive Officer

– Deal announced with miRagen Therapeutics for the delivery of microRNAs using the DBTC liver delivery systems

– Silence's second deal on DBTC and third for microRNAs

– Creation of a Scientific Advisory Board – Two Key Opinion Leaders in the area of liver disease –announced today

RNAi – James Watsons vision 2012

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An Overview of Silence Therapeutics

• European Biotechnology Company

• Listed on LSE (AIM) with operations centralised in Berlin

• Cutting Edge technology- RNAi (Ribose Nucleic acid Interference)

• Experienced New Management Tony Sedgwick CEO –Geo Buchner Business

Several value drivers:

• External Milestones and Royalties (Quark)

• Internal Phase I First in Class Cancer Therapy (To be completed mid-2012)

• Low cost preclinical Pipeline

• Strong IP (e.g. AtuRNAi, Licenses to Fire & Mello and Zamore Patents)

• One of only 2 companies with prosecuted patents in area

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What is RNAi

Transformative technology

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RNAi can “Silence” Undruggable problem genes

Stabilised AtuRNAi Naked can target All

Genes

Targets that can be blocked by small

molecule drugs or antibodies

22,000 genes

Human Genome At the origin of numerous

diseases The RNAi technology

can target ALL OF THEM

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Two value drivers: External and Internal

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Potential External revenue streams

Novartis

$3-11 million

Pfizer

$4 million

Pfizer/Quark

$85 million

Novartis/Quark

$71-77 million

2012 2014 Remaining milestones

Total milestone potential: approx $170 million

PLUS further potential milestone payments from the AstraZeneca collaborations

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siRNA technology trigger

Commercial landscape: Delivering the great promise of RNAi

Development of successful delivery

solutions

Delivery challenges Identified

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And Internal value drivers…

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Silences AtuRNAi plus Disease “bespoke” delivery system makes a drug

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Atu027: New Cancer treatment in Phase I

• Atu027 ‘silences’ the production of PKN3 a Key regulator of blood and lymph vessel formation

• Inhibition of PKN3 leads to: • reduced oxygen supply to

tumour

• reduced tumour growth/metastases

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Atu027 is RNAi against PKN3 plus Atuplex

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Atu027: successfully progressed to a phase I

Investment

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Atu027 is safe in man and could be a new medicine for treating difficult cancers

• Atu027 Phase I interim data demonstrates safety (ASCO 2011)

• 10 out of 27 patients showed stable disease after treatment period

• Atu027 very well tolerated - effective dose exceeded

• Phase I results expected to report in mid-2012

• Biomarker data currently under evaluation

• Looking for Co development partner

• Validates AtuPLEX™ delivery technology

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AtuRNAi plus DACC system makes a drug for treating lung Cancer and life threatening lung disease

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Silence´s DACC delivery system: targets siRNAs to the lungs

• Address lung-specific diseases e.g. acute lunG injury/ARDS/Cancer by delivering siRNA primarily to the lungs

• Single dose sufficient to inhibit target gene

• Expression in the lungs for up to a month

• Atu111 in preclinical

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AtuRNAi plus DBTC system makes a drug for treating liver Cancer and life threatening liver disease

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Silence´s DBTC: targets siRNAs to the liver

• Address liver-specific diseases e.g. HCC, ischemia reperfusion injury

• Single dose inhibits gene

expression in the liver for up to 1 week

• Well tolerated (up to 8.3 mg/kg) • Preclinical studies ongoing

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Silence’s Revenue Stream

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Two value drivers: External and Internal

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Silence Power………………….

• New Management with proven track record

• Cutting Edge technology

• First in Class RNAi new cancer therapy

• One of only two companies with Prosecuted patents in area

• Lean organisation

• Pipeline of drugs and deals

• Undervalued

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Results for 2011

GBP ‘000s 2011 unaudited

2010 audited

Revenue

R&D spend

Admin costs

Restructuring costs

Operating loss

Other income/(expense)

Loss after tax

694 2,366

(137)

Net cash 3,688 3,567

(8,795)

(8,658)

-

(5,203)

(5,821) (3,361)

49

(5,737)

(5,786)

(472)

(2,647)

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Newsflow 2012

Update on AstraZeneca collaboration

Sign delivery collaboration with miRagen

Start of Phase IIb trial of PF’-655 in DME (Quark/Pfizer)

Sign further collaboration agreements

Completion of enrolment in Atu027 trial

Start of Phase II trial of QPI-1002 in AKI (Quark/Novartis)

Publication of white paper on delivery technologies

Completion of Atu027 phase I trial

Completion of phase II trial of QPI-1002 delayed graft function

Start of phase Ib/II trial of Atu027

Further patent issuances

January 2012

January 2012

1Q 2012

1H 2012

1H 2012

1H 2012

1H 2012

Mid 2012

2H 2012

2H 2012

2H 2012

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Disclaimer

The statements made in this presentation may contain certain forward-looking comments. Actual

events or results may differ from the Company’s expectations. In addition to the matters described in

the presentation, future actions by the European Agency for Evaluation of Medicinal Products, the U.S. Food and Drug Administration or equivalent

regulatory authorities in other countries and results of pending or future clinical trials, as well as other

risk factors outlined from time to time in the Company’s regulatory filings, may affect actual

results achieved by the Company. The Alternative Investment Market (AIM) has not reviewed and does

not accept responsibility for the adequacy or accuracy of this presentation.

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Key peers

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