Exercise of warrants

London, 08 March 2013

Silence Therapeutics plc ("Silence" or the "Company")

Exercise of warrants

The Company announces that it has received notice from ISM Capital to exercise warrants over 1,750,000 ordinary shares of 0.1p each at an exercise price of 1 pence per Ordinary Share. Accordingly, the Company will issue, in aggregate, 1,750,000 Ordinary Shares in settlement of this exercise. ISM has no warrants remaining following exercise.

The new Ordinary Shares will rank pari passu with the existing Ordinary Shares and application will be made for the new Ordinary Shares to be admitted to trading on AIM ("Admission"). It is expected that Admission will become effective and dealings in the new Ordinary Shares will commence at 8.00 a.m. on 14 March 2013.

Following the Warrant Exercise, the Company's issued share capital will consist of 0.1p  1,875,052,737 Ordinary Shares with voting rights. This number may be used by shareholders as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change to their interest in, the share capital of the Company.

Silence Therapeutics

Tim Freeborn, finance director +44 20 7491 6520

 [email protected]

N+1 Singer

Shaun Dobson/Jenny Wyllie

+44 20 74963000

[email protected]

[email protected]