Issue of Options

ISSUE OF OPTIONS

26 June 2013

Issue of share options

The Company announces that on 26 June 2013 the Remuneration Committee has granted conditional share options to directors and staff totalling 1,486,378 under the Silence Therapeutics Employees' Share Option Scheme 2013 which was approved for adoption by the Board of the Company on 17 June 2013. The share options will vest after three years and are exercisable at 125p per share subject to a 400p hurdle rate, being twice the placing price of the £19m placing in April 2013.

Grants to directors are as follows:

Following the issue of these options the total number of options is 4,768,984, equal to c.10% of the Company's issued share capital. Of this c.10%, 6.3% were granted as part of the rescue refinancing in August 2012.

In recognition of work in the April refinancing, the board has decided to vest 1,008,045 options awarded to Ali Mortazavi in 2012 and 190,000 awarded to Tim Freeborn. Exercise dates for these options are unchanged.

For further information please contact:

Silence Therapeutics

Ali Mortazavi, chief executive/Timothy Freeborn, finance director +44 (0)333 988 0140

[email protected]

[email protected]

N+1 Singer

Shaun Dobson/Jenny Wyllie

+44 20 7496 3000

[email protected]

[email protected]