Notice of Interim Results

PRESS RELEASE

3rd September 2014

HORIZON DISCOVERY GROUP PLC

("Horizon" or "the Company")

Notice of Interim Results

Cambridge, UK, 3rd September 2014: Horizon Discovery Group plc (LSE: HZD) (Horizon), the international life science company supplying research tools to organizations engaged in genomics research and the development of personalized medicines, will announce interim results for the six months ended 30 June 2014, on Tuesday 23 September 2014.

Dr Darrin Disley, Chief Executive Officer, and Richard Vellacott, Chief Financial Officer, will host a presentation and live conference call for analysts at 10:00am on the morning of the results at the Dome Room, 1 Cornhill, London, EC3V 3ND.

ENDS

Notes to Editors

Contacts:

Consilium Strategic Communications (Financial Media and Investor Relations)

Amber Bielecka / Mary-Jane Elliott / Jessica Hodgson / Matthew Neal

[email protected]

Tel: +44 (0) 20 3709 5701

Zyme Communications (Trade and Regional Media)

Katie Odgaard

Email: [email protected]

Tel: +44 (0)7787 502 947

Panmure Gordon (UK) Limited (NOMAD)

Corporate Finance: Freddy Crossley / Duncan Monteith / Fred Walsh

Broking: Tom Salvesen

Tel: +44 20 7886 2500

About Horizon Discovery www.horizondiscovery.com/

Horizon is a revenue-generating life science company supplying research tools to organizations engaged in genomics research and the development of personalized medicines. Horizon has a diverse and international customer base approaching 1,000 organizations across nearly 50 countries, including major pharmaceutical, biotechnology and diagnostic companies as well as leading academic research centers. The Company supplies its products and services into multiple markets, estimated to total in excess of £29 billion by 2015.

Horizon's core capabilities are built around its proprietary translational genomics platform, GENESIS™, a high-precision and flexible suite of gene editing tools able to alter almost any endogenous gene sequence of human or mammalian cell-lines. Horizon offers almost 2,200 products, almost all of which are based on the application of GENESIS™ to generate cell lines that accurately model the disease-causing mutations found in genetically based diseases. These 'patients-in-a-test-tube' are being used by customers to identify the effect of individual or compound genetic mutations on drug activity, patient responsiveness, and resistance, which may lead to the successful prediction of which patient sub-groups will respond to currently available and future drug treatments.

In addition, Horizon provides GENASSIST™ CRISPR and rAAV gene editing tools, custom cell line generation services for research and bioproduction applications, quantitative molecular reference standards, contract research and custom screening services, custom shRNA development services and off-the-shelf validated shRNA (through Horizon's partner Sirion), and haploid cell lines (through Horizon's partner Haplogen). These latter partnerships provide Horizon with almost 11,000 further products for our customers.

Horizon is headquartered in Cambridge, UK, and is listed on the London Stock Exchange's AIM market under the ticker "HZD". For further information please visit: www.horizondiscovery.com.