Notice of Results

PRESS RELEASE

7 April 2016

HORIZON DISCOVERY GROUP PLC

("Horizon" or "the Company")

Notice of Preliminary Results

Cambridge, UK, 7 April 2016: Horizon Discovery Group plc (LSE: HZD) (Horizon), the leading international gene editing company, announces today that its preliminary results for the twelve months ended 31 December 2015 will be announced on Tuesday 26 April 2016.

Dr Darrin Disley, Chief Executive Officer, and Richard Vellacott, Chief Financial Officer, will host a presentation and live conference call for analysts at 9.30am on the morning of the results in the Dome Room at 1 Cornhill, London, EC3V 3ND.

ENDS

Notes to Editors

For further information, please contact:

Horizon Discovery Group plc

Dr. Darrin Disley CEO/ Richard Vellacott CFO

Tel: +44 (0) 1223 655580

Consilium Strategic Communications (Financial Media and Investor Relations)

Amber Fennell / Jessica Hodgson / Matthew Neal / Laura Thornton

Tel: +44 (0) 20 3709 5701

Email: [email protected]

Panmure Gordon (UK) Limited (NOMAD)

Corporate Finance: Freddy Crossley / Fabien Holler / Duncan Monteith

Corporate Broking: Tom Salvesen

Tel: +44 20 7886 2500

Zyme Communications (Trade and Regional Media)

Katie Odgaard

Tel: +44 (0)7787 502 947

Email: [email protected]

About Horizon Discovery Group plc www.horizondiscovery.com/

Horizon is a leading international gene-editing company that supplies products, services and research programmes that enable genomics research and the development of personalised and genomic medicines. Horizon has a diverse and global customer base of over 1,400 unique organisations across more than 50 countries, including major pharmaceutical, biotechnology and diagnostic companies as well as leading academic research centres. The Group supplies its products and services into multiple markets, estimated to total in excess of £29 billion in 2015.

Horizon's core capabilities are built around its proprietary translational genomics platform, a highly precise and flexible suite of gene editing tools (rAAV, ZFN and CRISPR) able to alter almost any gene sequence in human or mammalian cell-lines.

Horizon offers over 23,000 catalogue products, almost all of which are based on the application of gene editing to generate in vitro and in-vivo models that accurately model the disease-causing genetic anomalies found in diseases like cancer. These 'patients-in-a-test-tube' are being used by customers to: understand the genetic drivers of disease; identify targets of therapeutic intervention that can moderate or correct these genetic drivers; develop novel medicines and companion diagnostic tests that result in the right patient getting the right medicine.

Horizon also provides custom in vitro and in vivo disease model generation services, biopharmaceutical manufacturing cell lines and generation services, quantitative molecular reference standards and contract research and custom screening services.

In addition, Horizon through its Research Biotech business deploys the Company's intellectual property, gene-editing platform, products, services and know-how in cancer research, drug discovery and immunology to develop its immuno-oncology, synthetic lethality and cell therapy platforms which aim to deliver novel drug treatments into the pharmaceutical pipeline.

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.