Notice of Interim Results

HORIZON DISCOVERY GROUP PLC

("Horizon" or "the Company")

Notice of Interim Results

Cambridge, UK, 7 September 2016: Horizon Discovery Group plc (LSE: HZD) ("Horizon"), the world leader in the application of gene editing technologies, announces today that its interim results for the six months ended 30 June 2016 will be announced on Tuesday 20 September 2016.

Dr Darrin Disley, Chief Executive Officer, and Richard Vellacott, Chief Financial Officer, will host a presentation and live conference call for analysts at 9.00am on the morning of the results in the Guildhall Room, 85 Gresham Street, London, EC2R 7HE. A recording of the call will be made available on the Company website later in the day.

For further information, please contact:

Consilium Strategic Communications (Financial Media and Investor Relations)

Mary-Jane Elliott / Sue Stuart / Matthew Neal / Melissa Gardiner

Tel: +44 (0) 20 3709 5701

Email: [email protected]

Numis Securities Limited (Joint Broker and NOMAD)

Michael Meade / Freddie Barnfield

Tel: +44 (0) 207 260 1000

RBC Capital Markets (Joint Broker)

Paul Tomasic / Marcus Jackson

Tel: +44 (0) 20 7653 4000

About Horizon Discovery Group plc www.horizondiscovery.com/

Horizon Discovery Group plc (LSE: HZD) ("Horizon"), is a world-leading gene editing company that designs and engineers genetically-modified cells and then applies them in research and clinical applications that advance human health.

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 and related research services, almost all of which are based on the generation and application of cell and animal models that accurately recapitulate the disease-causing genetic anomalies found in diseases like cancer. Horizon's commercial offering has been adopted by c1,400 unique research organisations in over 50 countries as well as in the Company's own R&D pipeline to support: a greater understanding of the genetic drivers of disease and the development of molecular, cell and gene therapies that can be prescribed on a personalised basis.

Horizon is headquartered in Cambridge, UK, and is listed on the London Stock Exchange's AIM market under the ticker "HZD".