Horizon Discovery : Capital Markets Day Date Change to 5 March 2018

Horizon Discovery Group plc

Capital Markets Day Date Change to 5 March 2018

Cambridge, UK, 20 February 2018: Horizon Discovery Group plc (LSE: HZD) ('Horizon' or 'the Group'), a global leader in gene editing and gene modulation technologies, announces that as a result of the leadership changes announced separately today, the Capital Markets Day in London for investors and sell-side analysts, will now take place on 5 March 2018 at Etc. Venues Fenchurch Street, 43/44 Crutched Friars, London, EC3N 2HH starting at 13:00 GMT / 8:00 EDT.

There will be a simultaneous live conference call and webcast for those unable to attend in person. The webcast, with the presentation slides, will be available athttps://www.horizondiscovery.com/about-us/investor-relationsand a recording will be made available shortly thereafter.

Please contacthorizon@consilium-comms.comif you would like to attend.

ENDS

For further information from Horizon Discovery Group plc, please contact:

Horizon Discovery Group plc

Ian Gilham, Chairman

Richard Vellacott, Interim Chief Executive Officer

Tel: +44 (0) 1223 655 580

Numis Securities Limited (Broker and NOMAD)

Michael Meade / Freddie Barnfield

Tel: +44 (0) 207 260 1000

Consilium Strategic Communications (Financial Media and Investor Relations)

Mary-Jane Elliott / Matthew Neal / Melissa Gardiner

Tel: +44 (0) 20 3709 5701

Email: horizon@consilium-comms.com

About Horizon Discovery Group plcwww.horizondiscovery.com

Horizon Discovery Group plc (LSE: HZD) ('Horizon') is a world leader in gene editing and gene modulation technologies. Horizon designs and engineers cells using its translational genomics platform, a highly precise and flexible suite of DNA editing tools (rAAV, ZFN, CRISPR and Transposon) and, following the acquisition of Dharmacon, Inc., its functional genomics platform comprising gene knockdown (RNAi) and gene expression (cDNA, ORF) tools, for research and clinical applications that advance human health. Horizon's platforms and capabilities enable researchers to alter almost any gene or modulate its function in human or mammalian cell-lines.

Horizon offers an extensive range of catalogue productsand related research services to support a greater understanding of the function of genes across all species and the genetic drivers of human disease and the development of personalised molecular, cell and gene therapies. These have been adopted by over 10,000 academic, drug discovery, drug manufacturing and clinical diagnostics customers around the globe, as well as in the Company's own R&D pipeline.

Horizon is headquartered in Cambridge, UK, and is listed on the London Stock Exchange's AIM market under the tic