Board Change

Horizon Discovery Group plc

Board Change

Cambridge, UK, 2 March 2018: Horizon Discovery Group plc (LSE: HZD) ("Horizon" or "the Group"), a global leader in gene editing and gene modulation technologies, announces that, further to the statement issued on 20 February 2018 in which it was noted that Darrin Disley had decided to step down as CEO, Darrin Disley is no longer a Board Director of the Group as of today's date.

Horizon's Board consists of the following representatives:

Dr Ian Gilham

Executive Chairman

Richard Vellacott

Interim Chief Executive Officer and Chief Financial Officer

Dr Jonathan Milner

Non-Executive Director

Mrs Susan Searle

Non-Executive Director

Dr Susan Galbraith

Non-Executive Director

Dr Vishal Gulati

Non-Executive Director

Grahame Cook

Non-Executive Director

ENDS

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

Horizon Discovery Group plc

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: [email protected]

About Horizon Discovery Group plc www.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 products and 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 ticker "HZD".