$750,000 contract win from top ten pharma

PRESS RELEASE

17th November 2014

Horizon Discovery Group Signs Agreement with Top Ten Pharma Company for Approximately $750,000

Horizon CombinatoRx to perform drug combination screening on a lead oncology asset

Cambridge, UK, 17th November 2014: Horizon Discovery Group plc (LSE:HZD) (Horizon), a leading provider of research tools to support translational genomics and the development of personalized medicines, today announced that its Horizon CombinatoRx division has been contracted by a top ten pharma company to profile a lead oncology asset. Under the terms of the agreement, Horizon CombinatoRx will be paid approximately USD $750,000 (GBP £469,000) for work to be completed within a five month period.

Horizon CombinatoRx provides its partners access to the unique cHTS platform and Chalice™ analytics software, which enable the screening and analysis of thousands of complementary drug combinations. Combined with Horizon's GENESIS™ (rAAV, CRISPR and ZFN) gene editing platform and X-MAN™ isogenic cell line technology, Horizon CombinatoRx offers services including novel phenotypic cell-based screens with compound siRNA, shRNA and sgRNA (for CRISPR based screening) libraries.

Horizon completed the acquisition of the CombinatoRx service business and assets from Zalicus Inc. in June 2014.

Dr Darrin M Disley, Chief Executive Officer of Horizon Discovery Group plc, commented: "We are delighted that Horizon CombinatoRx continues to gain the traction in the market we expected following the acquisition earlier this year. This latest contract with a top ten pharma in the oncology space continues to demonstrate the value Horizon CombinatoRx can offer to support key drug discovery and development programs in cancer."

ENDS

Notes to Editors

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

Consilium Strategic Communications (Financial Media and Investor Relations)

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

Tel: +44 (0) 20 3709 5701

Email: [email protected]

Zyme Communications (Trade and Regional Media)

Katie Odgaard

Tel: +44 (0)7787 502 947

Email: [email protected]

Panmure Gordon (UK) Limited (NOMAD)

Corporate Finance: Freddy Crossley / Duncan Monteith / Fred Walsh

Broking: Tom Salvesen

Tel: +44 20 7886 2500

About Horizon Discovery Group plc 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, in vivo disease models, 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.