Mercia EIS Funds

PolyTherics and MacroGenics extend Collaboration to Produce Novel Antibody Drug Conjugates

ThioBridge™ linker to attach different payloads to a range of antibodies

London, UK, 11 April 2014 – PolyTherics Limited (“PolyTherics”), a provider of technologies and services to enable the development of better biopharmaceuticals, today announced an extension to its ThioBridge™ antibody drug conjugate (“ADC”) collaboration with MacroGenics Inc (NASDAQ: MGNX), a US biotechnology company developing innovative medicines utilizing its next generation antibody technologies.

PolyTherics has developed ThioBridge™ for site-specific conjugation of cytotoxic payloads to antibodies to provide more stable and less heterogeneous ADCs. MacroGenics has two antibody technology platforms, a Dual-Affinity Re-Targeting (DART™) bi-specific platform, in which a single recombinant molecule is able to target two different antigens, and Fc-optimized antibodies with improved effector function.

The collaboration was extended following the successful outcome of a research programme undertaken in 2013 under a Research Collaboration and Option Agreement, in which ThioBridge™ was used to conjugate a cytotoxic payload to a range of DART antibodies. MacroGenics and PolyTherics will collaborate in the application of its ThioBridge™ technology to a number of product candidates derived from MacroGenics’ antibody platforms. MacroGenics has an option to licence the ThioBridge™ technology for the development of these product candidates and PolyTherics would receive development milestones and a single-digit percentage royalty on sales of any ThioBridge™ ADC derived from this collaboration.

John Burt, CEO of PolyTherics, commented “We are pleased with the success of our initial work with MacroGenics’ antibodies and their extension of the collaboration to a wider range of antibodies and payloads endorses their support for the versatility of ThioBridge™ and its use to produce better ADCs.”

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About PolyTherics

PolyTherics provides technology solutions to enable the development of better biopharmaceuticals and offers a portfolio of proprietary and complementary technologies and services to address key needs in biopharmaceutical development.

PolyTherics’ portfolio of services and technologies includes proprietary site-specific conjugation technologies and novel polymers for optimising the therapeutic properties of biopharmaceuticals and through its Cambridge, UK-based subsidiary, Antitope, services for protein immunogenicity assessment and antibody and protein re-engineering technologies are delivered. The group provides its services and technologies to an international client base that includes most of the world’s leading biotechnology and pharmaceutical companies.

PolyTherics is a privately owned UK company backed by institutional investors including Imperial Innovations (AIM: IVO), Invesco Perpetual, Mercia Fund Management, Advantage Enterprise & Innovation Fund (managed by Catapult Venture Partners), ProVen Health, Oxford Technology VCTs and high net worth individuals’ funds managed by Longbow Capital. The Company has dedicated facilities in London, Cambridge and Coventry, UK.

www.polytherics.com

For more information please contact:
PolyTherics
John Burt, PolyTherics
Tel.: +44 (0)20 7691 3580
Email: john.burt@polytherics.com
Mark Swallow, Sita Shah, Chris Gardner
Citigate Dewe Rogerson
Tel.: +44 (0)20 7282 2948/1052/2995
Email: mark.swallow@citigatedr.co.uk