Heptares Therapeutics Grants Shire an Exclusive Option to License Novel Adenosine A2A Antagonist

Best-in-Class Candidate With Potential in Treatment of CNS Diseases

WELWYN GARDEN CITY, England, May 9, 2011 - Heptares Therapeutics today announced it has signed an exclusive option
agreement with Shire Pharmaceuticals for a novel adenosine A2A antagonist
discovered by Heptares and currently in preclinical development. Adenosine
A2A is a G-protein coupled receptor (GPCR) involved in the regulation of
dopaminergic pathways in the brain. Recently, inhibition of the A2A receptor
has been proved to be clinically effective in treating symptoms of
Parkinson's disease and may offer benefits in additional CNS diseases.

The Heptares A2A programme reflects a new approach to this GPCR target.
Heptares stabilised the A2A receptor using its proprietary StaR(R)
technology, determined the receptor's binding characteristics through
Biophysical Mapping(TM), and resolved its 3D crystal structure using x-ray
crystallography. This advanced knowledge of the target enabled Heptares
scientists to discover entirely new types of chemical structures for
inhibiting the A2A receptor.

Under the terms of the agreement, Heptares has granted Shire an exclusive
option, upon completion of certain preclinical studies, to license worldwide
development and commercial rights to the Heptares A2A programme. Heptares has
received an upfront payment and is eligible, upon exercise of the option by
Shire, to an option exercise payment, future milestone payments, plus
royalties on product sales. Further terms of the agreement are not being
disclosed.

"We are excited to sign this option agreement with Shire for the
development of our novel A2A antagonist, a potentially best-in-class new
agent for treating patients suffering from debilitating CNS diseases," said
Malcolm Weir, CEO of Heptares. "A2A is an important and clinically validated
GPCR drug target, yet it has never been adequately addressed by the available
older chemistries. Heptares has discovered fundamentally novel chemotypes as
the basis for a new and, we believe, superior approach to A2A receptor
pharmacology."

About Heptares Therapeutics

Heptares is a drug discovery company creating new medicines targeting
G-protein-coupled receptors (GPCRs). The Company is currently leveraging its
GPCR expertise and proprietary StaR(R) technology to build a pipeline of
best-in-class and first-in-class GPCR-targeted medicines for the treatment of
CNS, metabolic and other diseases.

GPCRs represent the single most important family of drug targets in the
human body, yet, due to their inherent instability when removed from cell
membranes, little or no structural information about these valuable targets
has been available to drive structure-based drug discovery programmes.
Heptares' StaR(R) (Stabilised Receptor) technology enables the first-ever
thermo-stabilisation of GPCRs. This breakthrough allows Heptares scientists
to resolve GPCR structures and deploy structure-based drug discovery
techniques to identify potent and selective drug candidates to previously
undruggable targets.

Heptares has raised more than $40 million from leading venture investors,
Clarus Ventures, MVM Life Science Partners, Novartis Option Fund and Takeda
Ventures, and has formed partnerships with Shire, Takeda and Novartis.

For additional information, please visit: www.heptares.com

For information on Shire, please visit the Company's website:
www.shire.com

    Contact Information

    Heptares Therapeutics Ltd         +44-(0)1707-358-629
    Dr Malcolm Weir, CEO              malcolm.weir@heptares.com
    Dr Barry Kenny, CBO               barry.kenny@heptares.com

    Citigate Dewe Rogerson            +44(0)20-7282-2948
    Dr Mark Swallow, Dr Chris Gardner mark.swallow@citigatedr.co.uk

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