Cytomyx Holdings PLC
04 August 2005


For Immediate Release                                              4 August 2005



        Cytomyx further expands ion channel cell line capabilities with
                   a worldwide co-exclusive license agreement
                           with Wyeth Pharmaceuticals


Validated Ion Channel cell lines for Kv4.3 and the four KChIP accessory sub-unit
                    proteins are now available from Cytomyx


Cytomyx Ltd (Cambridge, UK), a division of Cytomyx Holdings, PLC (AIM:CYX.L), a
leading provider of drug discovery products and services, is pleased to announce
that it has signed a worldwide co-exclusive license agreement with Wyeth
Pharmaceuticals (PA, USA) which allows Cytomyx to create and market cell lines
expressing the ion channel, Kv4.3 , and the four KChIP accessory sub-units as
research reagents for use in drug discovery and safety pharmacology screening.
Wyeth  holds the patents and patent applications relating to the ion channels
Kv4.3, and the four KChIP accessory sub-units.

The validated cell lines can also be accessed via Cytomyx' unique IonScreenTM,
Ion Channel Screening Service.  The service combines Cytomyx' unparalleled range
of validated ion channel cell lines with its expertise in automated
electrophysiology to deliver timely, high quality data.



This strategically important agreement expands further the unique ion channel
cell line and screening service portfolio offered by Cytomyx to pharmaceutical
and biotechnology clients worldwide. Currently the company has 18 validated ion
channel cell lines available and 50 more are in development.  Cytomyx continues
to be the industry leader for ion channel related products and services and has
seven out of the top ten pharmaceutical companies as clients to date.



Kv4.3 and the four KChiP accessory sub-units are important targets for drug
discovery and safety pharmacology because they combine in different ways in
different tissues to make a significant contribution to regulating the
electrical activity of the brain and the heart.  This regulation can be
disturbed by diseases, is at the core of learning and memory and can be the
cause of the side effects of medicines.



In consideration of the license Wyeth Pharmaceuticals will access know-how and
validated cell lines from Cytomyx, enabling them to progress internal drug
screening and safety pharmacology programs.



                                     -Ends-


For Further Information Contact:

Cytomyx                                                 Tel: +44 (0) 1223 508191
6-7 Technopark, Cambridge, CB5 8PB, UK.                 Fax: +44 (0) 1223 508198

Mike Kerins, CEO,
Email: mike.kerins@cytomyx.com
Web: www.cytomyx.com

Wyeth Pharmaceuticals,                                  Tel: +1 484 865 8947
500 Arcola Road, Collegeville, PA, 19426, USA           Fax: +1 484 865 9301

Christine Foster, Senior Director, Licensing,
Email: fosterc1@wyeth.com
Web: www.Wyeth.com

Buchanan Communications                                 Tel: +44 (0)207 466 500
107 Cheapside, London EC2V 6DN                          Fax: +44 (0)207 466 5001

Mark Court, Director
Mary-Jane Johnson, Account Director







Note to Editors

About Cytomyx Holdings

Cytomyx Holdings plc is a rapidly growing life science company based in
Cambridge, UK. The Company's primary focus is on developing novel technologies
that assist pharmaceutical and biotechnology companies in their efforts to
develop new treatments more effectively. The company does this by providing
solutions that provide early insights into the likely efficacy and safety
profile of new drugs in development. The Company has two main areas of
expertise: the use of human clinical samples in understanding the linkage
between gene expression and disease and the development of cell-based assays
that are used to support ion channel drug discovery and predict potential
cardiac toxicity in new drugs.  Cytomyx is listed on the AIM market of the
London Stock Exchange (CYX.L). For more information visit
www.cytomyx-holdings.com






                      This information is provided by RNS
            The company news service from the London Stock Exchange
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