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Pharmaceutical Safety Testing Open Letter

Cyprotex PLC
("Cyprotex" or the "Company" or the "Group")

Concerns About Pharmaceutical Safety Testing Cause Cyprotex to Join in Signing an Open Letter to Prime Minister David Cameron and Health Secretary Andrew Lansley

On behalf of Cyprotex PLC (AIM:CRX), Dr. Katya Tsaioun, Cyprotex's Chief Scientific Officer, has joined with a group of eminent UK clinicians and scientists who have written an open letter to Prime Minister David Cameron and Health Secretary Andrew Lansley expressing concerns about the escalating problems of drug failures and adverse drug reactions. Adverse drug reactions have reached epidemic proportions amid rising costs in prescriptions, with around 197,000 EU citizens dying every year because of the problem.

The letter, published 3 June 2011 in the medical journal, The Lancet, says the reliance on testing new drugs on animals before humans is partly to blame, with trials on non-humans frequently failing to translate to the clinic. The experts have called for the use of more human-biology-based experiments where chemicals are tested on human cells to see how people might be affected by new treatments.

Following publication of the letter, Cyprotex's CEO, Dr. Tony Baxter, was interviewed by Sky News (see ) at Cyprotex's laboratory in Macclesfield.

Pointing at the crux of the problem, Dr. Baxter said, 'A fundamental problem is that a rat is not a human. They are different sizes, have different metabolisms, and have different diets. So using animals to predict effects on humans is difficult. Fifty percent of compounds that prove to be safe in rats prove not to be safe in humans. So it really is the toss of a coin.'

Remarking on the issue, Dr Katya Tsaioun said, 'In the past few years there has been tremendous progress in developing drug safety tests based on human biology. Many of these models, such as Cyprotex's CellCiphr™ assay for liver toxicity, are now superior to animal testing. Yet, the pharmaceutical industry is hesitant to adopt these tests because regulatory agencies have yet to adopt them, which is in turn caused by the agencies' failure to investigate them. The open letter addresses this by calling for the UK Government to initiate a comparison of a set of human-biology-based tests with those currently used, as proposed in the Safety of Medicines Bill 2010-11, to see which are more effective for predicting the safety of medicines for patients. 148 Members of Parliament have already signed a motion in support of this proposal.

'Leading this initiative is the Safer Medicines Trust, an independent patient safety organization and registered charity (number 1039411). For more information see'

Click here to learn more about Cyprotex's modelling technologies.

For further information:

Cyprotex PLC
Tel: +44 (0) 1625 505 100
Dr Anthony Baxter, Chief Executive Officer
John Dootson, Chief Financial Officer
Mark Warburton, Chief Operating Officer and Legal Counsel

Singer Capital Markets Limited (broker to Cyprotex)
Tel: +44 (0) 203 205 7500
Shaun Dobson

Claes Spang

Financial Dynamics
Tel: +44 (0) 20 7831 3113
Ben Brewerton
Ben Atwell
Mo Noonan

Notes to Editors:

Cyprotex PLC

Cyprotex is the world's largest contract research organisation (CRO) specialising in ADME Tox, which is the analysis of the Absorption, Distribution, Metabolism, Excretion, and Toxicity properties of potential drugs, cosmetics, and agrochemicals. It is the only company in the world with in-house capabilities for both in vitro (test tube) and in silico (computer modelling) ADME Tox. Cyprotex was founded in 1999 and listed on the AIM in 2002. It has laboratories in Macclesfield, Cheshire, UK (near Manchester), and Watertown, Massachusetts, USA (near Boston), making it one of only three ADME Tox CROs with international operations.


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