EpiStem Ltd to Present Erlotinib Biomarker Data at American Association for Cancer Research Meeting

MANCHESTER, UNITED KINGDOM--(Marketwire - April 14, 2009) - Epistem plc (LSE: EHP), the UK biotechnology and contract research company, will present results from its recently completed preclinical plucked hair biomarker study at the American Association for Cancer Research (AACR) 100th Annual Meeting in Denver, Colorado on Sunday 19th April 2009 at 1pm (abstract number 1753) This study was completed successfully on Erlotinib, commonly known as Tarceva®, a small molecule designed to target the Epithelial Growth Factor Receptor 1 (HER1/EGFR) pathway and a treatment for small cell lung and prostate cancer.

Data will be presented by Dr. Ged Brady to demonstrate that drug-induced changes in gene expression are observed in plucked hairs following Erlotinib treatment, as early as 6 hours after the first administration. Using DNA array analysis of plucked hairs the Biomarker Division at Epistem have identified a “core gene set” which are changed in response to treatment. These gene changes are biomarkers which provide expression based analysis of pharmacodynamic (PD) change in response to Erlotinib.

This biomarker expression data can assist the drug development process by providing a quantitative measure of drug exposure, and drug effects downstream of the target. There is potential to also study the differential effect of new compounds in development versus Erlotinib in the clinical setting.

“Epistem’s proprietary plucked hair biomarker platform provides a simple and effective means of measuring biological response in epithelial tissue. These results provide further support to the clinical relevance of hair as surrogate tissue that is readily accessible in early clinical studies,” said Lydia Meyer-Turkson, Director of the Biomarker Division at Epistem. “We are pleased that the data demonstrate the relevance of plucked hair as a PD biomarker for compounds in development that are designed to inhibit tyrosine kinase activity” she added.

The abstract will be available on request following the presentation at AACR.

Notes to Editors:

About Epistem

Epistem is a biotechnology company commercialising its expertise in epithelial stem cells in the areas of oncology, gastrointestinal diseases and dermatological applications. Epistem develops innovative therapeutics and biomarkers and provides contract research services to drug development companies. The Group’s expertise is focused on the regulation of adult stem cells located in epithelial tissue, which includes the gastrointestinal tract, skin, hair follicles, breast and prostate. Epistem does not conduct research in the areas of embryonic stem cells or stem cell transplantation.

Epistem operates three distinct business divisions, Contract Research Services, Novel Therapies and Biomarkers.

Biomarkers

The Biomarker division provides services to drug development companies using its plucked hair biomarker technology. The Company’s knowledge of the behaviour of epithelial cells and drug-induced gene expression change is used to measure drug effects during treatment. Changes in gene expression can be detected within hours and at low levels of chemotherapy or radiation. The highly sensitive Biomarker technology is based on using mRNA extracted from the bulb of cells at the base of a single hair follicle as a minimally invasive process to measure gene expression changes in epithelial tissue.