Charles River Enters Into Cloning Partnership With Advanced Cell Technology.

Business/Technology Editors & Health/Medical Writers

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WILMINGTON, Mass.--(BW HealthWire)--July 5, 2001

Charles River Laboratories International, Inc. (NYSE: CRL), through its wholly-owned subsidiary Charles River Laboratories, Inc., today announced that it has entered into a technology partnership agreement with Advanced Cell Technology, Inc. (ACT), to apply ACT's novel transgenic technologies to the creation of cloned rat research models used in diabetes and cardiovascular disease research. In December 2000, Charles River entered into a complementary technology partnership with Tufts University School of Veterinary Medicine, to apply a novel cloning technology to an immunodeficient mouse model used in cancer and infectious disease research. Cloned rat and mouse models are expected to offer biomedical researchers a more targeted and predictable research tool for use in the discovery and development of new drugs to treat human disease.

The initial cloning work at ACT will be done in rat models currently bred by Charles River that are frequently used in diabetes and cardiovascular research. In exchange for sponsoring a research commercialization program, Charles River will license ACT's technology for the purpose of breeding and selling or licensing cloned rat models for research. Efficient cloning of high value research models through ACT's proprietary techniques is expected to increase the utility of these models to researchers, as well as improve the efficiency with which they are produced at Charles River. In many areas of drug discovery a cloned research model is expected to improve on existing models by eliminating variability and thereby improving the quality and consistency of research results.

James C. Foster, Chairman & CEO, commented: "We're very pleased to be working with ACT in the area of animal cloning research. This agreement reflects our strategy of developing new growth platforms through external R&D partnerships with scientific leaders. We believe ACT and its world class scientific team is in a unique position to develop what we hope will be the first commercially available cloned rat. We expect the cutting edge work being done by ACT and our other scientific partners will lead to both significant benefits to researchers who use our research models in their drug discovery and development work, and also lead to improved efficiency of production of high value models at Charles River."

Charles River Laboratories, based in Wilmington, Massachusetts, is a leading provider of critical research tools and integrated support services that enable innovative and efficient drug discovery and development. The Company is the global leader in providing the animal research models required in research and development for new drugs, devices and therapies. The Company also offers a broad and growing portfolio of biomedical products and services that enable customers to reduce cost, increase speed, and enhance productivity and effectiveness in drug discovery and development. Charles River's customer base spans over 50 countries, and includes all of the major pharmaceutical and biotechnology companies, as well as many leading hospitals and academic institutions. The Company operates 76 facilities in 15 countries worldwide.

Advanced Cell Technology, Inc., headquarted in Worcester, MA, is engaged in the research and development of technologies for the production of transgenic animals with applications in pharmaceutical protein production and cell and organ transplant therapy. Formed in 1994, ACT's initial focus is in three program areas. First, to create cloned transgenic cows. Second, to produce cloned transgenic animals as donors of cells for transplant therapies. And third to lead in the application of human cell nuclear transfer to produce cells and tissues genetically identical to patients with various life-threatening illnesses. ACT has several patents on its cloning technology.

This document contains "forward looking statements." Such statements involve a number of risks and uncertainties that could cause actual results to differ materially from those stated or implied by the forward looking statements, including risks specific to the matters described herein, such as failure to commercialize research and development plans, changes in legislative and regulatory rules and restrictions governing the application of cloning technology to animal research models, opposition of special interest groups, intellectual property matters, and other general risks impacting the business of Charles River that are described in the Risk Factors contained in Company's periodic filings with the SEC, including Form S-3 filed on June 25, 2001. The Company disclaims any intent or obligation to update forward looking statements, and otherwise claims the safe harbor protections for forward looking statements afforded under The Private Securities Litigation Reform Act of 1995.