Agreement Expands Access to Pfizer’s Pre-Competitive Research, Helping to Advance Basic Science

Charles River Laboratories International, Inc. (NYSE: CRL) today announced that it has entered into a marketing and distribution agreement with Pfizer Inc. (NYSE: PFE), the world’s leading biopharmaceutical company, to provide certain Pfizer-developed genetically modified research models to the global biomedical research community. Under this agreement, Charles River will supply a number of pre-competitive, transgenic research models developed by Pfizer across a broad range of therapeutic areas, including neuroscience, diabetes and cardiovascular disease. “Charles River is extremely pleased to partner with Pfizer to further expand our growing portfolio of genetically modified research models that we can make available to our global client base,” said Dr. Iva Morse, Corporate Vice President, Global Research Model Services at Charles River. “The use of genetically modified research models continues to emerge as an important tool to allow scientists in their research to target specific disease states and genetic markers. We appreciate that Pfizer has selected Charles River to bring their unique models to market, and the biomedical research community will undoubtedly benefit from access to Pfizer’s world-class transgenic model portfolio.” Rick Connell, Vice President and Worldwide Head of External Research Solutions Center of Excellence at Pfizer, added, “This agreement with Charles River aligns with Pfizer’s strategy to externalize our precompetitive tools and assets to a broader community of scientists outside of Pfizer’s walls. We collectively share an interest in seeing science advance to enable the continued development of innovative medicines for patients. Charles River is a leader in providing products and services to the biomedical research community, so we expect that our genetically modified models will be delivered to their clients with the highest standards of quality and care for which they are globally recognized.”

Caution Concerning Forward-Looking Statements

This news release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as “anticipate,” “believe,” “expect,” “will,” “may,” “estimate,” “plan,” “outlook,” and “project” and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These statements also include statements regarding the future benefits and opportunities to be derived from Pfizer’s transgenic or genetically modified models, and the acceptance and adoption of these models as drug discovery and development tools. Forward-looking statements are based on Charles River’s current expectations and beliefs, and involve a number of risks and uncertainties that are difficult to predict and that could cause actual results to differ materially from those stated or implied by the forwardlooking statements. Those risks and uncertainties include risks, uncertainties, and other matters found in the Risk Factors detailed in Charles River's Annual Report on Form 10-K as filed on February 23, 2011, as well as other filings we make with the Securities and Exchange Commission. Because forward-looking statements involve risks and uncertainties, actual results and events may differ materially from results and events currently expected by Charles River, and Charles River assumes no obligation and expressly disclaims any duty to update information contained in this news release except as required by law.

About Charles River

Accelerating Drug Development. Exactly. Charles River provides essential products and services to help pharmaceutical and biotechnology companies, government agencies and leading academic institutions around the globe accelerate their research and drug development efforts. Our approximately 7,500 employees worldwide are focused on providing clients with exactly what they need to improve and expedite the discovery, development through first-in-human evaluation, and safe manufacture of new therapies for the patients who need them. To learn more about our unique portfolio and breadth of services, visit www.criver.com.

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Investor Contact:
Susan E. Hardy
Corporate Vice President, Investor Relations