Filed by Charles River Laboratories International, Inc.
pursuant to Rule 14a-12
of the Securities Exchange Act of 1934

Subject Company: Charles River Laboratories International, Inc.
(Commission File No.: 001-15943)

Charles River Plans to Acquire WuXi AppTec
April, 26, 2010 - Charles River is pleased to announce plans to acquire WuXi AppTec, creating the only global CRO to offer fully integrated drug development services from molecule creation to first-in-human testing. The combined company, which will retain the name Charles River, will offer enhanced support for your research programs through our comprehensive portfolio of early-stage drug development services and expanded global presence.
WuXi AppTec is a leading drug research and development outsourcing company with significant expertise in discovery chemistry.  It was established in 2000 and has steadily grown to more than 4,000 employees with operations in China and the United States. Together with Charles River, a leading global provider of both research models and associated services as well as preclinical drug development services, the combined company will have 12,000 employees, providing unparalleled support for your early-stage drug development needs.
We regard this as a transformational transaction that creates value for customers by enabling you to obtain comprehensive support for your early-stage drug development needs from one company with extensive scientific expertise, depth and breadth.  Further, we will be able to provide you with expanded global access to our integrated portfolio of products and services, enabling you to work within or across the locales you choose, in North America, Europe or China.
This strategic combination brings together two companies with the shared mission of supporting the acceleration of your drug development efforts and a commitment to exceeding your expectations.
We will continue to share additional details in the next few days on how Charles River will set a new standard in the outsourced drug development services industry. In the meantime, please view more information on, or contact your sales representative with any questions.
We look forward to continuing to work with you and to further supporting your early-stage drug development needs.
Forward-Looking Statements

This document 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,” “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 are based on current expectations and beliefs of Charles River Laboratories International, Inc. (Charles River) and WuXi PharmaTech (Cayman) Inc. (WuXi), and 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. Those risks and uncertainties include, but are not limited to: 1) the possibility that the companies may be unable to obtain stockholder or regulatory approvals required for the combination; 2) problems may arise in successfully integrating the businesses of the two companies; 3) the acquisition may involve unexpected costs; 4) the combined company may be unable to achieve cost synergies; 5) the businesses may suffer as a result of uncertainty surrounding the acquisition; and 6) the industry may be subject to future regulatory or legislative actions and other risks that are described in Securities and Exchange Commission (SEC) reports filed or furnished by Charles River and WuXi.
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 WuXi. Charles River and WuXi assume no obligation and expressly disclaim any duty to update information contained in this filing except as required by law.
Additional Information
This document may be deemed to be solicitation material in respect of the proposed combination of Charles River and WuXi. In connection with the proposed  transaction, Charles River will file a preliminary proxy statement and a definitive proxy statement with the SEC. The information contained in the preliminary filing will not be complete and may be changed. Before making any voting or investment decisions, investors and security holders are urged to read the definitive proxy statement when it becomes available and any other relevant documents filed with the SEC because they will contain important information. The definitive proxy statement will be mailed to the shareholders of Charles River seeking their approval of the proposed transaction. Charles River’s shareholders will also be able to obtain a copy of the definitive proxy statement free of charge by directing a request to: Charles River Laboratories, 251 Ballardvale Street, Wilmington, MA 01887, Attention: General Counsel. In addition, the preliminary proxy statement and definitive proxy statement will be available free of charge at the SEC’s website, or shareholders may access copies of the documentation filed with the SEC by Charles River on Charles River’s website at
Charles River and its directors and executive officers and other members of management and employees may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information regarding Charles River’s directors and executive officers is available in Charles River’s proxy statement for its 2010 annual meeting of shareholders, which was filed with the SEC on March 30, 2010. Information regarding the persons who may, under the rules of the SEC, be considered participants in the solicitation of Charles River shareholders in connection with the proposed transaction will be set forth in the preliminary proxy statement when it is filed with the SEC.
This document does not constitute an offer of any securities for sale or a solicitation of an offer to buy any securities. The Charles River shares to be issued in the proposed transaction have not been and will not be registered under the Securities Act of 1933, as amended (the “Securities Act”), and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. Charles River intends to issue such Charles River shares pursuant to the exemption from registration set forth in Section 3(a)(10) of the Securities Act.