Establishes Charles River as a Premier Source for Immunology Contract Research Services.

WILMINGTON, Mass.  (— Charles River Laboratories International, Inc. (NYSE: CRL) today announced that it has acquired KWS BioTest, a leading contract research organization (CRO) specializing in in vitro and in vivo discovery testing services for immuno-oncology and inflammatory and infectious diseases. The addition of KWS enhances Charles River’s discovery expertise, with complementary offerings that provide our clients with additional tools in the active therapeutic research areas of oncology and immunology.

James C. Foster, Chairman, President and Chief Executive Officer of Charles River, said, “The addition of KWS strategically expands Charles River’s existing discovery capabilities in the field of immunology, which is critical given the importance of new therapies which harness the human immune system. In addition to enhancing our position as the premier single-source provider for a broad portfolio of discovery services, KWS increases our ability to support clients’ early-stage drug research in critical therapeutic areas, and expands our geographic footprint in the United Kingdom.”

The purchase price was approximately £15 million in cash (approximately $20 million based on current exchange rates), subject to certain post-closing adjustments. In addition to the initial purchase price, the transaction includes a potential additional payment of up to £3 million based on future performance (approximately $4 million based on current exchange rates). The transaction is not expected to be material to 2018 GAAP or non-GAAP results from operations.

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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. Forward-looking statements include statements in this press release regarding the acquisition of KWS BioTest and Charles River’s expectations with respect to the impact of KWS BioTest on the Company and its product and service offerings; as well as Charles River’s future growth in the areas of oncology, immunology, inflammation, or infectious disease drug research. 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 forward-looking statements. A further description of these risks, uncertainties, and other matters can be found in the Risk Factors detailed in Charles River's Annual Report on Form 10-K as filed on February 14, 2017, 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.

________________________________________________________________________________________________Contacts
Charles River Laboratories International, Inc.
Investor Contact:
Susan E. Hardy
Corporate Vice President, Investor Relations
Tel: +1 781 222 6190
Email: susan.hardy@crl.com
or
Media Contact:
Amy Cianciaruso
Corporate Vice President, Public Relations
Tel: +1 781 222 6168
Email: amy.cianciaruso@crl.com