Karen A. Dawes Elected as Repligen Co-chairperson of the Board of Directors Repligen Corporation

Repligen Corporation (NASDAQ: RGEN) announced today that Ms. Karen A. Dawes has been elected to serve as co-chairperson of the Board of Directors along with Mr. Alexander Rich, M.D. Ms. Daweshas served as a Director of Repligen since September of 2005 and has extensive experience in the pharmaceutical and biotechnology industry in the development of worldwide marketing and sales teams and commercialization strategies.
“Karen’s commercial expertise, strategic vision and leadership skills have been a highly valuable resource to our Company,” stated Walter C. Herlihy, President and Chief Executive Officer of Repligen Corporation. “I am very pleased to have Karen and Alex share the leadership of our Board as we continue to transition from a development stage organization to an integrated company with commercial, manufacturing and product development capabilities.”

Ms. Dawes has held numerous executive level positions including Senior Vice President and U.S. Business Group Head for Bayer Corporation’s U.S. Pharmaceuticals Group, Senior Vice President, Global Strategic Marketing for Wyeth, Vice President, Commercial Operations for Genetics Institute, Inc. and Vice President, Marketing of the Pratt Division of Pfizer, Inc. Ms. Dawes has directed the launch of numerous pharmaceuticals including Glucotrol/Glucotrol XL®, Zoloft®, and Cardura® for Pfizer. She earned an MBA degree from Harvard Business School and holds a bachelor’s and master’s degree in English from Simmons College, Boston. Ms. Dawes is currently President of Knowledgeable Decisions LLC, a management consulting firm and a Director of Depomed, Inc, Inspiration Biopharmaceuticals, Inc. and Seaside Therapeutics LLC.

About Repligen Corporation

Repligen Corporation is a biopharmaceutical company focused on building an integrated company by developing and marketing innovative drugs that deliver the benefits of protein therapies in the fields of neurology and gastroenterology. We have a core competency in the development and manufacturing of biologics products, which is the basis for our bioprocessing business and we have out-licensed certain biologics intellectual property, which provide ongoing sources of revenue. Repligen’s corporate headquarters are located at 41 Seyon Street, Building #1, Suite 100, Waltham, MA 02453. Additional information may be requested at www.repligen.com.

This press release contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements in this release do not constitute guarantees of future performance. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements regarding future financial performance and position, management’s strategy, plans and objectives for future operations, plans and objectives for product development, plans and objectives for present and future clinical trials and results of such trials, plans and objectives for regulatory approval, litigation, intellectual property protection, product development, manufacturing plans and performance, projected changes in the size of our markets, our market share and product sales and other statements identified by words like “believe,” “expect,” “may,” “will,” “should,” “seek,” or “could” and similar expressions, constitute forward-looking statements. Such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated, including, without limitation, risks associated with: the success of our clinical trials; our ability to develop and commercialize products; our ability to obtain required regulatory approvals; the success of current and future collaborative relationships; the market acceptance of our products; our ability to compete with larger, better financed pharmaceutical and biotechnology companies; new approaches to the treatment of our targeted diseases; our expectation of incurring continued losses; our uncertainty of product revenues and profits; our ability to generate future revenues; our ability to raise additional capital to continue our drug development programs; our compliance with all Food and Drug Administration regulations; our ability to obtain; maintain and protect intellectual property rights for our products; the risk of litigation regarding our intellectual property rights; our limited sales and manufacturing capabilities; our dependence on third-party manufacturers and value added resellers; our ability to hire and retain skilled personnel; our volatile stock price; and other risks detailed in Repligen’s annual report on Form 10-K on file with the Securities and Exchange Commission and the other reports that Repligen periodically files with the Securities and Exchange Commission. Actual results may differ materially from those Repligen contemplated by these forward-looking statements. These forward looking statements reflect management’s current views and Repligen does not undertake to update any of these forward-looking statements to reflect a change in its views or events or circumstances that occur after the date hereof except as required by law.