Repligen Corporation (NASDAQ: RGEN) announced today that Dr. Walter C. Herlihy, President and Chief Executive Officer of Repligen will host a conference call and webcast on Friday, October 28, 2011 at 8:30 am EDT, to discuss the second quarter financial results for fiscal year 2012 and provide a quarterly update of the company. This call is being webcast by Thomson/CCBN and can be accessed via Repligen’s website at www.repligen.com. If you are unable to access the webcast, you may listen live by calling (866) 831-6267 for domestic calls and (617) 213-8857 for international calls. Participants must provide the following passcode: 27485966. For those who cannot participate in the live conference call, an archive of the audio webcast will be available shortly after the call on Repligen’s website www.repligen.com. About Repligen Corporation Repligen Corporation is a leading supplier of critical technologies and ingredients used to manufacture biologic drugs. Repligen also applies its expertise in biologic development to Secreflo™, a novel imaging candidate for the diagnosis of a variety of pancreatic diseases. In addition, we have two early stage CNS rare disease programs which are advancing into Phase 1 clinical trials. 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.