Repligen Appoints Jonathan I. Lieber as CFO

- Former CFO of Xcellerex, Inc. Joins Repligen Executive Management Team -

Repligen Appoints Jonathan I. Lieber as CFO

<0> Repligen CorporationSondra S. Newman, 781-419-1881Director Investor Relations </0>

Repligen Corporation (NASDAQ:RGEN) today announced the appointment of Jonathan I. Lieber to the position of Chief Financial Officer and Treasurer, effective immediately. Mr. Lieber most recently held the position of CFO and Treasurer at Xcellerex, Inc., a supplier of bioprocessing products and disposable biomanufacturing technologies, which was acquired in May 2012 by GE Healthcare. He will be responsible for leading Repligen’s financial activities, including long-term financial strategy and risk management. Repligen’s current CFO William J. Kelly has been named Chief Accounting Officer, overseeing the Company’s accounting and management reporting functions, as well as its internal controls.

“We are pleased to welcome Jonathan Lieber to the CFO role,” said Walter C. Herlihy, Ph.D., President and Chief Executive Officer at Repligen. “Over the past nine months, Repligen has become a profitable, significantly larger and more complex multinational organization. As the Company enters its next phase of growth, Mr. Lieber brings a particularly relevant skill set to the management team. His combined life sciences and capital markets expertise will be major assets to the Company as we advance on our strategy to further expand Repligen’s bioprocessing business and deliver top-tier financial performance.”

During his three-year tenure with Xcellerex, Mr. Lieber led the company’s accounting, finance, legal and corporate communications activities. He restructured the finance department and implemented business processes to support substantial revenue growth. Prior to his role with Xcellerex, Mr. Lieber was with Altus Pharmaceuticals for seven years, most recently as Senior Vice President, CFO and Treasurer. At Altus, he had responsibility for accounting and finance, and for managing several administrative departments. Mr. Lieber led all capital raising activities at the company, resulting in net proceeds to Altus of $250 million, including its $110 million initial public offering. Prior to joining Altus, Mr. Lieber served as vice president of SG Cowen’s Healthcare Investment Banking Group, where he originated and executed on multiple corporate financings and merger & acquisition transactions. Mr. Lieber has been involved in healthcare financings totaling over $3 billion in common stock and over $500 million in initial public offerings. He received a B.S. in business administration and finance from Boston University and an M.B.A. in finance from New York University Stern School of Business.

In connection with Mr. Lieber’s appointment, Repligen granted Mr. Lieber an inducement equity award outside of Repligen’s 2012 Stock Option and Incentive Plan in accordance with NASDAQ Listing Rule 5635(c)(4). This award, which was approved by Repligen’s compensation committee and is consistent with Repligen’s past practice for new executive hires, is for 15,000 shares of restricted stock which will vest in full on the first anniversary of Mr. Lieber’s start date with Repligen.

Repligen Corporation is a life sciences company focused on the development, production and commercialization of products used in the process of manufacturing biological drugs. Our bioprocessing products are sold to major life sciences and biopharmaceutical companies worldwide. We are a leading manufacturer of Protein A, a critical reagent used to manufacture monoclonal antibody-based therapeutics. We also supply several growth factor products used to increase cell culture productivity in biomanufacturing. In the burgeoning area of disposable biomanufacturing technologies, we have developed and market a series of OPUS™ (Open Platform User Specified) single-use chromatography columns used in the biologics purification process. In addition to our core bioprocessing business, we have a portfolio of clinical-stage partnering assets, including two central nervous system orphan drug candidates and a pancreatic imaging agent in Phase 3 development. Repligen’s corporate headquarters are located in Waltham, MA, USA; we have an additional manufacturing facility in Lund, Sweden. For more information, please visit our website at .