Shareholder Ronald L. Chez Comments on Recent Repligen Developments

Today Ronald L. Chez, owner of 9.2% of Repligen Corporation RGEN, issued the following statement: "As a result of my constructive recent conversation with Karen Dawes, Chairperson of Repligen's Board, I plan to discuss my proxy proposal regarding the reduction from 50% to 20% of outstanding shares, to call a special meeting." In addition, "I plan to discuss strategic alternatives for Repligen in light of the positive Phase 1 results of 3039 for the potential treatment of Spinal Muscular Atrophy (SMA), and the decision of the FDA to require additional clinical trial data for 1068." Mr. Chez added, "I believe Repligen should schedule a conference call at the earliest possible time to discuss the company's plans and strategy in light of these recent developments."