Repligen Corporation (NASDAQ:RGEN) today announced that it will support an amended stockholder proposal based upon an agreement with Ronald L. Chez, the proponent of the proposal. Mr. Chez submitted an amended proposal to increase the proposed threshold necessary for calling a special meeting of stockholders to the holders of 30% of Repligen’s voting shares, as compared to a 20% threshold in his original proposal. In consideration of the change to Mr. Chez’s proposal, Repligen’s board of directors agreed to recommend that Repligen stockholders vote “FOR” this amended stockholder proposal. In addition, Mr. Chez agreed to vote all of his shares of Repligen stock in accordance with the recommendations of Repligen’s board of directors with respect to each of the proposals to be acted upon at the 2012 annual meeting of Repligen’s stockholders. “Repligen listens to and values the input of all stockholders,” stated Walter C. Herlihy, Ph.D., President and Chief Executive Officer of Repligen. “We believe the amended proposal is a testament to that and further enables the board and management to run Repligen in an effective manner.” “I am pleased with the resolution of this matter which encompassed the vote necessary for special meetings, changes to the Company’s policy requiring the CEO and other directors to own stock and a clarification on bonus goals,” stated Mr. Chez. “I believe this amended proposal, if adopted, will enhance the alignment of the board’s and management’s interests with those of its shareholders.” Stockholders will be receiving new proxy cards. Those stockholders who have already delivered proxies may change their votes, including in respect of the amended stockholder proposal (proposal 5) in light of this agreement with Mr. Chez. Unless a stockholder delivers a new proxy, shares will be voted in accordance with the instructions on previously delivered proxies, including in respect of proposals 1 through 4 which have not been amended.