On December 10, 2015, John K. Clarke notified Momenta Pharmaceuticals Inc. that he will retire from the company's Board of Directors, effective December 31, 2015. Mr. Clarke has served as a director since April 2002 and currently serves as a member of the Audit Committee and the Compensation Committee. Mr. Clarke's retirement was not the result of any disagreement with the company on any matter relating to the company's operations, policies or practices.