X0306 4 2016-06-23 0 0001235010 MOMENTA PHARMACEUTICALS INC MNTA 0001237257 DOWNEY BRUCE C/O MOMENTA PHARMACEUTICALS, INC. 675 WEST KENDALL STREET CAMBRIDGE MA 02142 1 0 0 0 Common Stock 2016-06-23 4 A 0 5500 0 A 15500 D Stock Option (Right to Buy) 10.97 2016-06-23 4 A 0 11000 0 A 2017-06-23 2026-06-23 Common Stock 11000 11000 D Represents 5,500 shares of restricted common stock, $0.0001 par value per share, awarded pursuant to the Company's 2013 Stock Incentive Plan, 100% of the shares of restricted common stock shall vest on the first anniversary of the grant date, subject to Mr. Downey's continued service to the Company. Represents an option granted by the Company pursuant to the Company's 2013 Stock Incentive Plan. The stock option will vest and become exercisable on the first anniversary of the grant date, subject to Mr. Downey's continued service to the Company. /s/ Marie T. Washburn as attorney in fact 2016-06-27