X0306 4 2016-04-01 0 0001374690 ZAFGEN, INC. ZFGN 0001538894 Daniel Thomas O C/O ZAFGEN, INC., 175 PORTLAND STREET, 4TH FLOOR BOSTON MA 02114 1 0 0 0 Stock Option (Right to Buy) 6.70 2016-04-01 4 A 0 24000 0.00 A 2026-04-01 Common Stock 24000 24000 D Stock Option (Right to Buy) 6.70 2016-04-01 4 A 0 3841 0.00 A 2026-04-01 Common Stock 3841 3841 D Stock option shall vest over a three-year period beginning on March 3, 2016 on a monthly basis in arrears, provided that as of each such vesting date, the Reporting Person continues to provide services to the Company. All unvested shares shall become fully vested upon a change in control of the Company. The stock option was issued in lieu of cash fees under the Non-Employee Director Compensation Policy pursuant to a Non-Qualified Stock Option Agreement. 367 shares of the stock option shall be vested as of April 1, 2016 and the remaining stock option shall vest over the remainder of the 2016 calendar year starting from April 1, 2016 on a quarterly basis in arrears. /s/ Laurie Burlingame (Attorney-In-Fact) 2016-04-04