X0306 4 2017-06-21 0 0001374690 ZAFGEN, INC. ZFGN 0001579130 McDonough Cameron Geoffrey C/O ZAFGEN, INC., 175 PORTLAND STREET, 4TH FLOOR BOSTON MA 02114 1 0 0 0 Stock Option (Right to Buy) 3.95 2017-06-21 4 A 0 14500 0.00 A 2027-06-21 Common Stock 14500 14500 D These options were issued under the nonemployee director compensation policy and will vest in full upon the earlier of June 21, 2018 or the date of the 2018 annual meeting of stockholders, subject to the director's continued service on the board of directors. /s/ Laurie Burlingame, Attorney-in-Fact 2017-06-23