X0306 4 2016-12-19 0 0001374690 ZAFGEN, INC. ZFGN 0001441724 Heller Frances K C/O ZAFGEN, INC. 175 PORTLAND STREET, 4TH FLOOR BOSTON MA 02114 1 0 0 0 Common Stock 2016-12-19 4 P 0 10000 3.229 A 30000 D The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $3.20 to $3.24, inclusive. The reporting person undertakes to provide to Zafgen, Inc., any security holder of Zafgen, Inc., or the staff at the Securities and Exchange Commission, upon request, full information regarding the number of share purchases at each separate price within the ranges set forth herein. /s/ Laurie Burlingame, Attorney-In-Fact 2016-12-20