ZFGN Zafgen Inc

Zafgen, Inc. (Nasdaq:ZFGN) (the “Company”) a clinical-stage biopharmaceutical company leveraging its proprietary knowledge of MetAP2 systems biology to develop novel therapies for patients affected by a range of metabolic diseases, today announced that on April 2, 2019, the Company granted to Priya Singhal, M.D., M.P.H., the Company’s Head of Research and Development, an option to purchase 375,000 shares of the Company’s common stock, with 25% of the option shares vesting on March 4, 2020 and the balance vesting in equal monthly installments over the next three years, subject to her continued service to the Company through each vesting date. The option is subject to acceleration upon a change in control. The grant was made as a stand-alone inducement award agreement outside of the 2014 Stock Option and Incentive Plan as a material inducement to Dr. Singhal’s acceptance of employment with the Company in accordance with NASDAQ Listing Rule 5635(c)(4).

About Zafgen Zafgen (Nasdaq:ZFGN) is a clinical-stage biopharmaceutical company leveraging its proprietary MetAP2 biology platform to develop novel therapies for patients affected by complex metabolic diseases. Zafgen has pioneered the study of MetAP2 inhibitors in both common and rare metabolic disorders and is currently advancing programs for type 2 diabetes, Prader-Willi syndrome and liver diseases. Learn more at www.zafgen.com.

Media/Investor Relations Contacts: Zafgen, Inc. Patricia Allen Chief Financial Officer 617-648-9792

Media Krystle Gibbs Ten Bridge Communications   krystle@tenbridgecommunications.com 508-479-6358

Investors John Woolford Westwicke, An ICR Company john.woolford@westwicke.com 443-213-0506