EX-32.1 7 spro-ex321_8.htm EX-32.1

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report on Form 10-K of Spero Therapeutics, Inc. (the “Company”) for the period ended December 31, 2017, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

| (1) | The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

| (2) | The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

Date: April 2, 2018 |  | By: | /s/ Ankit Mahadevia, M.D.
|  |  | Ankit Mahadevia, M.D.
|  |  | President and Chief Executive Officer (Principal Executive Officer)