October 30, 2017
U.S. Securities and Exchange Commission
Division of Corporation Finance
100 F Street, N.E.
Washington, D.C. 20549
| Attn: | Mary Beth Breslin, Branch Chief |
Chris Edwards
| Re: | Spero Therapeutics, Inc. (the “Company”) |
| Registration Statement on Form S-1 |
| File No. 333-220858 |
Acceleration Request
Requested Date: November 1, 2017
Requested Time: 4:00 p.m. Eastern Daylight Time
Ladies and Gentlemen:
As representatives of the several underwriters of the Company’s proposed initial public offering, we hereby join the Company’s request that the effective date of the above-referenced Registration Statement be accelerated so that the above-referenced Registration Statement will be declared effective at 4:00 p.m., Eastern Daylight Time, on November 1, 2017, or as soon thereafter as is practicable.
Pursuant to Rule 460 of the General Rules and Regulations of the Securities and Exchange Commission under the Securities Act of 1933, as amended, we wish to advise you that we have effected the following distribution of the Company’s Preliminary Prospectus, dated October 23, 2017, through the date hereof:
Preliminary Prospectus dated October 23, 2017:
1,071 copies to prospective underwriters, institutional investors, dealers and others
The undersigned advises that it has complied and will continue to comply, and that it has been informed by the participating underwriters and dealers that they have complied with and will continue to comply, with the requirements of Rule 15c2-8 under the Securities Exchange Act of 1934, as amended.
[Remainder of Page Intentionally Left Blank]
Very truly yours,
As Representatives of the several Underwriters
MERRILL LYNCH, PIERCE, FENNER & SMITH
INCORPORATED
| By: | /s/ Richard A. Diaz | |
| Name: Richard A. Diaz | ||
| Title: Vice President | ||
| COWEN AND COMPANY, LLC | ||
| By: | /s/ Jamie Streator | |
| Name: Jamie Streator | ||
| Title: Managing Director | ||
[Signature Page to Underwriter Acceleration Request]