Arsanis, Inc.
890 Winter Street, Suite 230
Waltham, MA 02451
November 13, 2017
VIA EDGAR
Securities and Exchange Commission
Division of Corporation Finance
100 F Street, N.E.
Washington, D.C. 20549
| Re: | Arsanis, Inc. |
| Registration Statement on Form S-1 |
| File No. 333-221050 |
| Request for Acceleration |
Ladies and Gentlemen:
Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Arsanis, Inc. (the “Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-1 (File No. 333-221050), as amended (the “Registration Statement”), so that it may become effective at 4:00 p.m. Eastern time on November 15, 2017, or as soon thereafter as practicable.
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| Very truly yours, | ||||
| ARSANIS, INC. | ||||
| By: | /s/ René Russo | |||
| Name: | René Russo | |||
| Title: | President and Chief Executive Officer | |||
Signature Page to Acceleration Request