Sienna Biopharmaceuticals, Inc.
30699 Russell Ranch Road, Suite 140
Westlake Village, California 91362
August 10, 2018
VIA EDGAR
Securities and Exchange Commission
Division of Corporation Finance
100 F Street, N.E.
Washington, DC 20549
Attention: Irene Paik
| Re: | Sienna Biopharmaceuticals, Inc. |
Registration Statement on FormS-3 (RegistrationNo. 333-226595) |
Ladies and Gentlemen:
In accordance with Rule 461 of Regulation C of the General Rules and Regulations under the Securities Act of 1933, as amended, we hereby request acceleration by the Securities and Exchange Commission (the “Commission”) of the effective date of the above-referenced Registration Statement on FormS-3 (the “Registration Statement”) of Sienna Biopharmaceuticals, Inc. (the “Company”). We respectfully request that the Registration Statement become effective as of 4:00 p.m., Washington, D.C. time, on August 14, 2018, or as soon as practicable thereafter.
Thank you for your assistance in this matter.
| Very truly yours, | ||
| Sienna Biopharmaceuticals, Inc. | ||
| By: | /s/ John W. Smither | |
| John W. Smither | ||
| Chief Financial Officer | ||
