J.P. Morgan Securities LLC
383 Madison Avenue
New York, New York 10179
Cowen and Company, LLC
599 Lexington Avenue
New York, New York 10022
July 24, 2017
VIA EDGAR
Securities and Exchange Commission
Division of Corporation Finance
100 F Street, N.E.
Washington, D.C. 20549
| Attention: | Suzanne Hayes, Assistant Director | |
| Mary Beth Breslin, Legal Branch Chief | ||
| Johnny Gharib, Senior Counsel | ||
| Sharon Blume, Accounting Branch Chief | ||
| Christine Torney, Senior Staff Accountant | ||
| Re: | Sienna Biopharmaceuticals, Inc. | |
| Registration Statement on Form S-1 | ||
| File No. 333-219142 | ||
Ladies and Gentlemen:
In accordance with Rule 461 under the Securities Act of 1933, as amended (the “Act”), we, as representatives of the several underwriters, hereby join in the request of Sienna Biopharmaceuticals, Inc. (the “Company”) for acceleration of the effective date of the above-named Registration Statement so that it will be declared effective at 4:00 PM, Eastern Time, on July 26, 2017, or as soon thereafter as practicable, or at such other time as the Company or its outside counsel, Latham & Watkins LLP, request by telephone that such Registration Statement be declared effective.
Pursuant to Rule 460 under the Act, we, as representatives of the several underwriters, wish to advise you that we have effected the following distribution of the Company’s preliminary prospectus dated July 17, 2017:
| (i) | Dates of distribution: July 17, 2017 through the date hereof |
| (ii) | Number of prospective underwriters to which the preliminary prospectus was furnished: 3 |
| (iii) | Number of prospectuses furnished to investors: approximately 1,963 |
| (iv) | Number of prospectuses distributed to others, including the Company, the Company’s counsel, independent accountants, and underwriters’ counsel: approximately 100 |
The undersigned advise that they have complied and will continue to comply, and each underwriter and dealer has advised the undersigned that it has complied and will continue to comply, with Rule 15c2-8 under the Securities Exchange Act of 1934, as amended.
[Signature page follows]
* * * *
| Very truly yours, | ||
| J.P. MORGAN SECURITIES LLC COWEN AND COMPANY, LLC
Acting severally on behalf of themselves and the several underwriters | ||
| J.P. MORGAN SECURITIES, LLC | ||
| By: | /s/ Benjamin H. Burdett | |
| Name: Benjamin H. Burdett | ||
| Title: Executive Director | ||
| COWEN AND COMPANY, LLC | ||
| By: | /s/ James Streator, III | |
| Name: James Streator, III | ||
| Title: Managing Director | ||
[Signature Page to Underwriters’ Acceleration Request]