KARYOPHARM THERAPEUTICS INC.

85 WELLS AVENUE, SECOND FLOOR

NEWTON, MA 02459

April 22, 2019

Via EDGAR

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, D.C. 20549

 

Re:	Karyopharm Therapeutics Inc.

Post-Effective Amendment No. 2 to Form S-3 Registration Statement

File No. 333-226038

Request for Acceleration

Ladies and Gentlemen:

Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Karyopharm Therapeutics Inc. (the “Registrant”) hereby requests acceleration of the effective date of its Post-Effective Amendment No. 2 to Form S-3 Registration Statement (File No. 333-226038), so that it may become effective at 4:00 p.m. Eastern time on April 24, 2019, or as soon thereafter as practicable.

 

Very truly yours,   Karyopharm Therapeutics Inc.
By:		/s/ Christopher B. Primiano
Name: Title:		Christopher B. Primiano Executive Vice President, Chief Business Officer, General Counsel and Secretary