CERTIFICATIONS PURSUANT TO 18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
In connection with this Annual Report on Form 10-K of Karyopharm Therapeutics Inc. (the
Company) for the year ended December 31, 2017, as filed with the Securities and Exchange Commission on the date hereof (the Report), each of the undersigned officers of the Company hereby certifies, pursuant to 18 U.S.C.
(section) 1350, as adopted pursuant to (section) 906 of the Sarbanes-Oxley Act of 2002, that to the best of his knowledge:
(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and
(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results
of operations of the Company.
|Dated: March 15, 2018|
/s/ Michael G. Kauffman
|Michael G. Kauffman, M.D., Ph.D.|
|Chief Executive Officer|
/s/ Michael F. Falvey
Michael F. Falvey
Executive Vice President, Chief Financial Officer and