10-Q/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q/A

(Amendment No. 1)

(Mark One)

xQUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended September 30, 2014

OR

oTRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from              to             

Commission file number: 001-36167

Karyopharm Therapeutics Inc.

(Exact name of registrant as specified in its charter)

Delaware	26-3931704
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification Number)

85 Wells Avenue, 2nd Floor Newton, MA	02459
(Address of principal executive offices)	(Zip Code)

(617) 658-0600

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x  No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes x  No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer o	Accelerated filer o
Non-accelerated filer x (Do not check if a smaller reporting company)	Smaller reporting company o

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o  No x

As of November 4, 2014 there were 32,700,563 shares of Common Stock, $0.0001 par value per share, outstanding.

Explanatory Note

The purpose of this Amendment No. 1 to Karyopharm Therapeutics Inc.’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2014, filed with the Securities and Exchange Commission on November 10, 2014 (the “Form 10-Q”), is solely to add references to Exhibit Nos. 10.1, 10.2 and 10.3 that were inadvertently omitted from the Form 10-Q.  Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, new certifications of our principal executive officer and principal financial officer are being filed as exhibits to this Form 10-Q/A.

No other changes have been made to the Form 10-Q. This Amendment No. 1 to the Form 10-Q speaks as of the original filing date of the Form 10-Q, does not reflect events that may have occurred subsequent to the original filing date, and does not modify or update in any way disclosures made in the Form 10-Q.

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EXHIBIT INDEX

Exhibit		Incorporated by Reference				Filed
Number	Description of Exhibit	Form	File Number	Data of Filing	Exhibit Number	Herewith
10.1	Offer Letter, dated July 7, 2014, between Karyopharm Therapeutics Inc. and Mr. Justin Renz.	8-K	001-36167	August 8, 2014	10.1
10.2	Consulting Agreement, dated August 7, 2014, between Karyopharm Therapeutics Inc. and Mr. Paul Brannelly.	8-K	001-36167	August 8, 2014	10.2
10.3	Separation Agreement, dated August 7, 2014, between Karyopharm Therapeutics Inc. and Mr. Paul Brannelly.	8-K	001-36167	August 8, 2014	10.3
31.1	Certification of principal executive officer pursuant to Rule 13a-14(a)/15d-14(a) of the Securities Exchange Act of 1934, as amended.					X
31.2	Certification of principal financial officer pursuant to Rule 13a-14(a)/15d-14(a) of the Securities Exchange Act of 1934, as amended.					X
32.1	Certification of principal executive officer pursuant to 18 U.S.C. §1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.	10-Q	001-36167	November 10, 2014	32.1
32.2	Certification of principal financial officer pursuant to 18 U.S.C. §1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.	10-Q	001-36167	November 10, 2014	32.2
101.INS†	Instance Document
101.SCH†	Scheme Document
101.CAL†	Calculation Linkbase Document
101.DEF†	Definition Linkbase Document
101.LAB†	Labels Linkbase Document
101.PRE†	Presentation Linkbase Document

†XBRL information previously furnished on Karyopharm Therapeutics Inc’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2014, filed with the Securities and Exchange Commission on November 10, 2014.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	KARYOPHARM THERAPEUTICS INC.
Date: November 14, 2014	By:	/s/ Michael Kauffman, M.D., Ph.D.
	Michael Kauffman, M.D., Ph.D.
	Chief Executive Officer
	(Principal executive officer)
Date: November 14, 2014	By:	/s/ Justin A. Renz
	Justin A. Renz
	Executive Vice President and Chief Financial Officer
	(Principal financial and accounting officer)

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EX-31.1

Exhibit 31.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER PURSUANT TO RULE 13a-14(a)/15d-14(a) PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

I, Michael Kauffman, M.D., Ph.D., certify that:

1.             I have reviewed this Quarterly Report on Form 10-Q/A (Amendment No. 1) of Karyopharm Therapeutics Inc.;

2.             Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

/s/ Michael Kauffman, M.D., Ph.D.

Michael Kauffman, M.D., Ph.D.

Chief Executive Officer

(Principal executive officer)

Date: November 14, 2014

EX-31.2

Exhibit 31.2

CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER PURSUANT TO RULE 13a-14(a)/15d-14(a) PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

I, Justin A. Renz, certify that:

1.             I have reviewed this Quarterly Report on Form 10-Q/A (Amendment No. 1) of Karyopharm Therapeutics Inc.;

2.             Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

/s/ Justin A. Renz

Justin A. Renz

Executive Vice President and Chief Financial Officer

(Principal financial and accounting officer)

Date: November 14, 2014