[8-K] Karyopharm Therapeutics Inc. Reports Material Event

Rhea-AI Filing Summary

Karyopharm Therapeutics (KPTI) completed a set of financing transactions. On October 10, 2025, the company entered indentures for 9.00% senior secured convertible notes due 2028 and 2029 and executed related registration rights agreements with term loan lenders.

The company borrowed $12.5 million under its credit and guaranty agreement. It also issued $15.0 million aggregate principal amount of 9.00% senior secured convertible notes due 2028 and $103.5 million aggregate principal amount of 9.00% senior secured convertible notes due 2029. These steps were part of previously announced financing transactions involving term loan lenders, holders of then-outstanding convertible notes, and other investors.

As of October 14, 2025, shares outstanding were 15,926,939, assuming no exercises of pre-funded warrants or warrants and no conversions of the newly issued convertible notes. The filing also includes exhibits for the new indentures, warrant forms, amendments to credit and revenue interest agreements, exchange agreements, a securities purchase agreement, and registration rights agreements.

Insights

Capital structure analyst

KPTI adds 9% secured converts (2028/2029) and borrows $12.5M.

Karyopharm formalized two series of 9.00% senior secured convertible notes—2028 and 2029—and borrowed $12.5 million under its credit agreement. The principal amounts issued were $15.0 million (2028) and $103.5 million (2029), indicating a mix of new issuances alongside related exchange and purchase agreements listed in the exhibits.

These instruments introduce fixed coupon obligations and potential future equity conversion, with specific terms governed by the new indentures and registration rights agreements. As of October 14, 2025, shares outstanding were 15,926,939, a baseline figure for assessing any future conversions.

Key items in the exhibits include the indentures, exchange agreements, amendments to credit and revenue interest agreements, and warrant forms. Actual effects on leverage and equity depend on noteholder actions and subsequent disclosures.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported): October 10, 2025

Karyopharm Therapeutics Inc.

(Exact Name of Registrant as Specified in Charter)

Delaware		001-36167		26-3931704
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification No.)

85 Wells Avenue, 2nd Floor
Newton, Massachusetts		02459
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s telephone number, including area code: (617) 658-0600

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, $0.0001 par value		KPTI		Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement.

On October 10, 2025 (the “Closing Date”), Karyopharm Therapeutics Inc. (the “Company”) closed a series of transactions with its term loan lenders, holders of its then-outstanding convertible notes and other investors, which were previously announced by the Company on October 8, 2025 (collectively, the “Financing Transactions”).

On the Closing Date, the Company entered into (i) an indenture with respect to the Company’s 9.00% convertible senior notes due 2028, dated October 10, 2025, between the Company, the guarantors party thereto and Wilmington Savings Fund Society, FSB (“WSFS”), as trustee and collateral agent, (ii) an indenture with respect to the Company’s 9.00% convertible senior notes due 2029, dated October 10, 2025, between the Company, the guarantors party thereto and WSFS, as trustee and collateral agent and (iii) registration rights agreements, dated October 10, 2025, with each of the term loan lenders, in each case on the terms described in the Current Report on Form 8-K filed by the Company on October 8, 2025.

The representations, warranties and covenants contained in the various agreements and other documents included as exhibits herewith were made solely for the benefit of the parties thereto and may be subject to limitations agreed upon by the contracting parties. Accordingly, these agreements and documents are only to provide investors with information regarding the terms thereof and not to provide investors with any other factual information regarding the Company or its business, and such agreements and documents should be read in conjunction with the disclosures in the Company’s periodic reports and other filings with the Securities and Exchange Commission.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

On the Closing Date and as disclosed in the Current Report on Form 8-K filed by the Company on October 8, 2025, the Company borrowed $12.5 million under its credit and guaranty agreement, as amended, by the First Amendment and Waiver to Credit and Guaranty Agreement dated as of October 7, 2025.

On the Closing Date and as disclosed in the Current Report on Form 8-K filed by the Company on October 8, 2025, the Company issued $15.0 million aggregate principal amount of 9.00% senior secured convertible notes due 2028 and $103.5 million aggregate principal amount of 9.00% senior secured convertible notes due 2029.

Item 8.01 Other Events.

As of October 14, 2025, the Company has 15,926,939 shares of common stock outstanding (assuming no exercise of any outstanding pre-funded warrants or warrants or conversions of any outstanding convertible notes issued in the Financing Transactions).

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.		Description
4.1		Indenture (including form of Note) with respect to the Company’s 9.00% Convertible Senior Notes due 2028, dated October 10, 2025, between the Company, the guarantors party thereto and Wilmington Savings Fund Society, FSB, as trustee and collateral agent
4.2		Indenture (including form of Note) with respect to the Company’s 9.00% Convertible Senior Notes due 2029, dated October 10, 2025, between the Company, the guarantors party thereto and Wilmington Savings Fund Society, FSB, as trustee and collateral agent
4.3		Form of Warrant to Purchase Common Stock
4.4		Form of Warrant to Purchase Common Stock
4.5		Form of Warrant to Purchase Common Stock
4.6		Form of Pre-Funded Warrant to Purchase Common Stock
10.1		First Amendment and Waiver to Credit and Guaranty Agreement, dated October 7, 2025, by and among the Company, as borrower, the lenders party thereto and Wilmington Savings Fund Society, FSB, as administrative agent for the lenders party thereto and collateral agent
10.2		Note Purchase Agreement, dated October 7, 2025, by and among the Company and the other parties thereto
10.3		Form of Exchange Agreement, dated October 7, 2025, by and among the Company and the other parties thereto
10.4		Form of Exchange Agreement, dated October 7, 2025, by and among the Company and the other parties thereto.
10.5		Form of Exchange Agreement, dated October 7, 2025, by and among the Company and the other parties thereto
10.6		Sixth Amendment to the Revenue Interest Financing Agreement, dated October 7, 2025, by and among the Company and the investors party thereto, HealthCare Royalty Management, LLC as the investor representative, and HCR Karyopharm SPV, LLC, as the collateral agent
10.7		Securities Purchase Agreement, dated October 7, 2025, by and among the Company and the other parties thereto
10.8		Form of Registration Rights Agreement, dated October 10, 2025, by and among the Company and the other parties thereto
10.9		Registration Rights Agreement, dated October 7, 2025, by and among the Company and the other parties thereto
104		Cover Page Interactive Data File (embedded within the iXBRL document).

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 hereunto duly authorized.

				KARYOPHARM THERAPEUTICS INC.
Date: October 14, 2025				By:		/s/ Michael Mano
						Michael Mano
						Senior Vice President, General Counsel and Secretary

FAQ

What financing steps did Karyopharm (KPTI) complete on October 10, 2025?

Karyopharm entered indentures for 9.00% senior secured convertible notes due 2028 and 2029 and executed registration rights agreements with term loan lenders.

How much did Karyopharm (KPTI) borrow under its credit agreement?

The company borrowed $12.5 million under its credit and guaranty agreement.

What principal amounts of convertible notes did Karyopharm (KPTI) issue?

Karyopharm issued $15.0 million of 9.00% senior secured convertible notes due 2028 and $103.5 million due 2029.

What is the coupon on Karyopharm’s new convertible notes?

Both series carry a 9.00% coupon.

How many Karyopharm (KPTI) shares were outstanding after these transactions?

As of October 14, 2025, shares outstanding were 15,926,939, assuming no warrant exercises and no note conversions.

What agreements were filed as exhibits related to these transactions?

Exhibits include the note indentures, warrant forms, a first amendment and waiver to the credit agreement, exchange agreements, a securities purchase agreement, a sixth amendment to the revenue interest financing agreement, and registration rights agreements.