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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

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

For the quarterly period ended September 30, 2025

☐ TRANSITION 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)

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 (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 ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted 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 such files). Yes ☒ No ☐

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


Large accelerated filer	☐	Accelerated filer	☒

Non-accelerated filer	☐	Smaller reporting company	☒

		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. ☐

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

As of October 30, 2025, there were 17,050,876 shares of Common Stock, $0.0001 par value per share, outstanding.

Table of Contents

TABLE OF CONTENTS


	PART I - FINANCIAL INFORMATION	2

Item 1.	Condensed Consolidated Financial Statements (Unaudited)	2
	Condensed Consolidated Balance Sheets	2
	Condensed Consolidated Statements of Operations	3
	Condensed Consolidated Statements of Comprehensive Income (Loss)	4
	Condensed Consolidated Statements of Cash Flows	5
	Condensed Consolidated Statements of Stockholders’ Deficit	6
	Notes to Condensed Consolidated Financial Statements	7
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	23
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	33
Item 4.	Controls and Procedures	33

	PART II - OTHER INFORMATION	34

Item 1A.	Risk Factors	34
Item 5.	Other Information	86
Item 6.	Exhibits	87
	Signatures	89

Table of Contents

PART I - FINANCIAL INFORMATION

Item 1. Condensed Consolidated Financial Statements (Unaudited).

KARYOPHARM THERAPEUTICS INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(unaudited)

(in thousands, except per share amounts)


	September 30, 2025			December 31, 2024
Assets
Current assets:
Cash and cash equivalents	$	37,672		$	62,476
Investments		8,205			46,236
Accounts receivable, net		31,877			30,766
Inventory		3,966			4,739
Prepaid expenses and other current assets		8,026			12,245
Total current assets		89,746			156,462
Property and equipment, net		122			400
Operating lease right-of-use assets		4,680			5,884
Restricted cash		350			338
Other assets		1,334			1,334
Total assets	$	96,232		$	164,418
Liabilities and stockholders’ deficit
Current liabilities:
Accounts payable	$	5,392		$	5,107
Accrued expenses		66,328			60,652
Convertible senior notes due 2025		250			24,426
Senior secured term loan		12,500			—
Operating lease liabilities		922			438
Other current liabilities		1,765			1,641
Total current liabilities		87,157			92,264
Convertible senior notes due 2029		68,602			68,345
Convertible senior notes due 2025, net of current portion		24,246			—
Senior secured term loan, net of current portion		83,895			94,603
Deferred royalty obligation		73,499			73,499
Common stock warrants		7,965			12,582
Operating lease liabilities, net of current portion		6,008			6,712
Other liabilities		14,118			2,430
Total liabilities		365,490			350,435
Stockholders’ deficit:
Preferred stock, $0.0001 par value; 5,000 shares authorized; none issued and outstanding		—			—
Common stock, $0.0001 par value; 53,333 shares authorized; 8,702 and 8,413 shares issued and outstanding as of September 30, 2025 and December 31, 2024, respectively		13			13
Additional paid-in capital		1,388,289			1,377,786
Accumulated other comprehensive loss		(259	)		(356	)
Accumulated deficit		(1,657,301	)		(1,563,460	)
Total stockholders’ deficit		(269,258	)		(186,017	)
Total liabilities and stockholders’ deficit	$	96,232		$	164,418

See accompanying notes to condensed consolidated financial statements.

Table of Contents

KARYOPHARM THERAPEUTICS INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(unaudited)

(in thousands, except per share amounts)


	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	2025			2024			2025			2024
Revenues:
Product revenue, net	$	32,032		$	29,516		$	82,767		$	83,554
License and other revenue		12,012			9,267			29,221			31,141
Total revenue		44,044			38,783			111,988			114,695
Operating expenses:
Cost of sales		2,113			1,300			4,465			4,676
Research and development		30,544			36,134			97,950			109,930
Selling, general and administrative		26,607			27,632			82,436			88,251
Total operating expenses		59,264			65,066			184,851			202,857
Loss from operations		(15,220	)		(26,283	)		(72,863	)		(88,162	)
Other income (expense):
Interest income		553			1,832			2,166			5,918
Interest expense		(11,008	)		(11,385	)		(33,230	)		(26,218	)
Gain on extinguishment of debt		—			—			—			44,702
Other (expense) income, net		(7,418	)		3,792			10,196			18,284
Total other (expense) income, net		(17,873	)		(5,761	)		(20,868	)		42,686
Loss before income taxes		(33,093	)		(32,044	)		(93,731	)		(45,476	)
Income tax provision		(34	)		(28	)		(110	)		(166	)
Net loss	$	(33,127	)	$	(32,072	)	$	(93,841	)	$	(45,642	)
Basic net loss per share	$	(3.82	)	$	(3.85	)	$	(10.93	)	$	(5.68	)
Diluted net loss per share (Note 7)	$	(3.82	)	$	(3.85	)	$	(10.93	)	$	(10.40	)
Weighted-average number of common shares outstanding used to compute basic net loss per share		8,669			8,336			8,587			8,036
Weighted-average number of common shares outstanding used to compute diluted net loss per share		8,669			8,336			8,587			8,442

See accompanying notes to condensed consolidated financial statements.

Table of Contents

KARYOPHARM THERAPEUTICS INC.

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)

(unaudited)

(in thousands)


	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	2025			2024			2025			2024
Net loss	$	(33,127	)	$	(32,072	)	$	(93,841	)	$	(45,642	)
Other comprehensive (loss) income
Unrealized (loss) gain on investments		(7	)		291			(53	)		242
Foreign currency translation adjustment		(1	)		92			150			(303	)
Comprehensive loss	$	(33,135	)	$	(31,689	)	$	(93,744	)	$	(45,703	)

See accompanying notes to condensed consolidated financial statements.

Table of Contents

KARYOPHARM THERAPEUTICS INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(unaudited)

(in thousands)


	For the Nine Months Ended September 30,
	2025			2024
Operating activities
Net loss	$	(93,841	)	$	(45,642	)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense		10,147			14,562
Depreciation and amortization		277			259
Amortization of debt issuance costs and discounts		8,101			4,012
Net amortization of premiums and discounts on investments		(401	)		(2,112	)
Gain on extinguishment of debt		—			(44,702	)
Change in fair value of embedded derivatives and common stock warrants		(10,596	)		(18,343	)
Changes in operating assets and liabilities:
Accounts receivable, net		(1,111	)		(4,816	)
Inventory		773			(1,629	)
Prepaid expenses and other assets		4,219			(2,933	)
Operating lease right-of-use assets		1,204			1,690
Accounts payable		285			2,660
Accrued expenses and other liabilities		17,622			(2,253	)
Operating lease liabilities		(220	)		(2,429	)
Net cash used in operating activities		(63,541	)		(101,676	)
Investing activities
Proceeds from maturities of investments		38,378			138,187
Purchases of investments		—			(57,316	)
Purchases of property and equipment		—			(195	)
Net cash provided by investing activities		38,378			80,676
Financing activities
Proceeds from issuance of senior secured term loan		—			83,300
Proceeds from the exercise of stock options and shares issued under the employee stock purchase plan		356			772
Payment of debt issuance costs		—			(2,588	)
Payment of deferred royalty obligation		—			(40,518	)
Net cash provided by financing activities		356			40,966
Effect of exchange rates on cash, cash equivalents and restricted cash		15			9
Net (decrease) increase in cash, cash equivalents and restricted cash		(24,792	)		19,975
Cash, cash equivalents and restricted cash at beginning of period		62,814			53,192
Cash, cash equivalents and restricted cash at end of period	$	38,022		$	73,167
Reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets
Cash and cash equivalents	$	37,672		$	72,828
Short-term restricted cash		—			33
Long-term restricted cash		350			306
Total cash, cash equivalents and restricted cash	$	38,022		$	73,167
Supplemental disclosures:
Cash paid for interest on deferred royalty obligation	$	3,711		$	18,926
Cash paid for interest on convertible debt and term loan	$	10,668		$	11,472
Cash paid for amounts included in the measurement of operating lease liabilities	$	1,023		$	2,844
Convertible senior notes due 2029 issued with warrants to purchase 3,100 shares of common stock in exchange for a $148,000 reduction of convertible senior notes due 2025	$	—		$	111,000
Senior secured term loan issued in exchange for a $14,700 reduction of deferred royalty obligation	$	—		$	15,000
Issuance of common stock used to settle a financial advisory fee related to financing activities	$	—		$	7,697
Convertible senior notes due 2029 issued in exchange for a $5,000 reduction of deferred royalty obligation	$	—		$	5,000

See accompanying notes to condensed consolidated financial statements.

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KARYOPHARM THERAPEUTICS INC.

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ DEFICIT

(unaudited)

(in thousands)


	Common Shares				Additional Paid-In Capital		Accumulated Other Comprehensive (Loss) Income			Accumulated Deficit			Total Stockholders’ Deficit
	Shares		Amount
Balance as of June 30, 2025		8,647	$	13	$	1,385,486	$	(251	)	$	(1,624,174	)	$	(238,926	)
Vesting of restricted stock		55		—		—		—			—			—
Stock-based compensation		—		—		2,803		—			—			2,803
Unrealized loss on investments		—		—		—		(7	)		—			(7	)
Foreign currency cumulative translation adjustment		—		—		—		(1	)		—			(1	)
Net loss		—		—		—		—			(33,127	)		(33,127	)
Balance as of September 30, 2025		8,702	$	13	$	1,388,289	$	(259	)	$	(1,657,301	)	$	(269,258	)

Balance as of June 30, 2024		8,309	$	13	$	1,369,060	$	(605	)	$	(1,500,608	)	$	(132,140	)
Vesting of restricted stock		45		—		—		—			—			—
Stock-based compensation		—		—		4,182		—			—			4,182
Unrealized gain on investments		—		—		—		291			—			291
Foreign currency cumulative translation adjustment		—		—		—		92			—			92
Net loss		—		—		—		—			(32,072	)		(32,072	)
Balance as of September 30, 2024		8,354	$	13	$	1,373,242	$	(222	)	$	(1,532,680	)	$	(159,647	)

Balance as of December 31, 2024		8,413	$	13	$	1,377,786	$	(356	)	$	(1,563,460	)	$	(186,017	)
Vesting of restricted stock		227		—		—		—			—			—
Shares issued under the employee stock purchase plan		62		—		356		—			—			356
Stock-based compensation		—		—		10,147		—			—			10,147
Unrealized loss on investments		—		—		—		(53	)		—			(53	)
Foreign currency cumulative translation adjustment		—		—		—		150			—			150
Net loss		—		—		—		—			(93,841	)		(93,841	)
Balance as of September 30, 2025		8,702	$	13	$	1,388,289	$	(259	)	$	(1,657,301	)	$	(269,258	)

Balance as of December 31, 2023		7,661	$	12	$	1,350,981	$	(161	)	$	(1,487,038	)	$	(136,206	)
Vesting of restricted stock		158		—		—		—			—			—
Shares issued under the employee stock purchase plan		77		—		772		—			—			772
Issuance of common stock for financial advisory fee		458		1		6,927		—			—			6,928
Stock-based compensation		—		—		14,562		—			—			14,562
Unrealized gain on investments		—		—		—		242			—			242
Foreign currency cumulative translation adjustment		—		—		—		(303	)		—			(303	)
Net loss		—		—		—		—			(45,642	)		(45,642	)
Balance as of September 30, 2024		8,354	$	13	$	1,373,242	$	(222	)	$	(1,532,680	)	$	(159,647	)

See accompanying notes to condensed consolidated financial statements.

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KARYOPHARM THERAPEUTICS INC.

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

1. Nature of Business, Basis of Presentation and Segment Information

Nature of Business

Karyopharm Therapeutics Inc., a Delaware corporation (collectively with its subsidiaries, the “Company,” “we,” “us,” or “our”), is a commercial-stage pharmaceutical company pioneering novel cancer therapies and dedicated to the discovery, development and commercialization of first-in-class drugs directed against nuclear export for the treatment of cancer. We were incorporated in Delaware on December 22, 2008 and have a principal place of business in Newton, Massachusetts.

Our scientific expertise is based upon an understanding of the regulation of intracellular communication between the nucleus and the cytoplasm. We have discovered and are developing and commercializing novel, small molecule Selective Inhibitor of Nuclear Export compounds that inhibit the nuclear export protein exportin 1. Our primary focus is on marketing XPOVIO®(selinexor) in its currently approved indications, as well as developing and seeking the regulatory approval of selinexor as an oral agent targeting multiple high unmet cancer indications, including our lead clinical programs in myelofibrosis and our other late-stage clinical programs in endometrial cancer and multiple myeloma.

Our lead asset, XPOVIO, received its initial U.S. approval from the U.S. Food and Drug Administration in July 2019 and is currently approved and marketed for the following indications: (i) in combination with bortezomib and dexamethasone for the treatment of adult patients with multiple myeloma who have received at least one prior therapy; (ii) in combination with dexamethasone for the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least four prior therapies and whose disease is refractory to at least two proteasome inhibitors, at least two immunomodulatory agents, and an anti-CD38 monoclonal antibody; and (iii) for the treatment of adult patients with relapsed or refractory diffuse large B-cell lymphoma (“DLBCL”), not otherwise specified, including DLBCL arising from follicular lymphoma, after at least two lines of systemic therapy. The commercialization of XPOVIO and NEXPOVIO® (selinexor) (the brand name for selinexor in Europe and the United Kingdom) outside of the U.S. is managed by our partners in their respective territories. XPOVIO/NEXPOVIO has received regulatory approval in various indications in 50 countries outside of the U.S. and is commercially available in a growing number of countries as our partners continue to secure reimbursement approvals.

Liquidity, Capital Resources and Going Concern

We have historically financed our operations primarily through a combination of proceeds from (i) product revenue sales; (ii) public and private placements of equity securities; (iii) the issuance of convertible debt; (iv) a term loan; (v) our deferred royalty obligation; (vi) at the market offerings; and (vii) business development activities. As of September 30, 2025, we had $45.9 million of cash, cash equivalents and investments and an accumulated deficit of $1.7 billion. We have incurred significant operating losses since our inception and we anticipate that we will continue to incur significant operating losses to maintain our research and development programs, including as we continue to develop and seek regulatory approval of selinexor for multiple cancer indications, and to support our continued operations. As a result, our continued operations are dependent on our ability to raise additional funding or enter in other strategic alternatives and marketing XPOVIO in its currently approved indications. Based on our current business plan and current capital resources, given the uncertainty regarding the availability of additional funding or other strategic alternatives and considering our debt service obligations, and the financial covenant to maintain minimum liquidity, we have concluded that there is substantial doubt regarding our ability to continue as a going concern within one year after the date the accompanying condensed consolidated financial statements are issued. We plan to address the conditions that raise substantial doubt regarding our ability to continue as a going concern by, among other things, obtaining additional funding through equity offerings, debt financings and refinancings, collaborations, strategic alliances and/or licensing arrangements. However, there is no assurance that these efforts will result in additional funding, strategic alliances or licensing arrangements or sufficiently address the Company’s ability to continue as a going concern. Refer to Note 12, “Subsequent Event” for a description of transactions that occurred in October 2025 that partially address the conditions that raise substantial doubt regarding our ability to continue as a going concern.

If we utilize our capital resources more quickly than anticipated or are unable to obtain additional funding or engage in strategic alternatives, we may have to significantly curtail, delay, reduce or eliminate one or more of our research and development programs or any current or future commercialization efforts for one or more of our products or product candidates, which could materially adversely affect our business, financial condition, and results of operations. We may determine to take additional actions to reduce our spending in the near term. As we announced on July 11, 2025, we reduced our workforce by approximately 20% as part of our ongoing careful management of operating expenses. If we are unable to continue as a going concern, we may have to liquidate assets and may receive less than the value at which those assets are carried on our financial statements. We may also determine to cease operations or file for bankruptcy protection. In any of these circumstances, it is likely that investors will lose all or part of their

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investment. If there remains substantial doubt about our ability to continue as a going concern, investors or other financing sources may be unwilling to provide funding to us on commercially reasonable terms, if at all. The accompanying condensed consolidated financial statements do not include any adjustments to the carrying amounts and classification of assets and liabilities that may be necessary if we were unable to continue as a going concern.

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial reporting and as required by Regulation S-X, Rule 8-03. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In our opinion, all adjustments (including those which are normal and recurring) considered necessary for a fair presentation of the interim financial information have been included. When preparing financial statements in conformity with GAAP, we must make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and related disclosures at the date of the financial statements. Actual results could differ from those estimates. Additionally, operating results for the three and nine months ended September 30, 2025 are not necessarily indicative of the results that may be expected for any other interim period or for the fiscal year ending December 31, 2025. For further information, refer to the financial statements and footnotes included in our Annual Report on Form 10-K for the year ended December 31, 2024 as filed with the Securities and Exchange Commission on February 19, 2025 (“Annual Report”).

On February 25, 2025, we effected a 1-for-15 reverse stock split of our common stock (the “Reverse Stock Split”). All share and per share amounts in these condensed consolidated financial statements and notes thereto, including the conversion rates of convertible debt and the exercise price of common stock warrants, have been adjusted retroactively to reflect the Reverse Stock Split for all periods presented.

Basis of Consolidation

The condensed consolidated financial statements as of September 30, 2025 include the accounts of Karyopharm Therapeutics Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

The significant accounting policies used in preparation of these condensed consolidated financial statements in this Form 10-Q are consistent with those discussed in Note 2, “Summary of Significant Accounting Policies,” in our Annual Report.

Segment Information

Operating segments are defined as components of an enterprise whose operating results are regularly reviewed by the Chief Operating Decision Maker (“CODM”) to allocate resources and assess performance. We view our operations and manage our business as a single operating segment, which is the business of discovering, developing and commercializing drugs to treat cancer. All our revenue and all our long-lived assets are attributable to our single operating segment and to Karyopharm Therapeutics Inc., which is domiciled in the United States.

Our CODM is our Chief Executive Officer who uses net loss as reported on the condensed consolidated statements of operations to monitor budget versus actual results and to ensure we have sufficient capital resources to develop and seek regulatory approval of our product candidates. The following table presents the significant revenue and expense categories (in thousands) in our single operating segment:

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	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	2025			2024			2025			2024
Revenue from external customers	$	44,044		$	38,783		$	111,988		$	114,695
Cost of sales (1)		(2,082	)		(1,239	)		(4,352	)		(4,499	)
Research and development expenses (2)		(30,743	)		(36,395	)		(99,942	)		(110,722	)
Commercial expenses (2)		(11,112	)		(12,440	)		(35,776	)		(38,606	)
General and administrative expenses (2)		(12,524	)		(10,810	)		(34,634	)		(34,468	)
Other segment (expenses) income (3)		(20,710	)		(9,971	)		(31,125	)		27,958
Net loss of our single operating segment	$	(33,127	)	$	(32,072	)	$	(93,841	)	$	(45,642	)

(1) Excludes stock-based compensation expense
(2) Excludes stock-based compensation expense and the effects of certain allocations of certain expenses
(3) Includes total other income (expense), net and income tax provision on the condensed consolidated statements of operations and stock-based compensation expense

2. Product Revenue

To date, our only source of product revenue has been from the U.S. sales of XPOVIO. Net product revenue, including provisions primarily consisting of distribution fees and cash discounts, as well as reserves for chargebacks, rebates and returns, were as follows (in thousands):


	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	2025			2024			2025			2024
Gross product revenue	$	44,163		$	43,031		$	122,992		$	119,457
Provisions for product revenue		(12,131	)		(13,515	)		(40,225	)		(35,903	)
Total product revenue, net	$	32,032		$	29,516		$	82,767		$	83,554

As of September 30, 2025 and December 31, 2024, net product revenue of $26.5 million and $27.8 million, respectively, were included in accounts receivable. To date, we have had no bad debt write-offs and we do not currently have credit issues with any customers. There were no credit losses associated with accounts receivable as of September 30, 2025 and December 31, 2024.

3. Inventory

The following table presents our inventory (in thousands), all of which was related to XPOVIO:


	As of September 30, 2025		As of December 31, 2024
Raw materials	$	630	$	720
Work in process		2,903		3,542
Finished goods		433		477
Total inventory	$	3,966	$	4,739

4. License Agreements

In prior periods, we entered into license agreements with Berlin-Chemie AG, an affiliate of the Menarini Group (“Menarini”), and Antengene Therapeutics Limited (“Antengene”), both of which are accounted for within the scope of Accounting Standards Codification 606, Revenue from Contracts with Customers. For further details on the terms and accounting treatment considerations for these contracts, please refer to Note 5, “License and Asset Purchase Agreements,” to our consolidated financial statements contained in Item 8 of our Annual Report.

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The following table presents information about our license and other revenue (in thousands):


	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
	2025		2024		2025		2024
Menarini	$	11,142	$	8,753	$	26,960	$	27,232
Antengene		670		273		1,811		1,272
Other		200		241		450		2,637
Total license and other revenue	$	12,012	$	9,267	$	29,221	$	31,141

During the three months ended September 30, 2025, we recognized $8.2 million of milestone revenue, $1.5 million of revenue for the reimbursement of development-related expenses and $1.0 million of royalty revenue from Menarini. We also recognized $0.5 million of royalty revenue from Antengene and $0.2 million of other revenue.

During the three months ended September 30, 2024, we recognized $6.0 million of milestone revenue, $2.0 million of revenue for the reimbursement of development-related expenses, $0.5 million of royalty revenue from Menarini, and $0.2 million of other revenue.

During the nine months ended September 30, 2025, we recognized $15.0 million of revenue for the reimbursement of development-related expenses, $8.2 million of milestone revenue, and $2.9 million of royalty revenue from Menarini. We also recognized $1.6 million of royalty revenue from Antengene and $0.5 million of other revenue.

During the nine months ended September 30, 2024, we recognized $15.0 million of revenue for the reimbursement of development-related expenses, $10.0 million of milestone revenue, $1.6 million of royalty revenue, and $0.6 million of other revenue from Menarini. We also recognized $1.2 million of royalty revenue from Antengene and $2.0 million of other milestone-related revenue.

License and other revenue of $5.3 million and $2.9 million were included in accounts receivable as of September 30, 2025 and December 31, 2024, respectively.

5. Fair Value Measurements

Financial instruments, including cash, cash equivalents, accounts receivable, net, other current assets, other assets, restricted cash, accounts payable, and accrued expenses, are presented at amounts that approximate fair value as of September 30, 2025 and December 31, 2024.

Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. We disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. The fair value hierarchy prioritizes valuation inputs based on the observable nature of those inputs. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value and is not a measure of credit quality. The hierarchy defines three levels of valuation inputs:

Level 1 - Quoted prices in active markets for identical assets or liabilities

Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly

Level 3 - Unobservable inputs that reflect the assumptions market participants would use in pricing the asset or liability

Items classified as Level 2 consist of corporate debt securities, commercial paper and U.S. government and agency securities. We estimate the fair value of these marketable securities by taking into consideration valuations obtained from third-party pricing sources. These pricing sources utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include market pricing based on real-time trade data for the same or similar securities, issuer credit spreads, benchmark yields, and other observable inputs. We validate the prices provided by our third-party pricing sources by understanding the models used, obtaining market values from other pricing sources and analyzing pricing data in certain instances.

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The following tables present information about our financial assets that have been measured at fair value and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands):


	As of September 30, 2025		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents:
Money market funds	$	21,822	$	21,822	$	—	$	—
U.S. government and agency securities		5,313		—		5,313		—
Investments:
Corporate debt securities		8,205		—		8,205		—
	$	35,340	$	21,822	$	13,518	$	—


	As of December 31, 2024		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents:
Money market funds	$	46,990	$	46,990	$	—	$	—
Commercial paper		5,072		—		5,072		—
Investments:
Corporate debt securities		39,091		—		39,091		—
Commercial paper		3,166		—		3,166		—
U.S. government and agency securities		3,979		—		3,979		—
	$	98,298	$	46,990	$	51,308	$	—

In certain cases where there is limited activity or less transparency around inputs to valuation, the related assets or liabilities are classified as Level 3. The following liabilities are measured at fair value at the end of each reporting period, with changes in fair value recognized as a component of other (expense) income, net on our condensed consolidated statements of operations. See Note 10, “Long-Term Obligations” to our condensed consolidated financial statements for further discussion of these liabilities:

(1)

The embedded derivative liabilities (the “2029 Notes Derivatives”) associated with the 2029 Notes are included as a component of the 2029 Notes on our condensed consolidated balance sheets. The valuation method for the 2029 Notes Derivatives incorporates certain unobservable Level 3 key inputs including: (i) the volatility of our common stock price and (ii) our estimated credit spread.

(2)

The warrants to purchase up to 3.1 million shares of our common stock issued in May 2024 (the “May 2024 Warrants”) are classified as a long-term liability on our condensed consolidated balance sheets. The valuation method for the May 2024 Warrants incorporates certain unobservable Level 3 key inputs including: (i) the volatility of our common stock price and (ii) an estimate of when the May 2024 Warrants will be exercised based on an option pricing model.

The following table sets forth a summary of the changes in the estimated fair value of these liabilities, which are all classified as Level 3 (in thousands):


	2029 Notes Derivatives			May 2024 Warrants
Balance as of December 31, 2024	$	13,688		$	12,582
Change in fair value		(5,979	)		(4,617	)
Balance as of September 30, 2025	$	7,709		$	7,965

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6. Investments

The following tables summarize our investments, which are classified as available-for-sale and recorded at fair value (in thousands):


	As of September 30, 2025
	Amortized Cost		Total Unrealized Gains		Total Unrealized Losses		Aggregate Fair Value
Corporate debt securities	$	8,193	$	12	$	—	$	8,205


	As of December 31, 2024
	Amortized Cost		Total Unrealized Gains		Total Unrealized Losses			Aggregate Fair Value
Corporate debt securities	$	39,027	$	66	$	(2	)	$	39,091
Commercial paper		3,165		1		—			3,166
U.S. government and agency securities		3,978		1		—			3,979
Total	$	46,170	$	68	$	(2	)	$	46,236

We determine the appropriate classification of our investments at the time of purchase. All of our investments are reported as short-term as they are available for use during the normal cycle of business. We review any investment when its fair value is less than its amortized cost and when evidence indicates that the investment’s carrying amount is not recoverable within a reasonable period. We evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the investment is compared to its amortized cost basis. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded on our condensed consolidated balance sheet, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that is not related to a credit loss is recognized in other comprehensive (loss) income.

Changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense. Losses are charged against the allowance when we believe the uncollectability of an investment is confirmed or when either of the criteria regarding intent or requirement to sell is met. We do not intend to sell the investments before recovery of their amortized cost bases, which may be at maturity. All of our investments mature within one year from September 30, 2025.

We did not hold any investments that were in an unrealized loss position as of September 30, 2025. We held five investments that were in an unrealized loss position as of December 31, 2024. The unrealized losses were caused by changes to interest rates and do not represent credit losses. The following table summarizes our investments in an unrealized loss position as of December 31, 2024 for which an allowance for credit losses has not been recorded, aggregated by investment type and length of time in a continuous unrealized loss position (in thousands):


	As of December 31, 2024
	Less than 12 Months					12 Months or Longer				Total
	Aggregate Related Fair Value		Unrealized Losses			Aggregate Related Fair Value		Unrealized Losses		Aggregate Related Fair Value		Unrealized Losses
Corporate debt securities	$	4,456	$	(2	)	$	—	$	—	$	4,456	$	(2	)
Commercial paper		1,175		—			—		—		1,175		—
Total	$	5,631	$	(2	)	$	—	$	—	$	5,631	$	(2	)

7. Net Loss Per Share

Basic net loss per common share is calculated using the two-class method by dividing the net loss allocated to common shares by the weighted-average number of common shares outstanding for the period. Diluted net loss per common share is calculated by adjusting net loss to remove the effects from potential dilutive common shares and dividing this adjusted amount by the weighted average number of common shares and potential dilutive common shares outstanding for the period. Potential dilutive common shares are not included if their effect is anti-dilutive.

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As discussed further in Note 10, “Long-Term Obligations”, we have the option to settle the conversion obligation for our 2025 Notes and 2029 Notes in cash, shares or any combination of the two. The 2029 Notes did not impact dilutive loss per common share during the three and nine months ended September 30, 2025 and 2024 because they were anti-dilutive in these periods. The 2025 Notes did not impact dilutive loss per common share during the three and nine months ended September 30, 2025 and for the three months ended September 30, 2024 because they were anti-dilutive in these periods. See the table below for the impact of the 2025 Notes on dilutive loss per common share during the nine months ended September 30, 2024.

As discussed further in Note 11, “Common Share Warrants”, warrants to purchase up to 3.7 million shares of our common stock were outstanding as of September 30, 2025. These warrants are not included in the calculation of basic net loss per share because the warrant holders do not have an obligation to share in our losses. These warrants did not impact dilutive loss per common share during the three and nine months ended September 30, 2025 and 2024 because they were anti-dilutive in these periods.

The following is a reconciliation of the numerator and denominator used to calculate basic and diluted net loss per common share for the nine months ended September 30, 2024 (in thousands except per share amounts):


	For the Nine Months Ended September 30, 2024
Net loss	$	(45,642	)
Add back interest expense on the 2025 Notes		2,518
Add back gain on extinguishment of debt		(44,702	)
Numerator for diluted net loss per common share (A)	$	(87,826	)
Weighted-average number of common shares outstanding		8,036
Dilutive effect of 2025 Notes calculated using the if-converted method		406
Denominator for diluted net loss per common share (B)		8,442
Diluted net loss per common share (= A / B)	$	(10.40	)

In addition to the financial instruments discussed above, the following other potentially dilutive securities were excluded from the calculation of diluted net loss per common share due to their anti-dilutive effect under the treasury method (in thousands):


	As of September 30,
	2025		2024
Outstanding stock options		492		423
Unvested restricted stock units		688		861

8. Stock-based Compensation Expense

The following table summarizes stock-based compensation expense included in operating expenses (in thousands):


	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
	2025		2024		2025		2024
Cost of sales	$	31	$	61	$	113	$	177
Research and development		967		1,062		3,064		3,775
Selling, general and administrative		1,805		3,059		6,970		10,610
Total	$	2,803	$	4,182	$	10,147	$	14,562

Our 2022 Equity Incentive Plan, as amended (the “2022 Plan”), provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards and other stock-based awards. On May 28, 2025, our stockholders approved an amendment to the 2022 Plan to increase the number of shares of our common stock available for issuance under the 2022 Plan by 450,000 shares.

9. Stockholders’ Equity

On February 17, 2023, we entered into an Open Market Sale Agreement (the “2023 Open Market Sale Agreement”) with Jefferies LLC, as agent (“Jefferies”). Under the 2023 Open Market Sale Agreement, we may issue and sell shares of our common stock having an aggregate offering price of up to $100.0 million (the “Shares”) from time to time through Jefferies (the “2023 Open Market Offering”).

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Under the 2023 Open Market Sale Agreement, Jefferies may sell the Shares by methods deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended (the “Securities Act”). We may sell the Shares in amounts and at times to be determined by us from time to time subject to the terms and conditions of the 2023 Open Market Sale Agreement, but we have no obligation to sell any of the Shares in the 2023 Open Market Offering.

We or Jefferies may suspend or terminate the offering of Shares upon notice to the other party and subject to other conditions. We have agreed to pay Jefferies commissions for its services in acting as agent in the sale of the Shares in the amount of up to 3.00% of gross proceeds from the sale of the Shares pursuant to the 2023 Open Market Sale Agreement. We have also agreed to provide Jefferies with customary indemnification and contribution rights.

We did not sell any Shares under the 2023 Open Market Sale Agreement during the three and nine months ended September 30, 2025 and 2024. As of September 30, 2025, $100.0 million of Shares were available for issuance and sale under the 2023 Open Market Sale Agreement.

On January 30, 2025, our stockholders approved an amendment to our Restated Certificate of Incorporation, as amended, to increase the number of authorized shares of our capital stock from 405,000,000 shares to 805,000,000 shares and the number of authorized shares of our common stock from 400,000,000 shares to 800,000,000 shares. In addition, on January 30, 2025, our stockholders approved an amendment to our Restated Certificate of Incorporation, as amended, to effect a reverse stock split of our issued and outstanding shares of common stock within a range of not less than 1-for-5 and not greater 1-for-15, and a proportionate reduction in the number of authorized shares of common stock, with the exact ratio within such range and the implementation and timing of such reverse stock split subsequently determined at the sole discretion of our board of directors, without further approval or authorization of our stockholders.

On February 25, 2025, we effected a 1-for-15 reverse stock split of the issued and outstanding shares of our common stock. The Reverse Stock Split proportionally reduced the number of authorized shares of our common stock from 800,000,000 shares to 53,333,333 shares. The Reverse Stock Split did not change the par value of our common stock. In addition, proportionate adjustments were made to the number of shares of common stock available for issuance under our equity incentive plans; the number of shares underlying, and the exercise prices of, outstanding equity awards under such plans and outstanding warrants; and the conversion rates of outstanding convertible notes.

10. Long-Term Obligations

2025 Notes

In October 2018, we issued $172.5 million aggregate principal amount of the 2025 Notes in a private offering to qualified institutional buyers in reliance on Rule 144A under the Securities Act. In connection with the issuance of the 2025 Notes, we incurred $5.6 million of debt issuance costs, which were amortized to interest expense using the effective interest method over seven years. In May 2024, we exchanged $148.0 million aggregate principal amount of our 2025 Notes for (i) $111.0 million aggregate principal amount of our 2029 Notes and (ii) the May 2024 Warrants to purchase up to 3.1 million shares of our common stock. The 2029 Notes and the May 2024 Warrants are described in more detail below. $24.5 million in aggregate principal amount of the 2025 Notes remained outstanding following completion of the May 2024 exchange transactions and such amount was outstanding as of September 30, 2025.

The 2025 Notes are senior unsecured obligations and bear interest at a rate of 3.00% per year payable semiannually in arrears on April 15 and October 15 of each year. Upon conversion, the 2025 Notes will be converted into cash, shares of our common stock, or a combination of cash and shares of our common stock, at our election. The 2025 Notes are subject to redemption at our option, in whole or in part, if the conditions described below are satisfied. Holders may require us to repurchase their 2025 Notes following a fundamental change (as defined within the indenture governing the 2025 Notes) at a cash repurchase price generally equal to the principal amount of the 2025 Notes to be repurchased, plus accrued and unpaid interest. The 2025 Notes will mature on October 15, 2025, unless earlier converted, redeemed or repurchased in accordance with their terms. Following July 15, 2025 and at any time prior to the close of business on October 13, 2025, holders may convert the 2025 Notes at an initial conversion rate of 4.2049 shares of common stock per $1,000 principal amount of the 2025 Notes (equivalent to an initial conversion price of approximately $237.82 per share of common stock) in multiples of $1,000 principal amount. None of the 2025 Notes were converted as of September 30, 2025.

We may redeem for cash all or part of the 2025 Notes at our option if the last reported sale price of our common stock equals or exceeds 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending within five trading days prior to the date on which we send any notice of redemption. The redemption price will be 100% of the principal amount of the 2025 Notes to be redeemed, plus accrued and unpaid interest, if any. In addition, calling any convertible note for redemption will constitute a make-whole fundamental change with respect to that convertible

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note, in which case the conversion rate applicable to the conversion of that convertible note, if it is converted in connection with the redemption, will be increased in certain circumstances. We did not redeem any of the 2025 Notes as of September 30, 2025.

The outstanding balances of the 2025 Notes consisted of the following (in thousands):


	As of September 30, 2025			As of December 31, 2024
Principal	$	24,500		$	24,500
Less: unamortized debt issuance costs		(4	)		(74	)
2025 Notes	$	24,496		$	24,426

We determined the expected life of the 2025 Notes was equal to its seven-year term and the effective interest rate was 3.53%. As of September 30, 2025, the “if-converted value” did not exceed the remaining principal amount of the 2025 Notes. The fair value of the 2025 Notes is influenced by market interest rates, our stock price and stock price volatility, and has been classified as Level 2 within the fair value hierarchy as it uses quoted prices in active markets. The estimated fair value of the 2025 Notes as of September 30, 2025 and December 31, 2024 was approximately $22.7 million and $19.1 million, respectively.

The following table sets forth total interest expense recognized related to the 2025 Notes (in thousands):


	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
	2025		2024		2025		2024
Contractual interest expense	$	184	$	184	$	552	$	2,170
Amortization of debt issuance costs		12		33		70		348
Total interest expense	$	196	$	217	$	622	$	2,518

Future minimum payments on the 2025 Notes as of September 30, 2025 were as follows (in thousands):


	Future Minimum Payments
Minimum payments due in 2025	$	24,868
Less: interest expense and unamortized debt issuance costs		(372	)
2025 Notes	$	24,496

Senior Secured Term Loan

On May 8, 2024, we entered into a credit and guaranty agreement (the “Credit Agreement”) with certain holders of the 2025 Notes and certain entities managed by HealthCare Royalty Management, LLC (“HCRx”), which was subsequently assigned by HCRx to an affiliate of KKR & Co. Inc. (“KKR”) in connection with its acquisition of a majority ownership stake in HCRx in July 2025. The Credit Agreement provides for a senior secured term loan facility of $100.0 million (the “Term Loan”), which matures in May 2028 and bears interest at a variable rate equal to the applicable secured overnight financing rate plus 9.25%, subject to a floor of 3.00%. Principal payments under the Term Loan will begin in June 2026, and consist of quarterly cash payments in the amount of 6.25% of the aggregate principal amount of the Term Loan, with the remaining principal due when the Term Loan matures in May 2028.

We can prepay the Term Loan at any time. All repayments, including prepayments, are subject to a redemption fee of 3.00% of the principal paid. Prepayments made before May 8, 2027 are subject to a prepayment premium ranging from 3.00% to 5.00% of the principal prepaid. In addition, we are required to repay the Term Loan with proceeds from certain asset sales and condemnation events, subject, in some cases, to reinvestment rights.

All obligations under the Credit Agreement are secured on a first priority basis, subject to certain exceptions, by substantially all of our assets. The Credit Agreement contains customary covenants, including a requirement to maintain cash, cash equivalents and investments of at least $25.0 million at all times (the “Minimum Liquidity Covenant Amount”), and restrictions on indebtedness, liens, investments, fundamental changes, asset sales, licensing transactions, dividends, modifications to material agreements, payment of subordinated indebtedness, and other matters customarily restricted in such agreements. Specifically, we are prohibited from exclusively licensing, selling or otherwise disposing of U.S. rights to oncology indications of selinexor. As of September 30, 2025, we were in compliance with these covenants. If certain events of default occur, the Term Loan may be due and payable immediately. These events include the withdrawal of approval of certain indications of selinexor, payment defaults, covenant defaults, bankruptcy, cross-defaults to certain other agreements, change in control and lien priority.

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The outstanding balance of the Term Loan consisted of the following (in thousands):


	As of September 30, 2025			As of December 31, 2024
Principal	$	100,000		$	100,000
Less: unamortized debt issuance costs		(3,605	)		(5,397	)
Term Loan	$	96,395		$	94,603

We determined the expected life of the Term Loan was equal to its four-year term and the effective interest rate is 16.80%. The carrying value of the Term Loan approximates its fair value due to the variable interest rate. In connection with the issuance of the Term Loan, we incurred $6.8 million of debt issuance costs, which are being amortized to interest expense using the effective interest method over four years.

The following table sets forth total interest expense recognized related to the Term Loan (in thousands):


	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
	2025		2024		2025		2024
Contractual interest expense	$	3,461	$	3,686	$	10,281	$	5,872
Amortization of debt issuance costs		579		592		1,792		867
Total interest expense	$	4,040	$	4,278	$	12,073	$	6,739

Future minimum payments on the Term Loan as of September 30, 2025 were as follows (in thousands):


Years ended December 31,	Future Minimum Payments
2025	$	6,848
2026		32,223
2027		35,486
2028		60,547

Karyopharm Therapeutics Inc. 10-Q