Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. As previously disclosed, on November 2, 2026, Karyopharm Therapeutics Inc. (the “Company”) and its subsidiary, KPT Texas LLC (together with the Company, the “Debtors”) filed voluntary petitions (the “Bankruptcy Petitions”) under Chapter 11 of title 11 of the United States Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of Texas, Houston Division (su…

Regulation FD Disclosure. Commencement of the Solicitation On November 2, 2026, prior to filing the Bankruptcy Petitions, the Debtors commenced solicitation of votes on the Prepackaged Plan, including by distributing the Prepackaged Plan, Disclosure Statement and related solicitation materials to holders of claims in Classes 3-6 (as defined in the Prepackaged Plan) that were entitled to vote on the Prepackaged Plan as of the voting record date. A copy of the Disclosure Statement (including th…

Entry into a Material Definitive Agreement. The information set forth below in

Triggering Events That Accelerate or Increase a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement. The filing of the Bankruptcy Petitions described in

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The Debtors, certain of the lenders under the Credit and Guaranty Agreement (as defined below) or their affiliates or managed or controlled funds (the “DIP Lenders”) and Wilmington Savings Fund Society, FSB (“Wilmington”), as administrative agent and collateral agent (in such capacities, the “DIP Agent”), will enter into a $110 million superpriority senior secured debtor-in-posse…

Other Events. As previously disclosed on August 31, 2026, the Company submitted a supplemental New Drug Application (“sNDA”) to the U.S. Food and Drug Administration (“FDA”) seeking accelerated approval of XPOVIO ® (selinexor) in combination with ruxolitinib for the treatment of patients with myelofibrosis. The FDA’s filing review period concluded on October 27, 2026 (“Day 60”). The Company did not receive a Refuse to File notification from the FDA by Day 60, indicating that the sNDA submissi…

Bankruptcy or Receivership. On November 2, 2026 (the “Petition Date”), Karyopharm Therapeutics Inc. (the “Company”) and its subsidiary, KPT Texas LLC (the “Subsidiary” and, together with the Company, the “Debtors”) filed voluntary petitions (the “Bankruptcy Petitions”) under Chapter 11 of title 11 of the United States Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of Texas, Houston Division (such court, the “Court” and such cases, the “Cases”). Th…

| Regulation FD Disclosure. On November 2, 2026, Karyopharm Therapeutics Inc. (“Karyopharm”) issued a press release announcing that it entered into a Restructuring Support Agreement with its existing lenders and noteholders and other key stakeholders, which provides for a merger between Ayrmid Ltd. (“Ayrmid”) and a reorganized Karyopharm (the “Transaction”). To implement the Transaction, Karyopharm has filed voluntary petitions under Chapter 11 of the U.S. Bankruptcy Code in the United States…

Material Modification to Rights of Security Holders. The information contained below in

Triggering Events That Accelerate or Increase a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement. The information set forth in

will be issued in a private placement in reliance on the exemption from registration provided by Section 4(a)(2) of the Securities Act. The Company is relying on this exemption from registration based in part on representations made by each of the counterparties to the Company. The securities described herein have not been registered under the Securities Act or any state securities laws, and such securities may not be offered or sold in the United States absent registration with the SEC or an…

Entry into a Material Definitive Agreement. Forbearance Agreement On September 10, 2026, Karyopharm Therapeutics Inc. (the “Company”) and its subsidiary guarantors entered into a Forbearance Agreement and Limited Waiver to Indentures (the “Forbearance Agreement”) to provide the Company with additional time to continue to advance its myelofibrosis program, further negotiate with its lenders, pursue strategic alternatives, or consummate an equity capital raise. The Forbearance Agreement is with…

Other Events. Based on its current operating plan and assuming that the Forbearance Agreement remains in effect through October 15, 2026, the Company expects that its existing liquidity, including cash, cash equivalents, and investments as well as cash flow from net product revenue and license and other revenue, will enable the Company to fund its current operating plans until October 15, 2026. Absent additional funding or entry into one or more strategic transactions to extend the Company’s…

Other Events. On August 31, 2026, Karyopharm Therapeutics Inc. (the “Company”) announced that it has submitted a supplemental New Drug Application (“sNDA”) to the U.S. Food and Drug Administration (“FDA”) seeking Accelerated Approval for XPOVIO ® (selinexor) in combination with ruxolitinib for patients with myelofibrosis. The Company requested Priority Review of the application, which, if granted, could result in a six-month review process. The Company expects to receive notice of the FDA’s d…

Results of Operations and Financial Condition. On August 13, 2026, Karyopharm Therapeutics Inc. announced its financial results for the quarter ended June 30, 2026 and that it will conduct a previously announced, publicly available conference call to discuss those results and other company updates. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference. The informatio…

Other Events. XPORT-EC-042 Trial Topline Data On July 30, 2026, Karyopharm Therapeutics Inc. (the “Company”) announced topline results from its Phase 3 XPORT-EC-042 trial evaluating selinexor as a maintenance-only therapy compared to placebo in adult patients with TP53 wild-type advanced or recurrent endometrial cancer. The trial did not meet its primary endpoint of progression free survival (“PFS”). In the trial, patients were randomized 1:1 to receive either a 60 mg, once-weekly, administra…

The filing describes amendments to the equity incentive plan and compensatory arrangements, not a management change.

Results of Operations and Financial Condition. On May 14, 2026, Karyopharm Therapeutics Inc. announced its financial results for the quarter ended March 31, 2026 and that it will conduct a previously announced, publicly available conference call to discuss those results and other company updates. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference. The information…

Other Events. On March 24, 2026, Karyopharm Therapeutics Inc. (the “Company”) entered into a Securities Purchase Agreement with RA Capital Management (the “Investor”), pursuant to which the Company agreed to issue and sell (i) 1,030,354 shares of its common stock, par value $0.0001 per share (“Common Stock”), at a purchase price of $6.785 per share and, in lieu of Common Stock, pre-funded warrants to purchase up to 3,391,164 shares of Common Stock at a purchase price of $6.7849 per pre-funded…

Entry into a Material Definitive Agreement. Securities Purchase Agreement On March 24, 2026, Karyopharm Therapeutics Inc. (the “Company”) entered into a Securities Purchase Agreement (the “Purchase Agreement”) with RA Capital Management (the “Investor”), pursuant to which the Company agreed to issue and sell (i) 1,030,354 shares (the “Shares”) of its common stock, par value $0.0001 per share (“Common Stock”), at a purchase price of $6.785 per share and, in lieu of Common Stock, pre-funded war…

Other Events. SENTRY Trial Topline Data On March 24, 2026, the Company announced topline results from its SENTRY trial in which patients were randomized 2:1 to 60 mg of selinexor once weekly plus ruxolitinib or placebo plus ruxolitinib. The ruxolitinib dose was determined based on the patients’ baseline platelet count per the drug’s prescribing information. All data presented are as of the data cut-off date of February 20, 2026. The SENTRY trial met the first co-primary endpoint, demonstratin…

Unregistered Sales of Equity Securities. The information set forth under

Regulation FD Disclosure. SENTRY Trial Topline Data On March 24, 2026, the Company issued a press release announcing topline results from its pivotal Phase 3 SENTRY trial, a randomized, double-blind, placebo-controlled trial of 60 mg selinexor in combination with ruxolitinib in frontline myelofibrosis (n=353) (the “SENTRY trial”). A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The Company intends to host a conference call and live webcast to discu…

Other Items. Forbearance Agreement On February 27, 2026, the Company entered into a Forbearance Agreement (the “Forbearance Agreement”) with (i) 100% of the lenders under the Credit Agreement, (ii) holders representing 100% of the outstanding principal amount of the Company’s 9.00% Convertible Senior Notes due 2028 (the “2028 Notes”), (iii) holders representing 100% of the outstanding principal amount of the Company’s 9.00% Convertible Senior Notes due 2029 (the “2029 Notes”), and (iv) the in…

Entry into a Material Definitive Agreement. On February 27, 2026, Karyopharm Therapeutics Inc. (the “Company”) entered into the Second Amendment to Credit and Guaranty Agreement (the “Amendment”) with the lenders party thereto and Wilmington Savings Fund Society, FSB, as administrative agent and collateral agent, which amends the Company’s Credit and Guaranty Agreement, dated May 8, 2024 (as previously amended, the “Credit Agreement”). The purpose of the Amendment and the Forbearance Agreemen…