Karyopharm Therapeutics Inc — 10-Q exhibit

Exhibit 10.10

Execution Version

THIRD AMENDMENT

TO

REVENUE INTEREST FINANCING AGREEMENT

This THIRD AMENDMENT TO REVENUE INTEREST FINANCING AGREEMENT, dated as of August 14, 2025 (this “Amendment”), is entered into by and among Karyopharm Therapeutics Inc. (the “Company”), HEALTHCARE ROYALTY PARTNERS III, L.P. (“HCRP Fund III”), HEALTHCARE ROYALTY PARTNERS IV, L.P. (“HCRP Fund IV” and together with HCRP Fund III, the “Original Investors”), HCRX INVESTMENTS HOLDCO, LLC (“Holdco,” successor-in-interest or assignee of HCRP OVERFLOW FUND, L.P. (“HCRP OF”), HCR STAFFORD FUND, L.P. (“Stafford”), HCR POTOMAC FUND, L.P. (“Potomac” and together with HCRP OF and Stafford, the “Former Investors”), HCR CANARY FUND, L.P. (“Canary”), HCR MOLAG FUND, L.P. (“Molag” which, together with Canary and each of the Former Investors, was added as an Investor to the Original Agreement (as defined below) pursuant to the First Omnibus Amendment (as defined below), with the Original Investors, Holdco, Canary, and Molag being the “Current Investors”), HEALTHCARE ROYALTY MANAGEMENT, LLC (the “Investor Representative”), and HCR KARYOPHARM SPV, LLC (the “Collateral Agent”). Each of the parties hereto is referred to individually as a “Party” and collectively as the “Parties.” KARYOPHARM THERAPEUTICS (BERMUDA) LTD. (“Karyopharm Bermuda”) has been dissolved and is not a Party to this Third Amendment. Pursuant to the Second Omnibus Amendment, HCR COLLATERAL MANAGEMENT, LLC (the “Former Collateral Agent”) has transferred all right, title, interest, and obligations under the Agreement (as defined below) and the Security Agreement (as defined in the Agreement) to the Collateral Agent and is not a Party to this Third Amendment. Pursuant to the Second Omnibus Amendment, KARYOPHARM EUROPE GMHB (“Karyopharm Europe”), has been released as a Guarantor and Grantor and is not a Party to this Third Amendment. Capitalized terms used in this Third Amendment and not defined herein shall have the meanings assigned to such terms in, or incorporated by reference into, the Agreement (as defined below), unless otherwise indicated.

RECITALS

WHEREAS, the Company and the Original Investors are parties to that certain Revenue Interest Financing Agreement, dated as of September 14, 2019, by and between the Company and the Original Investors (the “Original Agreement”), as amended by that certain Omnibus Amendment to Transaction Documents, dated as of June 23, 2021, by and among the Company, Karyopharm Europe, Karyopharm Bermuda, the Original Investors, the Former Investors, Canary, Molag, the Investor Representative, and the Collateral Agent (the “First Omnibus Amendment”), as further amended by that certain Second Amendment to Revenue Interest Financing Agreement, dated as of August 1, 2023, by and among the Company, the Former Investors, Canary, Molag, the Investor Representative, and the Collateral Agent (the “Second Amendment”), and that certain Second Omnibus Amendment to Transaction Documents, dated as of May 8, 2024, by and among the Company, Karyopharm Europe, the Original Investors, the Former Investors, Canary, Molag, the Investor Representative, the Former Collateral Agent, and the Collateral Agent (the “Second Omnibus Amendment” and the Original Agreement, as amended by the First Omnibus

Amendment, the Second Amendment, and the Second Omnibus Amendment, and as may be further amended, restated, amended and restated, supplemented, or otherwise modified from time to time, the “Agreement”);

WHEREAS, Revenue Interests (as defined in the Royalty Agreement) is due under the Royalty Agreement on August 15, 2025 (the “Quarterly Payment Date”);

WHEREAS, subject to the terms and conditions hereof, the Parties have agreed to amend the Agreement as provided in this Amendment;

NOW, THEREFORE, in consideration of the mutual covenants set forth herein and for other good and valuable consideration, the receipt and adequacy of which are hereby acknowledged, the parties hereto hereby agree as follows:

“Quarterly Payment Date” means each February 15, May 15, August 15 and November 15 following the end of the first Calendar Quarter after the Initial Closing Date (provided if any such date is not a Business Day, the Quarterly Payment Date shall be the next succeeding Business Day); provided that notwithstanding the foregoing, the Quarterly Payment Date that would have otherwise been August 15, 2025 shall be August 29, 2025 (or such later date as may be agreed to by the Parties in writing (it being agreed that email between counsels to the Company and the Investor Representative shall suffice as an agreement in writing for purposes hereof)).

[SIGNATURE PAGES FOLLOW]

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly executed, as of the date first above written.