Exchange for Karyopharm Therapeutics Inc. 9.00% Convertible Senior Notes due 2029 and New Warrants to Purchase Common Stock

The Exchange. Subject to the terms and conditions of this Exchange Agreement, the Investor and the other Exchanging Holders hereby deliver, assign and transfer to the Company all right, title and interest in the aggregate principal amount of Old Notes set forth in column 2 of Exhibit A (such principal amount of Old Notes, the “Exchanged Old Notes”) and surrender the Old Warrants exercisable for the number of shares of Stock set forth in column 4 of Exhibit A (the “Exchanged Old Warrants,” and together with the Exchanged Old Notes, the “Old Securities”) in exchange for: (i) New Notes having an aggregate principal amount, for each Exchanging Holder, as set forth in column 3 of Exhibit A (such aggregate principal amount of New Notes, the “Exchanged New Notes”) and (ii) the New Warrants exercisable for a number of shares of Stock, for each Exchanging Holder, as set forth in column 5 of Exhibit A, (the “Exchanged New Warrants,” and together with the Exchanged New Notes, the “New Securities”), and the Company agrees to deliver the applicable amounts of such Exchanging Holder’s New Securities to such Exchanging Holder in exchange for such Old Securities tendered by such Exchanging Holder in the Exchange on the Closing Date. For the avoidance of doubt, Exchanged New Notes will be issued in denominations of $1 principal amount and integral multiples thereof, and the Company will not make any separate cash payment in respect of rounded amounts. Subject to the terms and conditions of this Exchange Agreement, the Investor, on behalf of itself and each Exchanging Holder, hereby (a) waives any and all rights with respect to such Exchanged Old Notes and Exchanged Old Warrants, and (b) releases and discharges the Company from any and all claims the Investor and each Exchanging Holder may now have, or may have in the future, arising out of, or related to, such Exchanged Old Notes or Exchanged Old Warrants. For the avoidance of doubt, there shall be no payments of accrued and unpaid interest on the Old Notes from, and including, April 15, 2024 to, but excluding, the Closing Date in connection with the Exchange.

The Closing. The closing of the Exchange (the “Closing”) shall take place electronically at 8:00 AM, New York City time, on October 10, 2025, or at such other time and place as the Company may designate by notice to the Investor (the “Closing Date”); provided that the Closing Date cannot be later than October 15, 2025 (the “Cutoff Date”) without the prior written consent of the Company and the Investor.

Closing Mechanics.

The Depository Trust Company (“DTC”) will act as securities depositary for the New Notes.

At or prior to the times set forth in the Exchange Procedures set forth in Exhibit F hereto (the “Exchange Procedures”), the Investor, on behalf of itself and/or any other Account, shall deliver and/or cause the Exchanging Holders to deliver the Exchanged Old Notes, by book entry transfer through the facilities of DTC, to the Old Notes Trustee, for the account/benefit of the Company for cancellation as instructed in the Exchange Procedures;

On or prior to the Closing Date, subject to satisfaction of the conditions precedent specified in Section 6 hereof, and the prior receipt by the Old Notes Trustee from each Exchanging Holder of the Exchanged Old Note:

each Exchanging Holder shall execute and deliver, and cause the New Notes Trustee and the Collateral Trustee to execute and deliver, this Exchange Agreement and each Transaction Document to which it and/or the Collateral Trustee is a party;

the Company and each Guarantor shall execute and deliver, and cause the New Notes Trustee and the Collateral Trustee to execute and deliver, each Transaction Document to which the Company, a Guarantor, the New Notes Trustee and/or the Collateral Trustee is a party; and

in connection with the foregoing clause (ii), the Company shall execute, cause the New Notes Trustee to authenticate and cause to be delivered to the DTC account(s) specified by the Investor or the relevant Account in Exhibit G hereto, the Exchanged New Notes.

Upon consummation of the Exchange as specified herein, subject to satisfaction of the conditions precedent specified in Section 6 hereof, (i) the Company shall execute and deliver to each Exchanging Holder the New Warrants exercisable for the applicable number of Warrant Shares due to such Exchanging Holder and (ii) the Old Warrants shall be deemed automatically surrendered, delivered and cancelled.

Representations and Warranties of the Company. The Company represents and warrants to the Investor (and each Account, as applicable), on behalf of itself and each of the Guarantors, if any, that:

Organization. The Company and each of the Guarantors is duly organized and validly existing as a corporation, limited liability company, limited partnership or

Due Authorization. This Exchange Agreement has been duly authorized, executed and delivered by the Company.

New Securities. The New Notes have been duly authorized by the Company and, when duly executed by the Company in accordance with the terms of the New Notes Indenture, assuming due authentication of the New Notes by the New Notes Trustee, upon delivery to the Exchanging Holders in accordance with the terms of the Exchange, will be validly issued and delivered, will constitute valid and binding obligations of the Company and each of the applicable Guarantors and will be entitled to the benefits of the New Notes Indenture, enforceable against the Company and each such Guarantor in accordance with their terms, except as such enforceability may be limited by bankruptcy, fraudulent conveyance, insolvency, reorganization, moratorium, and other laws relating to or affecting creditors’ rights generally and by general equitable principles (regardless of whether such enforceability is considered in a proceeding in equity or at law) and except insofar as enforceability of indemnification or contribution provisions may be limited by applicable law or public policy (collectively, the “Enforceability Exceptions”). The New Warrants have been duly authorized by the Company and, when duly executed by the Company, upon delivery to the Exchanging Holders in accordance with the terms of the Exchange, will be validly issued and delivered, will constitute valid and binding obligations of the Company, enforceable against the Company, subject to the Enforceability Exceptions. The maximum number of Underlying Shares initially issuable upon conversion of the New Notes (including the principal amount of Notes expected to be issued as PIK Interest (as defined in the Indenture) pursuant to Section 2.03(d) of the Indenture and assuming settlement in shares of Stock to the maximum extent permitted by the New Notes Indenture and taking into account the maximum make-whole adjustment under the New Notes Indenture) and the Warrant Shares initially issuable upon exercise of the New Warrants (assuming full exercise of the New Warrants) have been duly and validly authorized and reserved for by the Company and, when issued upon conversion of the New Notes in accordance with the terms of the New Notes and the New Notes Indenture or upon exercise of the New Warrants in accordance with the terms of the New Warrants, as applicable, will be validly issued, fully paid and non-assessable, and the issuance of any Underlying Shares or Warrant Shares, as applicable, will not be subject to any preemptive, participation, rights of first refusal or similar rights. On

Transaction Documents. The Company and each Guarantor, as applicable, has all requisite corporate power and authority to perform its obligations under each Transaction Document, to the extent applicable. Each Transaction Document has been duly authorized by the Company and each Guarantor, as applicable, and will have been duly executed and delivered by the Company and each Guarantor, as applicable, on or prior to the Closing. Assuming due authorization, execution and delivery by the other parties thereto, each Transaction Document, upon execution and delivery thereof by the Company and each Guarantor, as applicable, will constitute the valid and binding agreement of the Company and each Guarantor, enforceable against the Company and each Guarantor in accordance with its terms, subject to the Enforceability Exceptions.

Exemption from Registration. Assuming the accuracy of the representations and warranties of the Investor and each other investor executing an Exchange Agreement, (1) the issuance of the New Securities in connection with the Exchange pursuant to this Exchange Agreement is exempt from the registration requirements of the Securities Act pursuant to 4(a)(2) of the Securities Act; (2) when issued to an Exchanging Holder, the New Notes will be issued free of any restrictive legend and issued with an “unrestricted” CUSIP; and (3) the New Notes Indenture is not required to be qualified under the Trust Indenture Act of 1939, as amended.

New Class. The New Notes, when issued, will not be of the same class as securities listed on a national securities exchange registered under Section 6 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or quoted in a U.S. automated inter-dealer quotation system, within the meaning of Rule 144A(d)(3)(i) under the Securities Act.

No Conflicts. The execution, delivery and performance of the Transaction Documents by the Company and the Guarantors, as applicable, and the consummation of the transactions contemplated hereby and thereby, including the issuance of the New Notes and the New Warrants and any issuance of Underlying Shares and Warrant Shares, and the granting of any liens or other security interests to be granted by the Company or the Guarantors pursuant to the New Notes Indenture and Security Agreement, as applicable, will not: (i) result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement, license, lease or other agreement or instrument to which the Company or any Guarantor is a party or by which the Company or any Guarantor is bound or to which any of the property or assets of the Company or any Guarantor is subject, (ii) result in any violation of the provisions of the charter or by-laws or similar organizational document of the Company or any Guarantor or (iii) result in any violation of any statute or any judgment, order, decree, rule or regulation of any court or arbitrator or federal, state,

Governmental Authorizations. Except in each case, as would not reasonably be expected, individually or in the aggregate, to have a material adverse effect on the Company and the Guarantors taken as a whole: (a) the Company and the Guarantors possess all certificates, authorizations and permits issued by the appropriate federal, state or foreign regulatory authorities necessary to conduct their respective businesses (the “Required Authorizations”), none of the Company nor any of the Guarantors has received any notice of proceedings relating to the revocation or modification of any such Required Authorizations and all Required Authorizations are valid and in full force and effect, and (b) no authorization of, or registration, notice or filing with, any governmental authority is required for (i) the execution, delivery and performance of any of the Transaction Documents, and (ii) the consummation by the Company or any of the Guarantors of the transactions contemplated by the Transaction Documents, except (A) for such as have already been obtained or made prior to the Closing Date that are in full force and effect, (B) for those required in connection with the perfection of any security interest in or exercise of remedies in respect of any collateral securing the New Notes, (C) pursuant to applicable federal and state securities laws, rules and regulations that are expressly contemplated by Section 13 or 15(d) of the Exchange Act and by the Registration Rights Agreement, or (D) for filings expressly contemplated or required by the Transaction Documents.

Collateral Documents. Upon execution and delivery, the Security Agreement will be effective to grant a legal, valid and enforceable security interest in all of the grantor’s right, title and interest in the collateral described therein. The Company and the Guarantors collectively own, have rights in or have the power and authority to grant the liens contemplated by the Security Agreement in the Collateral (as defined in the New Notes Indenture) securing the New Notes, free and clear of any liens other than the Permitted Liens.

SEC Reporting. The Company has timely filed all reports, schedules, forms, proxy statements, statements and other documents required to be filed by it with the Securities and Exchange Commission (the “SEC”) pursuant to the reporting requirements of the Exchange Act (all of the foregoing filed prior to the date hereof and all exhibits and appendices included therein and financial statements, notes and schedules thereto and documents incorporated by reference therein being hereinafter referred to as the “SEC Reports”) from January 1, 2025 to the date of

Nasdaq Compliance. The Company is in compliance in all material respects with the applicable listing and corporate governance rules and regulations of Nasdaq. No approval of the stockholders of the Company under the rules and regulations of Nasdaq (including Rule 5635 of the Nasdaq Listing Rules) is required to issue and deliver the New Notes to the Investor.

Legal Proceedings. There is no action, lawsuit, arbitration, claim or proceeding pending or, to the knowledge of the Company, threatened, against the Company that would reasonably be expected to impede the consummation of the Exchange.

Capitalization. The Company is authorized under its amended and restated certificate of incorporation (the “Certificate of Incorporation”) to issue 53,333,333 shares of Stock. The Company’s disclosure of its issued and outstanding capital stock in its most recent SEC Report containing such disclosure was accurate in all material respects as of the date indicated in such SEC Report. All of the issued and outstanding shares of the Company’s capital stock have been duly authorized and validly issued and are fully paid and nonassessable; none of such shares were issued in violation of any preemptive rights; and such shares were issued in compliance with applicable state and federal securities law and any rights of third parties. No person is entitled to preemptive or similar statutory or contractual rights with respect to the issuance by the Company of any securities of the Company. Except for the Recapitalization Transactions (including, for the avoidance of doubt, the Exchange contemplated hereunder) and the consummation of any other transactions occurring simultaneously on or about the Closing Date in relation to the Recapitalization, the 5,000 shares of Stock to be delivered to Neumedicines Inc. contingent upon certain terms of that certain Asset Purchase Agreement with Neumedicines Inc. dated as of November 24, 2020, shares of Stock issued or issuable under the Company’s employee stock purchase plan and options, restricted stock or restricted stock units granted or that may be granted under Company stock-based compensation plans that are described in the SEC Reports, there are no outstanding warrants, options, convertible securities or other rights, agreements or arrangements of any character under which the Company is or may be obligated to issue any equity securities of any kind, except as contemplated by this Exchange Agreement or as previously disclosed in the Company’s SEC Reports. There are no voting agreements, buy-sell agreements, option or right of first purchase agreements or other similar agreements among the Company and any of the securityholders of the Company relating to the securities of the Company held by them. No person has the right to require the Company to register any securities of the Company under the Securities Act, whether on a demand basis or in connection with the registration of securities of the Company for its own account or for the account of any other person, other than pursuant to that certain registration rights agreement dated December 5, 2022, those certain registration rights agreements dated May 13, 2024 and any registration rights agreements entered into in

Exchange. The Company acknowledges that the terms of the Exchange have been mutually negotiated between the parties.

Solvency. Upon the consummation of the Recapitalization Transactions, the Company will be Solvent. “Solvent” means with respect to any Person, that as of the date of determination, (a) the sum of such Person’s debt (including contingent liabilities) does not exceed the present fair saleable value of such Person’s present assets; (b) such Person’s capital is not unreasonably small in relation to its business as contemplated on such date of determination; and (c) such Person has not incurred and does not intend to incur, or believe (not should it reasonably believe) that it will incur, debts beyond its ability to pay such debts as they become absolute and matured. For purposes of this definition, the amount of any contingent liability at any time shall be computed as the amount that, in light of all of the facts and circumstances existing at such time, represents the amount that can reasonably be expected to become an actual or matured liability (irrespective of whether such contingent liabilities meet the criteria for accrual under FASB Accounting Standards Codification Topic 450-20).

Investment Company. The Company is not and, after giving effect to the transactions contemplated by this Exchange Agreement, will not be required to register as an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the SEC thereunder.

FIRPTA. The Company has never been, and expects not to be in the current taxable year or in the foreseeable future, a “United States real property holding corporation” within the meaning of Section 897 of the Internal Revenue Code of 1986, as amended.

Earnings and Profits. The Company does not expect to have any current or accumulated earnings and profits from operations for its current taxable year.

Other Representations and Warranties. The representations and warranties of the Company made in Section 4 of the Amended Credit Agreement, shall be true and correct in all material respects (except for those which have a materiality qualifier, which shall be true and correct in all respects as so qualified) as of the Closing Date, except to the extent any such representations and warranties are expressly limited to an earlier date, in which case, as of the Closing Date, such representations and warranties shall continue to be true and correct in all material respects (except for those which have a materiality qualifier, which shall be true and correct in all respects as so qualified) as of such specified earlier date.

Representations and Warranties of the Investor. The Investor hereby represents and warrants to and covenants with the Company, on behalf of itself and each Account, as applicable, that:

The Investor is validly existing as a corporation, limited liability company, limited partnership or other form, as applicable, and is in good standing (to the extent such concept is applicable in the relevant jurisdictions) under the laws of the jurisdiction of its incorporation, organization or formation, as applicable.

The Investor has all requisite corporate, limited partnership, limited liability company or other applicable entity power and authority to deliver, assign and transfer the Exchanged Old Notes in exchange for the New Securities pursuant to this Exchange Agreement and to enter into this Exchange Agreement and perform all obligations required to be performed by the Investor hereunder. This Exchange Agreement, when executed and delivered, has been duly authorized, executed and delivered by the Investor and constitutes the valid and binding obligation of the Investor and each Exchanging Holder, enforceable in accordance with its terms, except that such enforcement may be subject to the Enforceability Exceptions. If the Investor is executing this Exchange Agreement on behalf of an Account, (i) the Investor has all requisite discretionary and contractual authority to enter into this Exchange Agreement on behalf of, and, bind, each Account to the terms of this Exchange Agreement and (ii) Exhibit A is a true, correct and complete list of (A) the name of each Exchanging Holder, and (B) the principal amount of each Exchanging Holder’s Exchanged Old Notes.

Each Exchanging Holder participating in the Exchange is the current beneficial owner of the Exchanged Old Notes. When the Exchanged Old Notes are exchanged, the Company will acquire good, marketable and unencumbered title thereto, free and clear of all liens, restrictions, charges, encumbrances, adverse claims, rights or proxies. Each Exchanging Holder participating in the Exchange is the current beneficial owner of the Old Warrants. When the Old Warrants are deemed surrendered pursuant to the terms of this Exchange Agreement, each Exchanging Holder acknowledges and agrees that the Old Warrants shall cease to be in full force and effect.

Participation in the Exchange will not contravene (1) any law, rule, regulation or governmental or judicial decrees, injunctions or orders binding on the Investor or any Account or any investment guideline or restriction applicable to the Investor (or, if applicable, any Account), (2) the charter or bylaws (or equivalent organizational documents) of the Investor (or, if applicable, any Account) or (3) any agreement or instrument to which the Investor or any Account is a party or by which the Investor or any Account or any of their respective assets are bound.

The Investor (or applicable Account) is a resident of the jurisdiction set forth in Exhibit G and, unless otherwise set out in Exhibit A, is not acquiring the Exchanged New Notes as a nominee or agent or otherwise for any other person.

The Investor and each Account will comply with all applicable laws and regulations in effect in any jurisdiction in which the Investor or such Account acquires, pursuant to the Exchange, or sells New Notes and will obtain any consent, approval or permission required for such acquisitions or sales under the laws and regulations of any jurisdiction to which the Investor or such Account is subject or in which the Investor or such Account makes such acquisitions or sales, and the Company shall not have any responsibility therefor.

The Investor and each Account have received a copy of the Transaction Documents. The Investor acknowledges that: (1) no person has been authorized to give any information or to make any representation concerning the Exchange or the Company or any Guarantor, other than as contained in this Exchange Agreement or the Transaction Documents; and (2) the Company and the Guarantors do not take any responsibility for, and cannot provide any assurance as to the reliability of, any other information that may have been provided to the Investor. The Investor hereby acknowledges that Centerview Partners LLP and J. Wood Capital Advisors LLC (the “Exchange Advisors”) do not take any responsibility for, and can provide no assurance as to the reliability of, the information set forth in the Transaction Documents or any such other information provided or deemed provided to the Investor by the Company.

The Investor and each Account understands and accepts that acquiring the Securities involves risks. The Investor and each Account has such knowledge, skill and experience in business, financial and investment matters that the Investor and each Account is capable of evaluating the merits and risks of the Exchange and an investment in the Securities. With the assistance of its own professional advisors (to the extent the Investor and each Account has deemed appropriate), the Investor and each Account has made its own legal, tax, accounting and financial evaluation of the merits and risks of an investment in the Securities and the consequences of the Exchange and this Exchange Agreement. The Investor and each Account has considered the suitability of the Securities as an investment in light of its own circumstances and financial condition, and the Investor is, and each Account is, able to bear the risks associated with an investment in the Securities. The Investor and each Account understands that it should consult with its own tax advisors in order to determine the U.S. federal, state and local tax consequences of the Exchange as well as the ownership and disposition of the Securities.

The Investor confirms that neither it nor any Account is relying on any communication (written or oral) of the Company or the Exchange Advisors or any of their respective agents or affiliates as investment advice or as a recommendation to participate in the Exchange and receive the New Securities pursuant to the terms hereof. The Investor confirms that it has read the New Notes Indenture relating to the New Notes and the New Warrants and has not relied on any statement (written or oral) of the Company, the Exchange Advisors or any of their respective affiliates as to the terms of the New Notes or New Warrants. It is understood that information provided in the Transaction Documents, or by the Company or the Exchange Advisors or any of their respective agents or affiliates, shall not be considered

The Investor confirms, for itself and for each Account, that neither the Company nor the Exchange Advisors have (1) given any guarantee or representation as to the potential success, return, effect or benefit (either legal, regulatory, tax, financial, accounting or otherwise) of an investment in the Securities; or (2) made any representation to the Investor regarding the legality of an investment in the Securities under applicable investment guidelines, laws or regulations. In deciding to participate in the Exchange, neither the Investor nor any Account is relying on the advice or recommendations of the Company or the Exchange Advisors, and the Investor and each Account has made its own independent decision that the investment in the Securities is suitable and appropriate for the Investor or such Account.

The Investor and each Account is a sophisticated participant in the transactions contemplated hereby and has such knowledge and experience in financial and business matters as to be capable of evaluating the merits and risks of an investment in the Securities, is experienced in investing in capital markets and is able to bear the economic risk of an investment in the Securities. The Investor and each Account is familiar with the business and financial condition and operations of the Company and the Guarantors and has conducted its own investigation of the Company and the Guarantors and the Securities and has consulted with its own advisors concerning such matters and shall be responsible for making its own independent investigation and appraisal of the transactions contemplated hereby. The Investor and each Account has had access to the Company filings with the SEC and such other information concerning the Company and the Guarantors and the Securities as it deems necessary to enable it to make an informed investment decision concerning the Exchange. The Investor and each Account has been offered the opportunity to ask questions of the Company and its representatives and has received answers thereto as the Investor or such Account deems necessary to enable it to make an informed investment decision concerning the Exchange and the Securities. Neither such inquiries nor any other due diligence investigations conducted by such Investor or its advisors, or its representatives shall modify, amend or affect such Investor’s right to rely on the Company’s representations and warranties contained herein.

The Investor and each Account understands that no federal, state, local or foreign agency has passed upon the merits or risks of an investment in the Securities or made any finding or determination concerning the fairness or advisability of such investment.

The Investor and each Account is an institutional “accredited investor” as defined in Rule 501 of Regulation D under the Securities Act as well as a “qualified institutional buyer” as defined in Rule 144A under the Securities Act. The Investor,

The Investor and each Account is not directly, or indirectly through one or more intermediaries, controlling or controlled by, or under direct or indirect common control with, the Company and is not, and has not been for the immediately preceding three months, an “affiliate” (within the meaning of Rule 144 under the Securities Act) of the Company.

The Investor and each Account hereby confirms that its Exchanged Old Notes were either (i) acquired more than one year prior to the Closing Date or (ii) acquired from a noteholder who such Exchanging Holder had no reason to believe was, at the time of such sale or the immediately preceding three months, an “affiliate” (within the meaning of Rule 144 under the Securities Act) of the Company, and further hereby confirms that such Investor and each Account hereby confirms that it is entitled to rely on Rule 144(d) (3)(ii) in connection with its acquisition of the Securities (other than any Warrant Shares issued upon cash exercise of the New Warrants).

The Investor and each Account is acquiring the Securities solely for the Investor’s or such Account’s own beneficial account, or for an account with respect to which the Investor or such Account exercises sole investment discretion, for investment purposes, and not with a view to, or for resale in connection with, any distribution of the Securities in violation of federal, state or other applicable securities laws. The Investor and each Account understands that the offer and sale of the Securities have not been registered under the Securities Act or any state securities laws by reason of specific exemptions under the provisions thereof that depend in part upon the representations made by the Investor and each Account in this Exchange Agreement.

The Investor and each Account understands that the Company is relying upon the representations and agreements contained in this Exchange Agreement (and any supplemental information) for the purpose of determining whether the Investor’s and such Account’s participation in the Exchange meets the requirements for the exemptions referenced in clause (o) above and whether the New Notes and the New Warrants may be issued without legends.

The Investor and each Account acknowledges and agrees that since the time such Investor or Account was wall crossed it has not, and prior to the Closing it will not, engage in any hedging transactions with respect to the Securities and that any hedging transactions that thereafter may be engaged in by it with respect to the Securities it will be conducted in compliance with the Securities Act and the rules and regulations promulgated thereunder and all other applicable laws.

The Investor and each Account acknowledges that the terms of the Exchange have been mutually negotiated between the Investor (for itself and on behalf of each Account), and the Company. The Investor was given a meaningful opportunity to negotiate the terms of the Exchange on behalf of itself and each Account.

The Investor and each Account acknowledges the Company intends to pay an advisory fee to the Exchange Advisors.

The Investor will, for itself and on behalf of each Account, upon request, execute and deliver any additional documents, information or certifications reasonably requested by the Company, the Old Notes Trustee or the New Notes Trustee to complete the Exchange.

The Investor and each Account understands that, unless the Investor notifies the Company in writing to the contrary prior to the Closing, each of the Investor’s representations and warranties contained in this Exchange Agreement will be deemed to have been reaffirmed and confirmed as of the Closing, taking into account all information received by the Investor.

The participation in the Exchange by any Exchanging Holder was not conditioned by the Company on such Exchanging Holders’ exchange of a minimum principal amount of Exchanged Old Notes or its participation, if any, in the Term Loan Agreement (as defined in the New Notes Indenture).

The Investor acknowledges that it and each Account had a sufficient amount of time to consider whether to participate in the Exchange and that neither the Company nor the Exchange Advisors have placed any pressure on the Investor or any Account to respond to the opportunity to participate in the Exchange. The Investor acknowledges that neither it nor any Account became aware of the Exchange through any form of general solicitation or advertising within the meaning of Rule 502 under the Securities Act.

The operations of the Investor and each Account have been conducted in material compliance with the rules and regulations administered or conducted by the U.S. Department of Treasury Office of Foreign Assets Control (“OFAC”), the rules and regulations of the Foreign Corrupt Practices Act (“FCPA”) and the Anti-Money Laundering (“AML”) rules in the Bank Secrecy Act applicable to the Investor. The Investor has performed due diligence necessary to reasonably determine that its (or, where applicable, any Account’s) beneficial owners are not named on the lists of denied parties or blocked persons administered by OFAC, resident in or organized under the laws of a country that is the subject of comprehensive economic sanctions and embargoes administered or conducted by OFAC (“Sanctions”), are not otherwise the subject of Sanctions and have not been found to be in violation or under suspicion of violating OFAC, FCPA or AML rules and regulations.

The Investor and each Account acknowledges and agrees that the Exchange Advisors have not acted as a financial advisor or fiduciary to the Investor or such Account and that the Exchange Advisors and their respective directors, officers, employees, representatives and controlling persons have no responsibility for

The Investor and each Account acknowledges and agrees that no public market exists for the New Notes or New Warrants and that there is no assurance that a public market will ever develop for the New Notes or New Warrants.

The Investor and each Exchanging Holder acknowledges and understands that as of the date of this Exchange Agreement and at the time of the Closing, the Company may be in possession of material non-public information not known to the Investor or any Exchanging Holder that may impact the value of the Old Notes and the Securities (“Information”) that the Company has not disclosed to the Investor or any Exchanging Holder. The Investor and each Exchanging Holder acknowledges that they have not relied upon the non-disclosure of any such Information for purposes of making their decision to participate in the Exchange. The Investor and each Exchanging Holder understands, based on its experience, the disadvantage to which the Investor and each Exchanging Holder is subject due to the disparity of information between the Company, on the one hand, and the Investor and each Exchanging Holder, on the other hand. Notwithstanding this, the Investor and each Exchanging Holder has deemed it appropriate to participate in the Exchange. The Investor agrees that the Company and its directors, officers, employees, agents, stockholders and affiliates shall have no liability to the Investor or any Exchanging Holder or their respective beneficiaries whatsoever due to or in connection with the Company’s use or non-disclosure of the Information or otherwise as a result of the Exchange, and the Investor hereby irrevocably waives any claim that it or any Exchanging Holder might have based on the failure of the Company to disclose the Information.

Conditions to Obligations of the Investor and the Company. The obligations of the Investor to deliver, or to cause the Accounts to deliver, the Old Securities and of the Company to deliver the New Securities are subject to the satisfaction at or prior to the Closing of the condition precedent that the representations and warranties of the Company on the one hand, and of the Investor on the other contained in Sections 4 and 5, respectively, shall be true and correct as of the Closing in all material respects with the same effect as though such representations and warranties had been made as of the Closing. The obligations of the Investor hereunder are also subject to the satisfaction at or prior to Closing of the conditions precedent that (i) the Company has satisfied its obligations under Section 7(e) with respect to any invoices received on or before Closing by Closing, (ii) the Investor shall have received a legal opinion of Sidley Austin LLP in form and substance reasonably satisfactory to the Investor pursuant to Section 7(d), (iii) the Company shall not have breached any of the covenants contained in Section 7, (iv) the Company shall not have

Covenants and Acknowledgments of the Company.

The Company hereby agrees to publicly disclose at or prior to 9:00 a.m., New York City time (the “Release Time”), on the first business day after the date hereof, the Exchange as contemplated by this Exchange Agreement in a press release or through the filing of a Current Report on Form 8-K. The Company hereby acknowledges and agrees that as of the Release Time the Company will disclose all confidential information to the extent the Company believes such confidential information constitutes material non-public information that was communicated by the Company to the Investor or any Account in connection with the Exchange, if any. For the avoidance of doubt, the Company may be aware of other material non-public information regarding the Company at the time of Closing that has not been communicated to the Investor or any Account. The Company will, no later than the first business day following the Closing, file a Current Report on Form 8-K publicly disclosing the Closing as contemplated by this Exchange Agreement. Prior to the filing of any Current Report on Form 8-K or publication of any press release, which in either case would include the name of the Investor or any of its affiliates, the Company hereby agrees to provide such press release or Current Report on Form 8-K to the Investor at least one (1) day prior to publication or filing, as applicable, of such press release or Current Report on Form 8-K.

From and after the date hereof, the Company shall at all times reserve and keep available (free of preemptive or similar rights) from its authorized but unissued shares of Stock, solely for the purpose of effecting conversions of the New Notes and the exercise of the New Warrants, such number of shares of Stock as shall from time to time be sufficient to effect the conversion in full of the New Notes and the exercise in full of the New Warrants (without giving effect to any beneficial ownership caps contained in the New Notes and New Warrants or any other restriction or limitation on exercise contained in the New Notes and New Warrants) to the extent required by the Indenture; and if at any time the number of authorized but unissued shares of Stock shall not be sufficient to effect the conversion in full of the New Notes or the exercise in full of the New Warrants (without giving effect to any beneficial ownership caps contained in the New Notes and New Warrants or any other restriction or limitation on exercise contained in the New Notes or New Warrants), the Company will use reasonable best efforts to take such corporate action as may be necessary to increase its authorized but unissued shares of Stock to at least such number of shares as shall be sufficient for such purpose.

The Company agrees that it shall, upon request, execute and deliver any additional documents deemed by the Old Notes Trustee, transfer agent or Investor to be reasonably necessary to complete the Exchange.

On the Closing Date the Company shall deliver to the Investor a legal opinion of Sidley Austin LLP in form and substance reasonably satisfactory to the Investor.

The Company covenants and agrees to promptly pay or reimburse the Investor upon request for all reasonable and documented out-of-pocket expenses, disbursements and advances incurred or made by the Investor through the Closing in connection with the execution of this Exchange Agreement (including the reasonable and documented fees and the expenses and disbursements of no more than two counsels, which shall be Latham & Watkins LLP and Gibson, Dunn and Crutcher LLP (“GDC”), provided that the fees of GDC, when taken together with their fees and the expenses and disbursements in connection with the execution of the Private Placement, shall be limited to reasonable and documented fees and expenses and disbursements not exceeding $50,000). The provisions of this Section 7(e) shall survive the termination of this Exchange Agreement.

Covenant of the Investor. No later than one (1) business day after the date hereof, the Investor agrees to deliver settlement instructions for each Exchanging Holder to the Company substantially in the form of Exhibit G.

Waiver, Amendment. Neither this Exchange Agreement nor any provisions hereof shall be modified, changed, discharged or terminated except by an instrument in writing, signed by the party against whom any waiver, change, discharge or termination is sought.

Assignability. Neither this Exchange Agreement nor any right, remedy, obligation or liability arising hereunder or by reason hereof shall be assignable by the Company or the Investor without the prior written consent of the other party.

Withholding; Required Tax Forms. The Investor (or Account(s) of such Investor, if applicable) shall deliver to the Company, at least one (1) business day prior to the Closing, an accurately completed and duly executed IRS Form W-9 or IRS Form W-8BEN, W-8BEN-E or W-8ECI, as applicable (or any successor form). The Investor (or Account(s) of such Investor, if applicable) acknowledges that, if the Investor (or Account(s) of such Investor, if applicable) (i) is a “United States person” (as defined in Section 7701(a) of the Internal Revenue Code of 1986, as amended (the “Code”)), then the Company must be provided with a correct taxpayer identification number (generally, a person’s social security number or federal employer identification number) or (ii) is not a “United States person” (as defined in Section 7701(a) of the Code) (a “Non-U.S. Holder”), then the Company must be provided with an accurately completed and duly executed IRS Form W-8BEN, W-8BEN-E or W-8ECI, as applicable (or any successor form), establishing an exemption from or a reduction in U.S. federal withholding on interest or original issue discount. The Investor (or Account(s) of such Investor, if applicable) further acknowledges that any Investor (or Account(s) of such Investor, if applicable) may be subject to 30% U.S. federal withholding on certain payments or deliveries made to such Investor (or Account(s) of such Investor, if applicable) attributable to accrued and unpaid interest or original issue discount or 24% U.S. federal backup withholding on certain payments or deliveries made to such Investor (or Account(s) of such Investor, if applicable) unless such Investor (or Account(s) of such Investor, if applicable) properly establishes an exemption from, or a

Waiver of Jury Trial. EACH OF THE COMPANY AND THE INVESTOR (FOR ITSELF AND, IF APPLICABLE, ON BEHALF OF EACH ACCOUNT) IRREVOCABLY WAIVES ANY AND ALL RIGHT TO TRIAL BY JURY WITH RESPECT TO ANY LEGAL PROCEEDING ARISING OUT OF THE TRANSACTIONS CONTEMPLATED BY THIS EXCHANGE AGREEMENT.

Governing Law. THIS EXCHANGE AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO CONFLICT OF LAW PRINCIPLES THAT WOULD RESULT IN THE APPLICATION OF ANY LAW OTHER THAN THE LAW OF THE STATE OF NEW YORK.

Submission to Jurisdiction. Each of the Company and the Investor (for itself and, if applicable, on behalf of each Account) (a) agrees that any legal suit, action or proceeding arising out of or relating to this Exchange Agreement or the transactions contemplated hereby shall be instituted exclusively in the courts of the State of New York located in the City and County of New York or in the United States District Court for the Southern District of New York; (b) waives any objection that it may now or hereafter have to the venue of any such suit, action or proceeding; and (c) irrevocably consents to the jurisdiction of the aforesaid courts in any such suit, action or proceeding. Each of the Company and the Investor (for itself and, if applicable, on behalf of each Account) agrees that a final judgment in any such action or proceeding shall be conclusive and may be enforced in other jurisdictions by suit on the judgment or in any other manner provided by law.

Venue. Each of the Company and the Investor (for itself and, if applicable, on behalf of each Account) irrevocably and unconditionally waives, to the fullest extent it may legally and effectively do so, any objection which it may now or hereafter have to the laying of venue of any suit, action or proceeding arising out of or relating to this Exchange Agreement in any court referred to in Section 14. Each of the Company and the Investor (for itself and, if applicable, on behalf of each Account) irrevocably waives, to the fullest extent permitted by law, the defense of an inconvenient forum to the maintenance of such action or proceeding in any such court.

Service of Process. Each of the Company and the Investor (for itself and, if applicable, on behalf of each Account) irrevocably consents to service of process in the manner provided for notices in Section 19. Nothing in this Exchange Agreement will affect the right of any party to this Exchange Agreement to serve process in any other manner permitted by law.

Section and Other Headings. The section and other headings contained in this Exchange Agreement are for reference purposes only and shall not affect the meaning or interpretation of this Exchange Agreement.

Counterparts. This Exchange Agreement may be executed, either manually or by way of a digital signature provided by DocuSign (or similar digital signature provider), by one or more of the parties hereto in any number of separate counterparts (including by facsimile or other electronic means, including telecopy, email or otherwise and including any electronic signature covered by the U.S. federal E-SIGN Act of 2000, Uniform Electronic Transactions Act, the Electronic Signatures and Records Act or other applicable law), and all of said counterparts taken together shall be deemed to constitute one and the same instrument. Delivery of an executed signature page of this Exchange Agreement (whether executed manually or by way of a digital signature as described herein this Section 18) by facsimile or other transmission (e.g., “pdf” or “tif” format) shall be effective as delivery of a manually executed counterpart hereof.

Notices. All notices and other communications to the Company provided for herein shall be in writing and shall be deemed to have been duly given if delivered personally or sent by registered or certified mail, return receipt requested, postage prepaid to the following addresses or pursuant to the following email addresses, or, in the case of the Investor or any Account, the address provided in Exhibit G (or such other address as either party shall have specified by notice in writing to the other):

Karyopharm Therapeutics Inc.

85 Wells Avenue, Suite 210,

Newton, MA 02459

Attention: Chief Legal Officer and Chief

Financial Officer

Email: [***];[***]

Binding Effect. The provisions of this Exchange Agreement shall be binding upon and accrue to the benefit of the parties hereto and their respective heirs, legal representatives, successors and permitted assigns.

Notification of Changes. After the date of this Exchange Agreement until the Closing, each of the Company and the Investor (for itself and, if applicable, on behalf of each Account) hereby covenants and agrees to notify the other upon the occurrence of any event prior to the Closing that would cause any representation, warranty, or covenant of the Company or the Investor (and/or such Account), as the case may be, contained in this Exchange Agreement to be false or incorrect in any material respect.

Reliance by Exchange Advisors. The Exchange Advisors may rely on each representation and warranty of the Company and the Investor made herein or pursuant to the terms hereof (including, without limitation, in any officer’s certificate delivered pursuant to the terms

Severability. If any term or provision (in whole or in part) of this Exchange Agreement is invalid, illegal or unenforceable in any jurisdiction, such invalidity, illegality or unenforceability shall not affect any other term or provision of this Exchange Agreement or invalidate or render unenforceable such term or provision in any other jurisdiction.

Survival. The representations and warranties of the Company and the Investor contained in this Exchange Agreement, and the provisions of Section 7(e), shall survive the consummation of the transactions contemplated hereby.

Termination. This Exchange Agreement may be terminated and the transactions contemplated hereby abandoned (a) by mutual agreement of the Company and the Investor in writing or (b) by either the Company or the Investor if the conditions to such party’s obligations set forth herein have not been satisfied (unless waived by the party entitled to the benefit thereof), and the Exchange has not occurred on or before the Cutoff Date without liability of either the Company or the Investor, as the case may be; provided that neither the Company nor the Investor shall be released from liability hereunder if this Exchange Agreement is terminated and the transactions abandoned by reason of the failure of the Company or the Investor or an Exchanging Holder, as the case may be, to have performed its obligations hereunder. Except as provided above, if this Exchange Agreement is terminated and the transactions contemplated hereby are not concluded as described above, this Exchange Agreement will become void and of no further force and effect.

Tax Treatment.

The Company and the Investor hereby agree to treat, for U.S. federal income tax purposes, the exchange of the Old Notes and Old Warrants for the New Notes and New Warrants as a tax-free recapitalization and not giving rise to any deemed or constructive distribution or dividend and any payments of cash or PIK Interest (as defined in the New Notes Indenture) under New Notes as not constituting “contingent interest” for purposes of Section 871(h)(4) of the Code (or dividends or deemed dividends for U.S. tax purposes). The parties hereto agree to report all income tax matters with respect to the New Notes and New Warrants consistent with this Section 26 and shall not take any action or file any tax return, report or declaration inconsistent herewith unless required to do so by a change in applicable requirements of law or by a tax authority following an audit or examination.

Prior to making any tax reporting (e.g., IRS Form 8937, OID reporting and issue price reporting) or undertaking a change of control or similar transaction, in each case, that may impact the tax treatment of the investors regarding the exchange and the ownership and disposition of the New Notes and New Warrants, the Company will give prior notice to, and consider in good faith any input from, the Investor, provided that the Company shall not be responsible for undertaking any tax analysis regarding the potential impact of any such tax reporting, change of control or similar transaction on the Investor or on behalf thereof.

It is intended that New Notes will be treated as indebtedness (and not as equity or a “contingent payment debt instrument” governed by Section 1.1275-4 of Treasury Regulations) for federal income tax purposes and that any physical settlement of a New Note will be treated as a tax-free transaction for federal income tax purposes.

It is intended that any cashless exercise of the New Warrants, if applicable, will be treated as a tax-free transaction.

Name of
Exchanging

Holder (i.e.,

Beneficial Owner)

Aggregate

Principal

Amount of

Exchanged Old Notes

Aggregate

Principal

Amount of

Exchanged New Notes

Number of Old

Warrants

Number of New

Warrants

[●]

Total:

The following representation will be provided as applied to the Investor (or Account(s) of such Investor, if applicable):

record ownership under Clause 1 of Paragraph C below.

The following representations will be provided as applied to the partners, members or beneficial owners claiming the portfolio interest exemption:

beneficial ownership under Clause 1 of Paragraph C below,

the status in Clause 3 of Paragraph C below, and

the status in Clause 4 of Paragraph C below.

The following representation will be provided as applied to the Investor (or Account(s) of such Investor, if applicable) as well as the partners, members or beneficial owners claiming the portfolio interest exemption:

It is the sole record and beneficial owner of Old Notes in respect of which it is providing this certification.

It is not a “bank” (within the meaning of Section 881(c)(3)(A) of the Code).

It is not a “10-percent shareholder” of the Company (within the meaning of Section 881(c)(3)(B) or Section 871(h)(3)(B) of the Code).

It is not a “controlled foreign corporation” (as such term is described in Section 881(c)(3)(C) of the Code) related to the Company (within the meaning of Section 864(d)(4) of the Code).