X0306 4 2022-02-28 0 0001503802 Karyopharm Therapeutics Inc. KPTI 0001364719 Kauffman Michael C/O KARYOPHARM THERAPEUTICS INC. 85 WELLS AVENUE NEWTON MA 02459 1 0 0 0 Common Stock 2022-02-28 4 A 0 21000 0.00 A 719983 D Common Stock 2022-02-28 4 S 0 6226 10.2375 D 713757 D Common Stock 2022-02-28 4 S 0 6226 10.2375 D 898131 I By Spouse Stock Option (right to buy) 10.33 2022-02-28 4 A 0 27000 0.00 A 2032-02-27 Common Stock 27000 27000 D Represents the award of restricted stock units ("RSUs") pursuant to the Karyopharm Therapeutics Inc. 2013 Stock Incentive Plan (the "Plan"). RSUs convert into Karyopharm Therapeutics Inc. common stock on a one-for-one basis. The RSUs vest in four equal annual installments beginning February 28, 2023. This transaction was a broker-assisted sale of shares to satisfy the payment of withholding tax liability incurred upon the vesting of restricted stock units and does not represent a discretionary trade by the reporting person. Represents the weighted average sale price. These shares were sold in multiple transactions at prices ranging from $10.24 to $10.35, inclusive. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price. This transaction was a broker-assisted sale of shares to satisfy the payment of withholding tax liability incurred upon the vesting of restricted stock units and does not represent a discretionary trade by the spouse of the reporting person. This option was granted on February 28, 2022 pursuant to the Plan. The shares underlying this option vest as to 25% of the shares on February 28, 2023, with the remaining 75% vesting in 36 equal monthly installments thereafter. /s/ Nancy Smith as Attorney-in-Fact for Michael Kauffman 2022-03-02