0001193125-26-059332.txt : 20260219 0001193125-26-059332.hdr.sgml : 20260219 20260219160212 ACCESSION NUMBER: 0001193125-26-059332 CONFORMED SUBMISSION TYPE: 4 PUBLIC DOCUMENT COUNT: 1 CONFORMED PERIOD OF REPORT: 20260217 FILED AS OF DATE: 20260219 DATE AS OF CHANGE: 20260219 REPORTING-OWNER: OWNER DATA: COMPANY CONFORMED NAME: Poulton Stuart CENTRAL INDEX KEY: 0001942597 ORGANIZATION NAME: FILING VALUES: FORM TYPE: 4 SEC ACT: 1934 Act SEC FILE NUMBER: 001-36167 FILM NUMBER: 26654216 MAIL ADDRESS: STREET 1: 85 WELLS AVENUE CITY: NEWTON STATE: MA ZIP: 02459 ISSUER: COMPANY DATA: COMPANY CONFORMED NAME: Karyopharm Therapeutics Inc. CENTRAL INDEX KEY: 0001503802 STANDARD INDUSTRIAL CLASSIFICATION: PHARMACEUTICAL PREPARATIONS [2834] ORGANIZATION NAME: 03 Life Sciences EIN: 263931704 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 BUSINESS ADDRESS: STREET 1: 85 WELLS AVENUE STREET 2: SECOND FLOOR CITY: NEWTON STATE: MA ZIP: 02459 BUSINESS PHONE: 617-658-0600 MAIL ADDRESS: STREET 1: 85 WELLS AVENUE STREET 2: SECOND FLOOR CITY: NEWTON STATE: MA ZIP: 02459 4 1 ownership.xml 4 X0508 4 2026-02-17 0001503802 Karyopharm Therapeutics Inc. KPTI 0001942597 Poulton Stuart C/O KARYOPHARM THERAPEUTICS INC. 85 WELLS AVENUE NEWTON MA 02459 false true false false EVP, Chief Development Officer false Common Stock 2026-02-17 4 S false 378 8.63 D 99429 D This transaction was effected pursuant to a durable automatic sale instruction plan adopted by the reporting person on May 18, 2022, and represents a broker-assisted sale of shares to satisfy the payment of withholding tax liability incurred upon the vesting of restricted stock units. The sale does not represent a discretionary trade by the reporting person. /s/ Nancy Smith as Attorney-in-Fact for Stuart Poulton 2026-02-19