T. Rowe Price Investment Management Reports 6.6% Stake in Karyopharm Therapeutics Inc.

T. Rowe Price Investment Management, Inc. has filed a Schedule 13G/A with the SEC, reporting a 6.6% ownership stake in Karyopharm Therapeutics Inc. (KPTI). As of the event date on May 31, 2026, the investment management firm beneficially owns 1,539,147 shares of common stock. The filing indicates that T. Rowe Price has sole voting and dispositive power over 786,135 of these shares. This amendment represents an increase in holdings compared to previous reports of zero ownership in this specific reporting cycle. The securities were acquired in the ordinary course of business and are not held for the purpose of influencing or changing the control of the issuer. T. Rowe Price Investment Management, Inc., based in Baltimore, Maryland, operates as an investment adviser and expressly denies beneficial ownership of these securities beyond its fiduciary capacity. This filing serves as Amendment No. 3 to their previous disclosures regarding Karyopharm Therapeutics.