X0508 4 2025-03-04 0001326732 Xencor Inc XNCR 0001787397 Eckert Celia C/O XENCOR, INC. 465 N HALSTEAD STREET, SUITE 200 PASADENA CA 91107 1 SVP, GENERAL COUNSEL 0 Common Stock 2025-03-04 4 A 0 21949 0 A 69247 D Stock Option (Right to Buy) 14.15 2025-03-04 4 A 0 65847 0 A 2035-03-04 Common Stock 65847 65847 D Represents restricted stock units that vest as follows: 1/3 of the shares vest on the first, second and third anniversaries of the date of grant, subject to the Reporting Person's continuous service to the Issuer on and through each applicable vesting date, inclusive. Includes the following shares acquired by the Reporting Person pursuant to the Issuer's Employee Stock Purchase Plan: 822 shares acquired on June 10, 2024 and 414 shares acquired on December 10, 2024. Includes 597 shares previously inadvertently omitted due to a clerical error. On March 7, 2024, the Reporting Person filed a Form 4 which reported that, following the transactions, the Reporting Person beneficially owned a total of 46,315 shares of Common Stock (the "Original Report"). The Original Report and the subsequent Form 4 filed by the Reporting Person on March 12, 2024 inadvertently omitted 597 shares held by the Reporting Person due to a clerical error. 25% of the shares subject to the option shall vest on the one year anniversary of March 4, 2025 (the "Vesting Commencement Date") and 1/48th of the shares shall vest monthly thereafter, such that the option shall be fully vested on the four year anniversary of the Vesting Commencement Date, subject to the Reporting Person's continuous service to the Issuer on and through each applicable vesting date, inclusive. /s/ Celia E. Eckert, Attorney-in-Fact 2025-03-05