X0508 4 2023-09-27 0 0001515673 Ultragenyx Pharmaceutical Inc. RARE 0001653052 Crombez Eric C/O ULTRAGENYX PHARMACEUTICAL INC. 60 LEVERONI COURT NOVATO CA 94949 0 1 0 0 EVP and Chief Medical Officer 0 Common Stock 30512 D Stock Option (Right to Buy) 67.37 2023-09-27 4 A 0 2351 0.00 A 2027-03-01 Common Stock 2351 2351 D Includes previously reported shares of common stock underlying Restricted Stock Units granted to the Reporting Person, which are subject to certain vesting conditions. On March 1, 2022, the Reporting Person was granted an option to purchase 2,351 shares of common stock. The option vests upon the achievement of specified performance criteria. Upon achievement of the performance criteria, 1/3 of the option vests on the date of certification by the Issuer's compensation committee of achievement of the performance criteria, 1/3 of the option vests on March 1, 2024 and 1/3 of the option vests on March 1, 2025. On September 27, 2023, the Issuer's compensation committee certified achievement of the performance criteria for the option, resulting in the vesting of the option of 784 shares on that date. /s/ Karah Parschauer, attorney-in-fact 2023-09-29