Ultragenyx Pharmaceutical Inc. announced on April 18, 2022, William Aliski notified Ultragenyx Pharmaceutical Inc. that he will not stand for re-election as a member of the Board of Directors of the Company upon the expiration of his current term at the Company's 2022 annual meeting of stockholders. Mr. Aliski will continue to serve as a director of the Company until the 2022 Annual Meeting. Mr. Aliski's decision to let his term expire and not to stand for re-election at the 2022 Annual Meeting is for personal reasons and not related to any disagreement with the Company on its operations, policies, or practices.