UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 12, 2025 Ultragenyx Pharmaceutical Inc. (Exact name of Registrant as Specified in Its Charter) Delaware 001-36276 27-2546083 (State or Other Jurisdiction of Incorporation) 60 Leveroni Court Novato, California 94949 (Address of Principal Executive Offices) (Zip Code) (IRS Employer Identi ...