X0206 3 2023-05-01 0 0001759425 Mirum Pharmaceuticals, Inc. MIRM 0001974200 Howe Jolanda C/O MIRUM PHARMACEUTICALS, INC. 950 TOWER LANE, SUITE 1050 FOSTER CITY CA 94404 0 1 0 0 SVP, Global Controller Common Stock 1769 D Stock Option (right to buy) 2.94 2029-03-11 Common Stock 57900 D Stock Option (right to buy) 6.27 2029-05-13 Common Stock 50000 D Stock Option (right to buy) 19.24 2030-01-09 Common Stock 25000 D Stock Option (right to buy) 19.19 2031-01-06 Common Stock 25000 D Stock Option (right to buy) 15.87 2032-01-05 Common Stock 22500 D Stock Option (right to buy) 19.98 2032-06-30 Common Stock 18750 D Stock Option (right to buy) 23.48 2033-01-30 Common Stock 21250 D Restricted Stock Units Common Stock 2500 D Restricted Stock Units Common Stock 3125 D Restricted Stock Units Common Stock 5315 D Performance Restricted Stock Units Common Tcok 1563 D 1/4th of the 62,500 shares originally subject to the option vested one year after February 28, 2019, and the balance of the shares vest in a series of 36 successive equal monthly installments at the end of each month thereafter. 1/4th of the shares vested one year after April 12, 2019 (the "Vesting Commencement Date") and the balance of the shares vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date. 1/4th of the shares vested one year after January 10, 2020 (the "Vesting Commencement Date") and the balance of the shares vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date. 1/4th of the shares vested one year after January 7, 2021 (the "Vesting Commencement Date") and the balance of the shares vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date. 1/4th of the shares vested one year after January 6, 2022 (the "Vesting Commencement Date") and the balance of the shares vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date. 1/4th of the shares vest one year after July 1, 2022 (the "Vesting Commencement Date") and the balance of the shares vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date. 1/4th of the shares vest one year after January 31, 2023 (the "Vesting Commencement Date) and the balance of the shares vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date. The restricted stock units vest in a series of three successive equal annual installments beginning January 6, 2023. 1,250 shares vested January 6, 2023 and the remaining 2,500 shares vest ratably on January 6, 2024 and January 6, 2025. Each restricted stock unit represents a contingent right to receive one share of common stock (or its cash equivalent, at the discretion of the Issuer). The restricted stock units vest in a series of three successive equal annual installments beginning July 1, 2023. The restricted stock units vest in a series of three successive equal annual installments beginning January 31, 2024. On March 9, 2021, the reporting person was granted performance-based restricted stock units ("PSUs"), which vest upon the satisfaction of certain performance criteria. On September 29, 2021, such performance criteria were met. 1,562 shares subject to the PSUs vested on September 29, 2021, and 1,563 shares vest on June 30, 2023. /s/ Judit Ryvkin, Attorney-in-Fact 2023-05-08