X0609 4 2026-06-15 0001759425 Mirum Pharmaceuticals, Inc. MIRM 0001365617 Heron Patrick J false C/O MIRUM PHARMACEUTICALS, INC. 989 E. HILLSDALE BLVD., SUITE 300 FOSTER CITY CA 94404 true false false false 0 Stock Option (right to buy) 101 2026-06-15 4 A 0 3772 0 A 2036-06-14 Common Stock 3772 3772 D Deferred Stock Units 2026-06-15 4 A 0 1980 0 A Common Stock 1980 1980 D The shares vest on the first anniversary of the grant date, provided that the option will in any case be fully vested on the date of the Issuer's 2027 annual stockholder meeting. Each deferred stock unit represents a contingent right to receive one share of the Issuer's common stock and will vest on the first anniversary of the grant date, provided that it will in any case be fully vested on the date of the Issuer's 2027 annual stockholder meeting. Each vested deferred stock unit will be paid out in the Issuer's common stock upon the earliest to occur of (i) a change in control of the Issuer and (ii) within 60 days following separation from service with the Issuer. /s/ Doug Sheehy, Attorney-in-Fact 2026-06-17