X0508 4 2023-09-11 0 0001759425 Mirum Pharmaceuticals, Inc. MIRM 0001197350 BJERKHOLT ERIC C/O MIRUM PHARMACEUTICALS, INC. 950 TOWER LANE, SUITE 1050 FOSTER CITY CA 94404 0 1 0 0 Chief Financial Officer 0 Common Stock 2023-09-11 4 P 0 10000 29.6492 A 10000 D Stock Option (right to buy) 30.43 2023-09-11 4 A 0 110000 0.00 A 2033-09-10 Common Stock 110000 110000 D Restricted Stock Units 2023-09-11 4 A 0 55000 0.00 A Common Stock 55000 55000 D The price reported on this Form 4 is a weighted average price. The shares were purchased in multiple transactions ranging from $29.61 to $29.65, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each price within the range set forth herein. 1/4th of the shares subject to the Option will vest one year after September 11, 2023 (the "Vesting Commencement Date") and the balance of the shares will vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a series of three successive equal annual installments beginning on the one year anniversary of September 11, 2023. /s/ Judit Ryvkin, Attorney-in-Fact 2023-09-12