Mirum Pharmaceuticals, Inc. — Director's Dealing 2021

Jul 8, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Mirum Pharmaceuticals, Inc. (MIRM)
CIK: 0001759425
Period of Report: 2021-07-02

Reporting Person: Flynn James E (10% Owner, * Possible Member of 10% Group)
Reporting Person: Deerfield Mgmt HIF, L.P. (10% Owner, * Possible Member of 10% Group)
Reporting Person: Deerfield Mgmt IV, L.P. (10% Owner, * Possible Member of 10% Group)
Reporting Person: DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) (10% Owner, * Possible Member of 10% Group)
Reporting Person: Deerfield Private Design Fund IV, L.P. (10% Owner, * Possible Member of 10% Group)
Reporting Person: Deerfield Healthcare Innovations Fund, L.P. (10% Owner, * Possible Member of 10% Group)
Reporting Person: Deerfield Mgmt L.P. (10% Owner, * Possible Member of 10% Group)
Reporting Person: Deerfield Special Situations Fund, L.P. (10% Owner, * Possible Member of 10% Group)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-07-02	Common Stock	S	10599	$17.011	Disposed	155401	Indirect
2021-07-06	Common Stock	S	49239	$16.195	Disposed	106162	Indirect
2021-07-07	Common Stock	S	6837	$15.869	Disposed	99325	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1558456	Indirect
Common Stock	1724456	Indirect

Footnotes

F1: The price reported in Column 4 represents a weighted average price. The shares were sold in multiple transactions at prices ranging from $16.85 to $17.55, inclusive. The reporting persons undertake to provide to 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 sold at each separate price within the ranges set forth in footnotes 1 and 2 of this Form 4.

F2: The price reported in Column 4 represents a weighted average price. The shares were sold in multiple transactions at prices ranging from $16.185 to $16.345, inclusive.

F3: The price reported in Column 4 represents a weighted average price. The shares were sold in multiple transactions at prices ranging from $15.84 to $15.955, inclusive.

F4: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt IV, L.P. is the general partner of Deerfield Private Design Fund IV, L.P. ("Fund IV"). Deerfield Mgmt, L.P. is the general partner of Deerfield Special Situations Fund, L.P. ("Deerfield Special Situations"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. (collectively with Fund IV and Deerfield Special Situations, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt, L.P., Deerfield Mgmt IV, L.P., Deerfield Mgmt HIF, L.P. and Deerfield Management Company, L.P.

F5: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.