Organization and Description of Business	6 Months Ended
Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Mirum Pharmaceuticals, Inc. (the “Company”) was incorporated in the State of Delaware on May 2, 2018, and is headquartered in Foster City, California. The Company is a biopharmaceutical company focused on the identification, acquisition, development and commercialization of novel therapies for debilitating rare and orphan diseases. The Company’s product LIVMARLI® (maralixibat) oral solution (“Livmarli”), is approved for the treatment of cholestatic pruritus in patients with Alagille syndrome (“ALGS”) three months of age and older in the United States and for the treatment of cholestatic pruritus in patients with ALGS two months of age and older in Europe. The Company’s development pipeline consists of two clinical-stage product candidates, Livmarli and volixibat. The Company commenced significant operations in November 2018. The Company views its operations and manages its business as one operating segment. The Company determined its operating segment on the same basis that it uses to evaluate its performance internally. Liquidity The Company has a limited operating history, has incurred significant operating losses since its inception, and the revenue and income potential of the Company’s business and market are unproven. As of June 30, 2023, the Company had an accumulated deficit of $497.0 million and cash, cash equivalents and investments of $330.0 million. The Company believes that its cash, cash equivalents and investments of $330.0 million as of June 30, 2023, provide sufficient capital resources to continue its operations for at least twelve months from the issuance date of the accompanying unaudited condensed consolidated financial statements. In April 2023, the Company completed a convertible notes offering, as further described in Note 10, with net proceeds of $305.3 million, after deducting the initial purchasers’ discounts and commissions and offering expenses. From the net proceeds, $192.7 million was used to repurchase all future revenue interests in connection with the Company’s Revenue Interest Purchase Agreement (“RIPA”) (Note 6). Upon repurchase and the termination of the RIPA, in accordance with its terms, the previously restricted cash equivalents of $100.0 million were no longer restricted from use. The unaudited condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The unaudited condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of the Company’s research and development activities.

Organization and Description of Business

6 Months Ended

Jun. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Description of Business

1. Organization and Description of Business

Mirum Pharmaceuticals, Inc. (the “Company”) was incorporated in the State of Delaware on May 2, 2018, and is headquartered in Foster City, California. The Company is a biopharmaceutical company focused on the identification, acquisition, development and commercialization of novel therapies for debilitating rare and orphan diseases.

The Company’s product LIVMARLI® (maralixibat) oral solution (“Livmarli”), is approved for the treatment of cholestatic pruritus in patients with Alagille syndrome (“ALGS”) three months of age and older in the United States and for the treatment of cholestatic pruritus in patients with ALGS two months of age and older in Europe.

The Company’s development pipeline consists of two clinical-stage product candidates, Livmarli and volixibat. The Company commenced significant operations in November 2018.

The Company views its operations and manages its business as one operating segment. The Company determined its operating segment on the same basis that it uses to evaluate its performance internally.

Liquidity

The Company has a limited operating history, has incurred significant operating losses since its inception, and the revenue and income potential of the Company’s business and market are unproven. As of June 30, 2023, the Company had an accumulated deficit of $497.0 million and cash, cash equivalents and investments of $330.0 million. The Company believes that its cash, cash equivalents and investments of $330.0 million as of June 30, 2023, provide sufficient capital resources to continue its operations for at least twelve months from the issuance date of the accompanying unaudited condensed consolidated financial statements.

In April 2023, the Company completed a convertible notes offering, as further described in Note 10, with net proceeds of $305.3 million, after deducting the initial purchasers’ discounts and commissions and offering expenses. From the net proceeds, $192.7 million was used to repurchase all future revenue interests in connection with the Company’s Revenue Interest Purchase Agreement (“RIPA”) (Note 6). Upon repurchase and the termination of the RIPA, in accordance with its terms, the previously restricted cash equivalents of $100.0 million were no longer restricted from use.

The unaudited condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The unaudited condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of the Company’s research and development activities.