Mirum Pharmaceuticals, Inc.MIRM

Mirum Pharmaceuticals, Inc. Leases Disclosure

10-KFiled Feb 25, 20262 min read
Leases
The Company has operating leases for office spaces in various global locations, including its headquarters in Foster City, California, the lease for which was entered into in January 2024 with an initial lease term of approximately five years (the “Initial Lease”). In January 2026, the Company amended the Initial Lease (the “Amended Agreement”) to expand its headquarters office space by approximately 19,400 square feet (the “Expanded Space”) with a lease term of approximately five years from the commencement date. The Amended Agreement extends the lease term of the Initial Lease to be coterminous with the Expanded Space. The addition of the expanded space will result in approximately $10.6 million of additional base rent compared to the remaining payments of the Initial Lease.
In March 2025, the Company entered into an operating lease agreement for office space at an international location. The lease commenced in the second quarter of 2025 and has a lease term of approximately five years. In December 2025, the Company amended the terms of a lease at another international location to include additional space with a five-year lease term expiring January 2031 and a commencement date of December 2025. In addition, the amendment extended the lease term of the existing space to the same term.
The following tables contain a summary of other information and the undiscounted future minimum payments pertaining to the Company’s operating leases that had commenced as of the end of the periods presented:
December 31, 2025
Weighted-average incremental borrowing rate7.4%
Weighted-average remaining lease term (in years)4.0 years

Years Ended December 31,Undiscounted
Rent Payments
(in thousands)
2026$2,771 
20272,856 
20282,922 
20292,201 
2030351 
Thereafter21 
Total undiscounted lease payments11,122 
Less: imputed interest(1,467)
Total lease liability$9,655 
Rent expense was $2.4 million, $1.8 million and $0.8 million for the years ended December 31, 2025, 2024 and 2023, respectively. Variable lease payments for the years ended December 31, 2025, 2024 and 2023 were insignificant.

Historical Timeline

Fiscal YearFiled
2025Feb 25, 2026Showing above
2024Feb 26, 2025
2023Mar 15, 2024
2022Mar 8, 2023
2021Mar 9, 2022
2020Mar 9, 2021
2019Mar 12, 2020

About Leases Disclosures

Lease disclosures under ASC 842 provide a comprehensive view of a company's leased asset portfolio, including the split between operating and finance leases, discount rates used to present-value future payments, and the maturity schedule of lease obligations. This section reveals a significant source of off-balance-sheet commitments that were largely hidden before the current standard.

Key signals: the weighted-average discount rate affects the size of recorded lease liabilities — a higher rate reduces the reported obligation, so compare the chosen rate against the company's incremental borrowing rate. The operating versus finance lease mix affects both EBITDA and operating income presentation. Watch the maturity table for concentration risk: large payment cliffs in specific years may create cash flow pressure. Variable lease payments excluded from the liability measurement represent real obligations that do not appear on the balance sheet. Compare total lease costs against prior-year operating lease expense to assess the true economic burden.

Other Available Disclosures

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