Note 10. Leases

Operating leases

The Company has facility leases for laboratory and office space under non-cancellable and cancellable operating leases with various expiration dates through 2032.

The Company paid $1.5 million in cash for operating leases, net of cash received from subleases, that is included in the operating activities section of the condensed consolidated statements of cash flows for each of the three months ended March 31, 2026 and 2025.

The weighted-average remaining lease term and the weighted-average discount rate of the Company’s operating leases were 6.15 years and 8.99%, respectively, at March 31, 2026. The weighted-average remaining lease term and the weighted-average discount rate of the Company’s operating leases were 6.39 years and 8.98%, respectively, at December 31, 2025. The weighted-average remaining lease term does not include any renewal options at the election of the Company.

The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants.

Facility leases

In September 2020, the Company entered into a lease agreement for approximately 60,000 square feet of laboratory and office space in San Diego, California, which represented a portion of a new facility that was under construction and which was subsequently amended in March 2021 to expand the rented premises by approximately 18,000 square feet (the 2020 Lease). The construction and design of the asset was the primary responsibility of the lessor. The Company was involved in certain aspects of construction and design for certain interior features and leasehold improvements that is beneficial to the Company to better suit its business needs and intended purpose of the space. The lease is accounted for as an operating lease and commenced in August 2021. In April 2022, the 2020 Lease was modified to amend the rent commencement date from February 2022 to May 2022. The 2020 Lease, as amended, has a term of 10.75 years and includes aggregate monthly payments to the lessor of approximately $51.6 million beginning in May 2023 with a rent escalation clause, and a tenant improvement allowance of approximately $16.8 million. The Company is responsible for its share of operating expenses based on actual operating expenses incurred by the landlord. The 2020 Lease is cancellable at the Company’s request after the 84th month with 12 months written notice and a lump-sum cancellation payment of $2.5 million. The termination option has not been included in the Company's operating lease assets and liabilities. As discussed in Note 2, the Company provided a letter of credit to the lessor for $408,000, which expires July 29, 2032.

In December 2021, the Company entered into a lease agreement for approximately 30,000 square feet of office and laboratory space in South San Francisco, California. The lease is accounted for as an operating lease with the associated operating lease assets and liabilities recorded upon commencement, which occurred in July 2022. The non-cancellable operating lease has an initial term of 124 months with an option to extend the lease term by 5 years at the then-current market rates and includes aggregate monthly payments to the lessor of approximately $34.4 million beginning in November 2022 with a rent escalation clause and a tenant improvement allowance of approximately $8.2 million. The renewal option has not been included in the Company's operating lease assets and liabilities. The Company is responsible for its share of operating expenses based on actual operating expenses incurred by the landlord. The construction and design of the tenant improvements was the primary responsibility of the lessor. While the Company was involved in certain aspects of construction and design for certain interior features and leasehold improvements that is beneficial to the Company to better suit its business needs and intended purpose of the space, all construction was handled directly by the landlord. The Company was not deemed to be the accounting owner of the tenant improvements prior to or after the construction period. All payments made by the Company for landlord-owned tenant improvements were recorded as prepaid rent on the condensed consolidated balance sheets prior to lease commencement and included in the operating lease asset upon lease commencement. The Company paid a security deposit of $874,000 in December 2021 that was recorded as other assets in the condensed consolidated balance sheets. In July 2025, $656,000 of the security deposit was returned to the Company per the terms of the lease agreement. As of March 31, 2026, $218,000 remains as a security deposit included in other assets in the condensed consolidated balance sheets.

In January 2024, the Company entered into an agreement to sublease the second floor of its corporate headquarters in San Diego, California (the January 2024 Sublease). Pursuant to the January 2024 Sublease, the subleased space was approximately 11,000 square feet of office space with a sublease term of three years which included an option for the subtenant to renew for an additional year and an early termination clause. In June 2025, the Company and the subtenant entered into a termination agreement that terminated the January 2024 Sublease in July 2025. In July 2024, the Company entered into an agreement to sublease the first floor of its corporate headquarters (the July 2024 Sublease). Pursuant to the July 2024 Sublease, the subleased space is approximately 18,000 square feet of office space with a sublease term of 61 months beginning in October 2024. The July 2024 Sublease includes an option for the subtenant to renew for an additional year and an early termination clause. In September 2024, the Company entered into an agreement to sublease a portion of the third floor of its corporate headquarters (the September 2024 Sublease). Pursuant to the September 2024 Sublease, the subleased space was approximately 5,000 square feet of laboratory space with a sublease term of one year, which included an option for the subtenant to renew for an additional year. In July 2025, the September 2024 Sublease was amended to: (i) add approximately 5,000 square feet of laboratory space on the third floor and approximately 11,000 square feet of office space on the second floor to the subleased space; and (ii) to extend the term of the September 2024 Sublease through December 31, 2027. The amendment to the September 2024 Sublease includes an option for the subtenant to renew for an additional year.

The Company determined the subleases to be operating leases. Therefore, the Company recognizes sublease income on a straight-line basis over the lease term in its condensed consolidated statements of operations and comprehensive loss as a reduction to lease costs because the subleases are outside of the Company's normal business operations. The Company will continue to account for the operating lease assets and related liabilities of the original lease as it did prior to the commencement of the subleases. The Company recorded a reduction to lease costs of $710,000 and $713,000 related to income from these subleases during the three months ended March 31, 2026 and 2025, respectively.