7. Leases

​

Operating Leases

In September 2015, the Company entered into a long-term lease agreement for laboratory and office space totaling approximately 94,000 square feet in Austin, Texas. The original lease term was 132 months beginning in December 2015 and expiring in November 2026, with monthly payments beginning in December 2016. In December 2021, the Company entered into an amendment of the Austin lease agreement, which extended the lease of the current premises through March 2033. The amendment also includes two additional office spaces (the “First Expansion Premises” and the “Second Expansion Premises”). The First Expansion Premises consists of 32,500 rentable square feet and commenced in February 2022. The Second Expansion Premises consists of 65,222 rentable square feet and commenced in September 2022. The terms of the First and Second Expansion Premises expire in March 2033. In March 2025, the Company entered into a lease agreement for additional premises of approximately 57,100 rentable square feet in Austin, Texas through March 2033 with an annual rent expense of approximately $0.9 million.

In October 2016, the Company entered into a lease directly with its landlord for laboratory and office spaces at its facilities located in San Carlos, California. The Company currently occupies approximately 136,000 square feet comprised of two office spaces (the “First Space” and the “Second Space”). The First Space covers approximately 88,000 square feet, and the Second Space totals approximately 48,000 square feet. In January 2021, the Company entered into an amendment of the lease to extend the term for 48 months to October 2027. The combined annual rent for the First Space and Second Space is $9.3 million, which commenced in October 2023. In July 2024, the Company entered into an amendment of the San Carlos lease to extend the term for 60 months to October 2032. The annual rent will be approximately $9.7 million beginning January 2025, escalating annually and may be increased if the Company elects to utilize additional tenant improvement allowances. In January 2025, the Company entered into a lease agreement for additional premises of approximately 40,700 rentable square feet in San Carlos, California, through November 2028 with an annual rent expense of approximately $1.5 million.

The Company entered into a lease agreement in November 2020 to lease 11,395 square feet of space located in South San Francisco, California over a 36-month term. The premises are used for general office, laboratory and research use. The annual lease payment started at $0.9 million and escalates annually after commencing in December 2021. In December 2022, the Company exercised the renewal option of the South San Francisco lease agreement. In January 2023, the Company entered in an amendment to extend the lease term of the South San Francisco premises by three years, through November 2026.

The Company entered into a lease agreement in September 2023 to lease 16,319 square feet of space located in Pleasanton, California over a 60-month term. The premises are used for laboratory and research use and commenced in December 2023. The annual lease payment started at $0.5 million and escalates annually.

The Company has also historically entered into leases for individual workspaces and storage spaces at various locations on both a month-to-month basis without an established lease term and, more recently for certain locations, has committed to terms approximating one to five years. For facilities without a committed lease term, the Company has elected to not recognize them as right-of-use assets on the consolidated balance sheets as they are all considered short-term leases. For individual workspaces where the committed lease term exceeds one year, the Company has recorded a right-of-use asset on the consolidated balance sheets.

For the six months ended June 30, 2025, the Company had $14.3 million in noncash operating activities related to additional right-of-use assets resulting from entering into new lease agreements and extension of existing leases under ASC, Topic 842, Leases (“ASC 842”). For the six months ending June 30, 2024, the Company had $0.6 million in noncash operating activities related to additional right-of-use assets.

The operating lease right-of-use assets are classified as noncurrent assets in the consolidated balance sheets. The corresponding lease liabilities are separated into current and long-term portions as follows:

​

​

As of June 30, 2025, the weighted-average remaining lease term was 7.10 years and the weighted-average discount rate was 7.1%.

The Company continues to recognize lease expense on a straight-line basis. The lease expense includes the amortization of the right-of-use assets with the associated interest component estimated by applying the effective interest method. For the three months  June 30, 2025 and 2024, total lease expense of $5.0 million and $3.6 million was recognized in the condensed statements of operations and comprehensive loss, respectively. For the six months June 30, 2025 and 2024, total lease expense of $9.3 million and $7.2 million was recognized in the condensed statements of operations and comprehensive loss, respectively. Cash paid for amounts in the measurement of operating lease liabilities totaled $4.8 million and $4.1 million for the three months ended June 30, 2025 and 2024, respectively. Cash paid for amounts in the measurement of operating lease liabilities totaled $9.3 million and $8.3 million for the six months ended June 30, 2025 and 2024, respectively.

The present value of the future minimum lease payments under all non-cancellable operating leases as of June 30, 2025 are as follows:

​

​