10. Commitments and contingencies

Leases

In January 2023, the Company entered into a lease agreement for office and laboratory space in Cambridge, Massachusetts. The Company concluded that the lease term was three years, representing the non-cancelable lease period. The lease expired in March 2026.

In December 2021, the Company entered into a lease of office and laboratory space in Cambridge, United Kingdom. The lease has a contractual period of 10 years, cancelable by the Company on the fifth anniversary of the lease commencement date. The Company concluded that the initial lease term was five years, representing the non-cancelable lease period. In December 2025, the Company entered into a deed of variation to the lease, pursuant to which (i) the Company elected not to cancel the lease on the fifth anniversary of the lease commencement date and (ii) the annual rent was increased effective in December 2026, payable quarterly in advance following a nine-month rent-free period from December 2026 to September 2027. The Company accounted for the deed of variation as a modification to the existing lease and remeasured the right-of-use asset and lease liability based on the present value of remaining lease payments, discounted at the Company’s incremental borrowing rate, and recognized an additional right-of-use asset and lease liability of $12.4 million on the modification date. The Company has a contractual right to renew the lease for a further 10-year period, which also may be cancelled after five years.

In September 2017, the Company entered into a lease agreement for office and laboratory space in Lexington, Massachusetts, which commenced on January 1, 2018. In May 2022, the Company extended the lease, originally set to expire on December 31, 2022, through December 31, 2027.

​

From time to time, the Company may enter into finance lease agreements for property and equipment. Amortization expense related to finance lease right-of-use assets is recognized on a straight-line basis over the earlier of the useful life of the right-of-use asset or the lease term and interest expense for finance leases is recognized based on the effective interest method using the Company’s incremental borrowing rate. As of June 30, 2026 and December 31, 2025, the Company recorded finance lease right-of-use assets of $0.7 million and $0.8 million, respectively, which are included in property and equipment, net, in the condensed consolidated balance sheets. As of June 30, 2026 and December 31, 2025, the Company recorded finance lease liabilities of $0.8 million and $0.9 million, respectively, which are included in accrued expenses and other current liabilities and other long-term liabilities, as applicable, in the condensed consolidated balance sheets. As of June 30, 2026, the Company has also entered into an agreement that contains a lease for property and equipment that has not yet commenced with a contractual period of approximately two years and aggregate payments of approximately $5.2 million.

​

The components of the Company’s lease expense, which are recorded as a component of research and development expenses and general and administrative expenses in the condensed consolidated statements of operations and comprehensive loss, are as follows (in thousands):

​

​

The weighted average remaining operating lease term was 5.1 years and 1.6 years as of June 30, 2026 and 2025, respectively, and the weighted average operating lease discount rate was 6.3% and 7.7% as of June 30, 2026 and 2025, respectively. The weighted average remaining finance lease term was 3.2 years and 4.2 years as of June 30, 2026 and 2025, respectively, and the weighted average finance lease discount rate was 9.5% as of each of June 30, 2026 and 2025.

​

The following table summarizes the maturities of the Company’s lease liabilities as of June 30, 2026 (in thousands):

​

​

Other commitments

The Company has entered into various agreements with contract research organizations to provide clinical trial services, contract manufacturing organizations to provide clinical trial materials and with vendors for preclinical research studies, synthetic chemistry and other services for operating purposes. These contracts are generally cancelable at any time upon less than 90 days’ prior written notice. The Company is not contractually able to terminate for convenience and avoid any and all future obligations to these vendors. In some cases, the Company is contractually obligated to make certain minimum payments to the vendors, based on the timing of the termination notification and the exact terms of the agreement.

The Company has also entered into separate agreements with third parties which provide for various future milestone payments upon the achievement of specified development, regulatory, commercial and sales-based milestones with an aggregate total value of $105.8 million, as well as potential future royalty and other payments at percentages ranging from very low to low single digits. These additional milestone payments are contingent upon future events that are not considered probable of achievement as of June 30, 2026. As of June 30, 2026, the Company was unable to estimate the timing or likelihood of achieving any of these milestones.

Legal proceedings

From time to time, the Company or its subsidiaries may become involved in various legal proceedings and claims, either asserted or unasserted, which arise in the ordinary course of business. The Company is currently not subject to any material legal proceedings. At each reporting date, the Company evaluates whether or not a potential loss amount, or a potential range of loss, is probable and reasonably estimable under the provisions of ASC 450, Contingencies.

Indemnification obligations

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. The Company also has indemnification obligations towards members of its board of directors and officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. In addition, the Company has agreed to indemnify certain investors in limited circumstances. The maximum potential amount of future payments the Company could be required to make under these indemnification arrangements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnification obligations. The Company is not aware of any claims under indemnification arrangements, and therefore it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of June 30, 2026 and December 31, 2025.