Tango Therapeutics, Inc. Leases Disclosure

7. Leases

Operating Leases

In September 2019, the Company entered into a lease for office and laboratory space at 201 Brookline Avenue in Boston, Massachusetts. The lease, as amended and restated in November 2021, has a non-cancelable term of ten years with an option to extend for up to two additional five-year periods. The lease commenced in August 2022, when the Company obtained access to the space for its intended use. The lease agreement provides for initial tenant improvement allowances. The lease agreement required the Company to provide an initial letter of credit for $3.4 million that is collateralized with cash that is recorded as restricted cash in the accompanying balance sheets and is subject to reductions as lease anniversary dates are achieved. This letter of credit was recorded as long-term restricted cash as of December 31, 2022. In February 2024, $0.9

million of this security deposit was released to the Company, reducing the letter of credit to $2.6 million, which was classified as long-term as of December 31, 2024. As of December 31, 2025, $0.4 million was classified as short-term restricted cash to reflect the security deposit reduction scheduled for February 2026, with the remaining $2.2 million classified as long-term. The short-term portion of this security deposit was released to the Company in February 2026, further reducing the letter of credit to $2.2 million.

In August 2022, upon commencement of the 201 Brookline Avenue lease, the Company recorded an operating lease liability in the amount of $37.9 million and related operating lease right-of-use asset in the amount of $48.0 million. Payments totaling $10.1 million for tenant improvements, and net of tenant improvement allowance reimbursements, made prior to the lease commencement date were reclassified as an increase to the right-of-use asset upon the commencement of the lease. The fixed annual rent payable under the lease is $5.1 million, increasing by 3% annually from the rent commencement date. The minimum rent payments to be paid over the 10-year term of the lease total $61.0 million. The additional rental payments associated with the renewal option were not included in the calculation of the operating lease right-of-use asset and associated operating lease liability as the renewal was not considered probable of occurring. The discount rate applied to the lease payments is 8.0%.

In December 2022, the Company entered into an operating lease agreement to sublease a portion of the 201 Brookline Avenue premise to an unrelated third party. The sublease expired on December 31, 2024. In August 2025, the Company and a related party, Sesame Therapeutics, Inc. (Sesame), entered into a use and occupancy sub-lease of office and laboratory space at 201 Brookline Avenue in Boston, Massachusetts. The sub-lease will expire on December 31, 2027, with a sublessee option to extend the term for six months. Sublease income recognized under the sublease agreement for the years ended December 31, 2025, 2024, and 2023 were $0.1 million, $1.5 million, and $1.5 million, respectively, and was recorded as a reduction of the related lease expense.

The Company’s rent payments for facility leases during the years ended December 31, 2025, 2024, and 2023 are classified as operating lease costs in the table below. The leases are both considered net leases and therefore the non-lease components, such as common area maintenance, are paid separately from rent based on actual costs incurred; therefore, the non-lease components are not included in the right-of-use asset and lease liability and are reflected as an expense in the period incurred. The non-lease components are classified as variable costs in the chart below. As of December 31, 2025 and 2024, right-of-use assets under operating leases totaled $35.6 million and $39.5 million, respectively. The elements of lease cost were as follows (in thousands, unless otherwise noted):