Syndax Pharmaceuticals Inc Leases Disclosure

5. Leases

Leases

The Company accounts for leases in accordance with ASC 842, Leases, and determines whether an arrangement is a lease at inception. Operating lease right-of-use, or ROU, assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Lease agreements with lease and non-lease components are accounted for separately. For leases that do not provide an implicit rate, the Company uses the incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Leases with an initial term of 12 months or less are not recorded on the balance sheet as the Company has elected to apply the short-term lease exemption. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

The Company identified three existing building leases under ASC 842 that are classified as operating leases. In September 2016, the Company entered into a five-year operating lease for 12,207 square feet of office space in Waltham, MA, with a lease commencement date of March 1, 2017. On August 17, 2021, the Company signed a

36-month extension to the lease for the Waltham, MA office with aggregate payments of $1.6 million, with a lease commencement date of March 1, 2022. As of December 31, 2025, the lease term has ended.

In December 2015, the Company entered into a 62-month operating lease for 4,039 square feet of space in New York, NY, which commenced on January 1, 2016. In February 2021, the Company signed an 18-month extension to the lease for the New York office, which commenced on March 1, 2021. In August 2022, the Company signed a 36-month extension to the lease for the New York office, with aggregate payments of $0.7 million, with a lease commencement date of September 1, 2022. As of December 31, 2025, the lease term has ended.

In May 2023, the Company entered into a 27-month operating lease for an additional 12,217 square feet of space in New York, NY, with aggregate payments of $1.6 million, with a lease commencement date of June 1, 2023. In October 2024, the Company signed a 36-month extension to the lease for the New York office, with aggregate payments of $2.5 million, with a lease commencement date of October 23, 2024. The Company recognized $1.5 million of ROU asset and lease liability upon the remeasurement of the lease as a result of the extension. The remaining lease term as of December 31, 2025 was 32 months.

As of December 31, 2025, the consolidated balance sheet includes a $1.3 million operating lease ROU asset and a $1.5 million ROU liability. The Company used an incremental borrowing rate of 10%-14% to calculate its lease obligations, and an increase or decrease in the rate does not have a significant impact on the ROU asset or ROU liability. The ROU asset is amortized on a straight-line basis over the remainder of the lease term. For the year ended December 31, 2025, the Company recorded approximately $0.9 million in operating lease expense and made approximately $0.8 million in lease payments.

Future minimum lease payments under the Company’s capital leases as of December 31, 2025 and 2024, were $2,244 and $9,435, respectively.