Seres Therapeutics, Inc. Leases Disclosure

6. Leases

The Company leases real estate, primarily laboratory, office and manufacturing space. The Company’s leases have remaining terms ranging from approximately three to seven years. Certain leases include one or more options to renew, exercisable at the Company’s sole discretion, with renewal terms that can extend the lease from approximately five years to ten years. The Company evaluated the renewal options in its leases to determine if it was reasonably certain that the renewal option would be exercised, given the Company’s current business structure, uncertainty of future growth, and the associated impact to real estate, the Company concluded that it is not reasonably certain that any renewal options would be exercised. Therefore, the operating lease assets and operating lease liabilities only contemplate the initial lease terms. All the Company’s leases qualify as operating leases.

In January 2024, the Company entered into a sublease agreement with an unrelated third party to sublease a portion of its office and laboratory space in Cambridge, Massachusetts. The term of the sublease agreement commenced in March 2024 and ends on January 13, 2030. The Company will receive lease payments over the sublease term totaling $10,400. The sublessee is obligated to pay all real estate taxes and costs related to the subleased premises, including cost of operations, maintenance, repair, replacement and property management. Sublease income is recorded as Other (expense) income, net in the Company’s consolidated statements of operations and comprehensive income (loss).

During the year ended December 31, 2024, the Company identified an indicator of impairment of its donor collection facility in Cambridge, Massachusetts, as the facility is no longer being used by the Company and is being marketed for sublease. The Company determined that this represents a significant adverse change in the extent in which the long-lived asset was being used. The Company determined that the location contains multiple asset groups for the purpose of the long-lived asset impairment assessment. The Company concluded that the carrying value of each asset group was not recoverable as it exceeded the future net undiscounted cash flows that are expected to be generated from the assets within the asset group. In the first quarter of 2024, the Company recognized an impairment loss of $3,267, consisting of $1,731 on the operating lease right-of-use asset and $1,536 on the leasehold improvements. $2,727 of the total impairment loss is included in research and development expenses and the remaining $540 is included in general and administrative expenses in the accompanying consolidated statements of operations and comprehensive income (loss).

During the years ended December 31, 2025, 2024, and 2023, the Company made cash payments for operating leases of $19,442, $17,330 and $15,656, respectively.

As of December 31, 2025, the weighted average remaining lease term was 6.07 years and the weighted average incremental borrowing rate used to determine the operating lease liability was 13%. As of December 31, 2024, the weighted average remaining lease term was 6.98 years and the weighted average incremental borrowing rate used to determine the operating lease liability was 13%.