Note 16. Leases

In January 2017, the Company entered into a lease agreement for 32,000 rentable square feet of office space located at 85 School Street, Watertown, Massachusetts. The lease term, which commenced in June 2017, was set to expire August 1, 2023. In August 2017, the Company entered into the First Amendment of the lease which extended the maturity date to January 31, 2024.

In November 2020, the Company entered into a lease agreement for 36,291 rentable square feet of office space on the 1st floor of the building located at 480 Pleasant Street, Watertown, Massachusetts. The lease term, which commenced in November 2020, is set to expire July 31, 2028, with lease payments being made on a monthly basis. There is also an option to extend for 2 additional periods of 5 years, which is not reasonably certain to be exercised and therefore not included in the measurement of the lease.

In March 2019, the Company entered into a lease agreement for 25,000 rentable square feet of office space in the building located at 900 Middlesex Turnpike, Billerica, Massachusetts. The lease term, which commenced in July 2019, was set to expire July 1, 2026, with an option to extend for 2 additional periods of 5 years each, and required monthly payments. In December 2021, the Company entered into the First Amendment of the lease and expanded the office space by approximately 21,902 rentable square feet and extended the maturity date to May 31, 2029 (“Expansion Premises”). The Expansion Premises has not been made available to the Company as of June 30, 2022 and is therefore not included in the table below, as the lease term for the Expansion Premises has not commenced. In July 2022, the Company entered into the Amended and Restated First Amendment to the lease which modified the lease commencement date to November 1, 2022, when the lease premises are expected to be made available to the Company. In addition, the lease expiration date of the original premises and expansion premises was amended to October 31, 2029. The annual base rent for the Expansion Premises per the lease agreement is approximately $0.4 million for the first lease year, and is subject to annual increases of 3% thereafter. The undiscounted future minimum rent obligation is approximately $2.7 million.

In December 2021, the Company entered into a lease agreement for 120,681 rentable square feet of office space located at 60 Tower Road, Waltham, Massachusetts (the “Premises”). The lease term, which commenced April 1, 2022, is set to expire September 30, 2031. At lease commencement, the classification and measurement of the lease was determined and recognized on the balance sheet. The annual base rent under the lease is approximately $4.8 million for the first lease year, which commenced July 2022, and is subject to fixed annual increases. The undiscounted future minimum rent obligation is approximately $49.3 million, and the discounted right of use asset and liability on the date of commencement, April 1, 2022, was $36.2 million. Per the lease agreement, the Company has provided a security deposit in the form of a letter of credit in the amount of approximately $0.8 million. This letter of credit is recorded as restricted cash within non-current other assets on the balance sheet.

Rent expense under the Company’s operating lease agreements was $2.0 million and $0.7 million for the three months ended June 30, 2022 and 2021. For the six months ended June 30, 2022 and 2021, rent expense was $2.6 million and $1.3 million. There

were not any financing, variable, or short term leases during the six months ended June 30, 2022 and 2021. Future minimum lease payments under these agreements are as follows as of June 30, 2022: