The Company leases real estate, primarily its corporate headquarters in Cambridge, Massachusetts. The Company’s leases have remaining terms ranging from less than 1 year to 10 years. Certain leases include options to renew, exercised at the Company’s sole discretion, with renewal terms that can extend the lease five years. The Company evaluated the renewal options in its leases to determine if it was reasonably certain that the renewal option would be exercised, and therefore should be included in the calculation of the operating lease assets and operating lease liabilities. 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 the renewal option related to its corporate headquarters would be exercised, however, for leases it determined the renewal option was probable to be exercised, the Company included the renewal period in the calculation of the operating lease right-of-use assets and operating lease liabilities. All of the Company’s leases qualify as operating leases. With the adoption of the new leasing standard, the Company has recorded a right-of-use asset and corresponding lease liability, by calculating the present value of future lease payments, discounted at either 9.5% or 10.5%, the Company’s incremental borrowing rates, over the expected term. The right-of-use asset is reduced by any lease incentives received and the legacy deferred rent balance.

In May 2016, the Company entered into an operating lease agreement for its corporate headquarters in Cambridge, Massachusetts, with a ten-year term that expires in February 2027. Rental payments related to the lease commenced in April 2017. In connection with this lease, the Company was entitled to cash incentives from the landlord to be used for the construction of leasehold improvements within the facility. As of January 1, 2019, the Company was entitled to $4,803 of such incentives, which were recorded as a reduction to the right-of-use asset and included as a straight-line reduction to lease expense over the lease term.

In May 2018, the Company executed an amendment to lease an additional 33,526 square feet at 50 Hampshire Street in Cambridge, Massachusetts, with a 10-year term. This additional space became available for occupancy on January 1, 2020. In December 2020, the Company entered into a sublease agreement with EQRx, Inc. (“EQRx”) to sublease the entire space for three years. The term of the sublease agreement commenced in January 1, 2020. (See Note 21).

Lease Costs	Classification	Year Ended December 31, 2019

Operating lease cost	R&D Expense		2,312
	G&A Expense		899
Variable lease costs ⁽¹⁾	R&D Expense		707
	G&A Expense		276
Total lease cost			4,194

Weighted-average remaining lease term (in months)			119.6
Weighted-average discount rate			10.5	%

Cash paid for amounts included in the measurement of the Company’s operating lease liabilities was $4,148 for the year ended December 31, 2019.

As of December 31, 2019, the maturities of the Company’s operating lease liabilities were as follows:

Year Ending December 31,
2020		3,796
2021		5,529
2022		5,385
2023		5,413
2024		5,533
Thereafter		31,827
Total future lease payments		57,483
Less: Interest		(37,553	)
Present value of future lease payments (lease liability)	$	19,930

Future minimum lease payments for the Company’s operating leases as of December 31, 2018 were as follows:

Year Ending December 31,
2019		2,546
2020		4,258
2021		5,176
2022		5,292
2023		5,376
Thereafter		37,573
	$	60,221

Prior to the adoption of ASU 2016-02 and for the years ended December 31, 2018 and 2017, the Company recognized rent expense on a straight-line basis over the lease period and recorded deferred rent expense for rent expense incurred but not yet paid. The Company also recorded deferred rent attributable to cash incentives received under its lease agreements which were amortized to rent expense over the lease term. During the years ended December 31, 2018 and 2017, the Company recognized total rent expense of $1,649 and $1,194, respectively.

In November 2014, the Company entered into an operating sublease agreement with CoStim Pharmaceuticals, Inc. (“CoStim”), a subsidiary of Novartis, for office and laboratory space that expired in March 2018 (see Note 18). The Company began to sublease this space to a third-party tenant in April 2017. Sublease payments received from a third-party tenant under a sublease that expired in March 2018 were $231 and $305 for the years ended December 31, 2018 and 2017, respectively, and were recorded as reduction of rent expense.