Lease obligation

12 Months Ended

Dec. 31, 2020

Lease obligation

Lease obligation

7. Lease obligation

Operating Leases

As of December 31, 2020, the Company has leases for office and lab space at 75 and 64 Sidney Street in Cambridge, Massachusetts through November 30, 2026.

In March 2020, the Company entered into an agreement to lease additional laboratory and office space at 75 Hayden Avenue in Lexington, Massachusetts through January 31, 2031. The Company gained control of and occupied the space in November of 2020.

The Company received leasehold improvement incentives from the landlord totaling $5.3 million for the 75 and 64 Sidney Street leases. The Company also received $5.6 million of leasehold improvement incentives for the 75 Hayden Avenue lease. The leasehold improvements have been capitalized as leasehold improvements and the Company recorded the incentives as a component of its right-of-use assets and is amortizing them as a reduction of lease expense over the life of the lease.

The Company’s lease agreements require the Company to maintain a cash deposit or irrevocable letter of credit of $1.8 million payable to the landlord as security for the performance of its obligations under the leases. These amounts are recorded as restricted cash and included in deposits and other non-current assets in the accompanying consolidated balance sheets.

The following table summarizes the Company’s significant contractual obligations under operating leases as of payment due date by period at December 31, 2020:

	Total Minimum
	Lease Payments
	(in thousands)
2021	$	7,822
2022		8,469
2023		8,723
2024		8,985
2025		9,644
Thereafter		19,945
Total future minimum lease payments	$	63,588
Less: imputed interest		(15,981)
Total lease liabilities	$	47,607
Reported as:
Other current liabilities	$	4,198
Other non-current liabilities		43,409
Total lease liabilities	$	47,607

Total lease cost for operating leases of approximately $6.2 million and $5.7 million was incurred during the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, the weighted average remaining lease term was 6.8 years and the weighted average incremental borrowing rate used to determine the operating lease liabilities was 8.0%.

Total rent expense for the year ended December 31, 2018 recorded under ASC 840 Leases was approximately $4.0 million.