In August 2015, the Company entered into an operating lease agreement with U.S. REIF Central Plaza Massachusetts, LLC (the “Landlord”) with respect to its corporate headquarters located at 675 Massachusetts Avenue, Cambridge, Massachusetts (the “Original Lease”). The term of the Original Lease commenced in January 2016 and was scheduled to expire in December 2020. Under the terms of the Original Lease, the Company provided a security deposit of $0.2 million to the Landlord, which is included in long-term assets in the accompanying condensed consolidated balance sheets. The Original Lease provided for annual rent escalations as well as tenant incentives in the amount of $0.7 million, of which $0.3 million would be reimbursed to the Landlord over the initial term of the Original Lease.

On January 17, 2018, the Company entered into an amendment to the Original Lease (the “Amendment”). The Amendment made certain modifications to the Original Lease, including the addition of approximately 7,800 square feet of office space in the same building (the “Expansion Premises”) and an extension of the expiration date of the Original Lease to seven years, or December 2025. The Amendment also provided for $0.4 million from the Landlord for leasehold improvements on the Expansion Premises.

On December 16, 2019, the Company entered into a second amendment to the Original Lease and the Amendment (the “Second Amendment”). The Second Amendment made certain modifications, including (i) the addition of approximately 7,800 square feet of office space in the same building (the “Second Expansion Premises”) with a term beginning in June 2020, and (ii) an extension of the expiration date of all existing leases through May 2027.

Under the Second Amendment, the Company has two consecutive options to extend the Lease Term for an additional period of five years (the “Option Terms”), subject to certain conditions, upon notice to the Landlord. These renewal options were not included in the calculation of the operating lease assets and operating lease liabilities, as the renewal is not reasonably certain. The Second Amendment provides for annual base rent for the Second Expansion Premises of approximately $0.6 million in the first year of the Lease Term, which increases on an annual basis to approximately $0.7 million in the final year of the Lease Term, and annual base rent during the Option Terms to be calculated based on the Landlord’s good faith determination of 100% of the fair market rate for such Option Terms. The Company is also obligated to pay the Landlord certain costs, taxes and operating expenses, subject to certain exclusions. The Amendment also provides for $0.6 million from the Landlord for leasehold improvements on the Expansion Premises.

On May 4, 2020, the Company entered into a third amendment to the Original Lease, as amended by the Second Amendment (the “Third Amendment”). The Third Amendment made certain modifications, including (i) amending the commencement date of the Second Expansion Premises with a term which began in August 2020, and (ii) an extension of the expiration date of all existing leases through July 2027.

For the years ended December 31, 2021 and 2020, the components of operating lease expense were as follows (in thousands):



Operating lease expense	Statement of Operations Location	December 31, 2021		December 31, 2020
Fixed operating lease expense	Research and development expense	$	869	$	808
	General and administrative expense		681		418

Variable operating lease expense	Research and development expense		76		89
	General and administrative expense		143		58

Total operating lease expense		$	1,769	$	1,373

Supplemental cash flow information related to the Company’s operating leases for the years ended December 31, 2021 and 2020, was as follows (in thousands):


	December 31, 2021		December 31, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	1,525	$	1,171
Non-cash amounts resulting from the measurement of the lease liabilities:
Right-of-use asset and lease obligation recorded upon commencement or amendment of lease agreements		-		2,626

As part of our agreement with Meiji Seika Pharma Co. Ltd. (“Meiji”), the Company paid Meiji approximately $1.6 million during the year ended December 31, 2018, related to fixed assets which will be used in manufacturing related activities at Meiji. The Company determined this equipment to be an embedded finance lease and has been capitalized as property and equipment in the consolidated balance sheet as of December 31, 2021 and 2020. As this equipment was fully paid in 2018, there is no corresponding lease liability as of December 31, 2021 or 2020.

The following table presents the lease balances within the consolidated balance sheet, weighted average remaining lease term, and the weighted average discount rates related to the Company’s operating and finance leases as of December 31, 2021 and 2020 (in thousands, except for the weighted average remaining lease term and the weighted average discount rate):


Lease Assets and Liabilities	Classification	December 31, 2021			December 31, 2020
Assets
Operating	Operating lease right-of-use assets	$	6,530		$	7,114
Financing	Property and equipment, net		468			736
Total leased assets		$	6,998		$	7,850

Liabilities
Current
Operating	Operating lease liabilities	$	1,362		$	947
Non-Current
Operating	Non-current operating lease liabilities		5,973			6,891
Total lease liabilities		$	7,335		$	7,838

Weighted average remaining lease term (in years)			5.6			6.6
Weighted average discount rate			9.8	%		9.8	%

The following table presents the maturity of the Company’s operating lease liabilities as of December 31, 2021 (in thousands):


Years Ending December 31,
2022	$	1,362
2023		1,690
2024		1,718
2025		1,746
2026		1,956
Thereafter		1,155
Total future minimum lease payments		9,627
Less imputed interest		(2,292	)
Total operating lease liabilities	$	7,335