Leases

12 Months Ended

Dec. 31, 2019

The Company currently has operating leases for office and research laboratory space, equipment, and vehicles under agreements expiring at various dates through 2044, which include renewal options on leases which the Company is reasonably certain to exercise.

For the year ended December 31, 2019, operating lease expense was $10.8 million. For the year ended December 31, 2019, the Company paid $4.9 million for amounts included in the measurement of operating lease liabilities and recorded $21.8 million of right-of-use assets and $19.4 million of tenant improvements paid through lease incentives in exchange for new operating lease liabilities.

Commitments under finance leases are not significant.

Supplemental balance sheet information related to operating leases was as follows:



(in thousands, except year and discount rate amounts)	December 31, 2019
Operating lease ROU asset	$	33,315

Current portion of the operating lease liabilities	$	7,189
Non-current portion of the operating lease liabilities	53,531
Total operating lease liability	$	60,720

Weighted-average remaining lease terms (years)	18.2
Weighted-average discount rate	13.1		%

At December 31, 2019, the future minimum operating lease payments were as follows:



(in thousands)	Operating Lease
2020	$	9,738
2021	10,787
2022	10,459
2023	10,809
2024	10,582
Thereafter	163,266
Total lease payments	215,641
Less lease incentives	(28,939		)
Less imputed interest	(125,982		)
Total operating lease liability	$	60,720

At December 31, 2018, the future minimum operating lease payments were as follows:



(in thousands)	Operating Lease
2019	$	6,244
2020	4,063
2021	3,560
2022	3,371
2023	3,611
Thereafter	10,038
Total lease payments	$	30,887

Rent expense, including fees for utilities and common area maintenances under ASC 840 for the years ended December 31, 2018 and 2017 were $5.7 million and $3.9 million, respectively.