The Company’s headquarters are located in Plano, Texas, where it leases approximately 122,000 square feet of office space, with lease terms extending through June 30, 2022 with an option to renew up to three months. The Company leases additional office and laboratory space of approximately 34,890 square feet located in Irving, Texas, with lease terms extending through October 31, 2022 with an option to renew up to six months.

The Company has elected to net the amortization of the right-of-use assets and the reduction of the lease liabilities principal in accrued direct research and other current and long-term liabilities in the consolidated statements of cash flows. During the three and nine months ended September 30, 2021, cash paid for amounts included for the measurement of lease liabilities was $0.8 million and $2.4 million, respectively. During the three and nine months ended September 30, 2021, the Company recorded operating lease expense of $0.8 million and $2.4 million, respectively.

Supplemental balance sheet information related to the Company’s operating leases is as follows:

		As of September 30,
	Balance Sheet Classification	2021			2020
		(in thousands, except for years and percentage data)
Non-current right-of-use assets	Other assets	$	3,068		$	1,167
Current lease liabilities	Other current liabilities	$	3,160		$	564
Non-current lease liabilities	Other long-term liabilities	$	57		$	705

Weighted-average remaining lease term (in years)			1.0			2.1
Weighted-average discount rate			8.1	%		9.6	%

Maturities of lease liabilities by fiscal year for the Company’s operating leases:

	As of September 30, 2021
	(in thousands)
2021 (remaining three months)	$	795
2022		2,570
Total lease payments		3,365
Less: Imputed interest		(148	)
Present value of lease liabilities	$	3,217

The Company has an additional lease of a single-tenant, build-to-suit building of approximately 327,400 square feet of office and laboratory space located in Plano, Texas with an initial lease term of 16 years. The Company entered into the lease agreement on October 15, 2019 (the 2019 Lease Agreement), and at the Company’s option, it may renew the lease for two consecutive five-year renewal periods or one ten-year renewal period. The Company does not have control of the space or the construction prior to completion of construction. Therefore, no right-of-use or lease liabilities were recorded in connection with the 2019 Lease Agreement as of September 30, 2021. Under the First Amendment to the Lease Agreement executed in May 2020, the landlord will fund the Company’s leasehold improvements up to $31.3 million, of which the Company has recorded a leasehold incentive obligation of approximately $4.1 million as other long-term liabilities as of September 30, 2021. The initial annual base rent will be determined based on the project cost, subject to an initial annual cap of approximately $13.3 million, which may increase in certain circumstances. Beginning in the third lease year, the base rent will increase 1.95% per annum each year. In addition to the annual base rent, the Company will pay for taxes, insurance, utilities, operating expenses, assessments under private covenants, maintenance and repairs, certain capital repairs and replacements, and building management fees.