Leases (Tables)

3 Months Ended

Mar. 31, 2021

The components of operating lease costs were as follows (in thousands):

	THREE MONTHS ENDED MARCH 31,			THREE MONTHS ENDED MARCH 31,
	2021			2020
Operating lease costs	$	1,209		$	1,212
Short-term lease costs		6			3
Variable lease costs		669			616
Sublease income		(357	)		—
	$	1,527		$	1,831

Summary of Additional Lease Information

Additional lease information is summarized in the following table (in thousands, except lease term and discount rate):

	THREE MONTHS ENDED MARCH 31,			THREE MONTHS ENDED MARCH 31,
	2021			2020
Cash paid for amounts included in the measurement of operating lease liabilities	$	1,483		$	1,698
Weighted-average remaining lease term - operating leases (years)		8.7			9.7
Weighted-average discount rate - operating leases		10	%		10	%

Schedule of Undiscounted Cash Flows Used in Calculating the Operating Lease Liabilities and Amounts to be Received under the Sublease

Undiscounted cash flows used in calculating the Company’s operating lease liabilities and amounts to be received under the sublease at 35 CambridgePark Drive as of March 31, 2021 are as follows (in thousands):

Fiscal Year	OPERATING LEASE PAYMENTS			SUBLEASE RECEIPTS		NET OPERATING LEASE PAYMENTS
2021 (remainder of the year)		4,463			961		3,502
2022		6,123			483		5,640
2023		6,307			—		6,307
2024		6,496			—		6,496
2025		34,978			—		34,978
Total undiscounted cash flows	$	58,367		$	1,444	$	56,923
Less: Amounts representing interest		(20,206	)
Present value of lease liabilities	$	38,161