Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (18,218)	$ (18,728)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	355	154
Purchase net (premium) discount on marketable securities	(174)	19
Net amortization of premium (accretion of discount) on marketable securities	181	(48)
Stock-based compensation	1,757	1,348
Non-cash operating lease expense	108	152
Changes in operating assets and liabilities:
Accounts receivable - license	(21,500)
Prepaid expenses and other assets	(340)	(2,696)
Accounts payable	(376)	262
Operating lease liabilities	(123)	(92)
Deferred revenue	21,500
Accrued and other liabilities	(2,700)	(2,065)
Net cash used in operating activities	(19,530)	(21,694)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(450)	(1,389)
Purchases of marketable securities	(24,250)	(4,000)
Proceeds from maturities of marketable securities	34,000	20,142
Net cash provided by investing activities	9,300	14,753
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from employee stock plan purchases and stock option exercises	367	289
Principal payments on finance lease obligation	(5)	(7)
Net cash provided by financing activities	362	282
Effect of exchange rate on cash, cash equivalents, and restricted cash	7
NET DECREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	(9,861)	(6,659)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH
Beginning of period	91,937	20,753
End of period	$ 82,076	14,094
Supplemental Disclosure of Non-Cash Investing and Financing Information:
Leased assets obtained in exchange for lease obligations		137
Unpaid amounts related to purchase of property and equipment		$ 1,057