CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (59,054)	$ (29,911)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,552	1,539
Amortization and premium of marketable securities, net	1,308	(173)
Loss (gain) on sale or disposal of assets	57	(24)
(Gain) loss on fair value remeasurement of contingent consideration	(6,862)	741
Stock-based compensation expense	6,607	2,784
Changes in operating assets and liabilities:
Accounts and other receivables	75	1,306
Prepaid and other current assets	(8,485)	(1,544)
Accounts payable and accrued expenses	(862)	(750)
Litigation settlement payable	15,000
Other liabilities	3,886	(3,982)
Net cash used in operating activities	(46,778)	(30,014)
Cash flows from investing activities:
Sales and maturities of marketable securities	106,756	116,000
Purchases of marketable securities	(69,847)	(85,739)
Acquisition of property and equipment	(1,248)	(710)
Proceeds from sale or disposal of assets	0	24
Net cash provided by investing activities	35,661	29,575
Cash flows from financing activities:
Proceeds from issuance of stock from employee benefit plans	375	49
Net cash provided by financing activities	375	49
Net decrease in cash and cash equivalents	(10,742)	(390)
Cash and cash equivalents at beginning of period	39,143	43,836
Cash and cash equivalents at end of period	28,401	$ 43,446
Non-cash investing activities
Accrued construction in progress	$ 54