CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (141,429)	$ (112,325)	$ (70,511)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,008	2,896	3,068
Amortization and premium of marketable securities, net	(6,222)	844	(3,209)
Loss (gain) on sale or disposal of assets		2	(24)
Intangible asset impairment			3,500
Gain on fair value remeasurement of contingent consideration		(6,862)	(1,405)
Non-cash income tax benefit			(227)
Stock-based compensation expense	23,890	15,611	8,953
Changes in operating assets and liabilities:
Accounts and other receivables	(2,281)	(175)	1,574
Prepaid and other current assets	5,900	(9,572)	(1,871)
Other assets	(3)		(5)
Accounts payable and accrued expenses	9,384	3,123	3,653
Other liabilities	462	2,726	(4,405)
Net cash used in operating activities	(107,291)	(103,732)	(60,909)
Cash flows from investing activities:
Sales and maturities of marketable securities	320,597	280,666	174,947
Purchases of marketable securities	(424,561)	(188,965)	(389,881)
Acquisition of property and equipment	(1,818)	(1,828)	(1,249)
Proceeds from sale or disposal of assets		69	27
Net cash (used in) provided by investing activities	(105,782)	89,942	(216,156)
Cash flows from financing activities:
Net proceeds from stock issuances	216,222		269,893
Proceeds from issuance of stock from employee benefit plans	2,236	4,076	2,479
Net cash provided by financing activities	218,458	4,076	272,372
Net increase (decrease) in cash and cash equivalents	5,385	(9,714)	(4,693)
Cash and cash equivalents at beginning of period	29,429	39,143	43,836
Cash and cash equivalents at end of period	34,814	29,429	39,143
Non-cash investing activities
Accrued construction in progress	$ 77	$ 113	$ 289