Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating costs and expenses:
Selling, general and administrative	$ 8,263	$ 12,243	$ 27,518	$ 41,515
Research and development	13,335	20,850	33,535	69,335
Total operating costs and expenses	21,598	33,093	61,053	110,850
Loss from continuing operations before other income (expense) and income taxes	(21,598)	(33,093)	(61,053)	(110,850)
Other income (expense):
Interest income, net	128	11	256	121
Other income (expense), net	(443)	9	(5,534)	(7,948)
Total other income (expense)	(315)	20	(5,278)	(7,827)
Loss from continuing operations before income taxes	(21,913)	(33,073)	(66,331)	(118,677)
Provision for income taxes from continuing operations	(16)	0	(45)	(9)
Loss from continuing operations	(21,929)	(33,073)	(66,376)	(118,686)
Income (loss) from discontinued operations, net of income taxes	4	(11)	(39)	(227)
Net loss	$ (21,925)	$ (33,084)	$ (66,415)	$ (118,913)
Basic and diluted loss per share:
Loss from continuing operations, basic (in dollars per shares)	$ (0.12)	$ (0.21)	$ (0.37)	$ (0.77)
Loss from continuing operations, diluted (in dollars per shares)	(0.12)	(0.21)	(0.37)	(0.77)
Income (loss) from discontinued operations, basic (in dollars per shares)	0.00	(0.00)	(0.00)	(0.00)
Income (loss) from discontinued operations, diluted (in dollars per shares)	0.00	(0.00)	(0.00)	(0.00)
Net loss per share, basic (in dollars per shares)	(0.12)	(0.21)	(0.37)	(0.78)
Net loss per share, diluted (in dollars per shares)	$ (0.12)	$ (0.21)	$ (0.37)	$ (0.78)
Weighted average shares outstanding, basic (in shares)	188,358,072	159,261,818	177,818,168	153,341,854
Weighted average shares outstanding, diluted (in shares)	188,358,072	159,261,818	177,818,168	153,341,854