Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenue recognized	$ 0	$ 0	$ 3,000
Operating Expenses [Abstract]
Research and development	61,058	50,647	41,932
Selling, general and administrative	27,020	24,702	20,942
Goodwill impairment	0	9,758	0
Gain on sale of nonfinancial assets	(509)	0	0
Total operating expenses	87,569	85,107	62,874
Loss from operations	(87,569)	(85,107)	(59,874)
Nonoperating Income (Expense) [Abstract]
Interest income	219	10	273
Interest expense	(3,993)	(3,642)	(2,688)
Change in fair value of warrant and derivative liabilities	1,701	(366)	(437)
Loss on extinguishment of debt	0	0	(162)
Other income (expense)	(4,197)	426	905
Total other expense, net	(6,270)	(3,572)	(2,109)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	(93,839)	(88,679)	(61,983)
Income Tax Expense (Benefit)	28	17	148
Net loss and comprehensive loss	(93,867)	(88,696)	(62,131)
Temporary Equity Repurchase Of Convertible Preferred Stock	(2,546)	(13,943)	0
Net loss attributable to common stockholders	$ (96,413)	$ (102,639)	$ (62,131)
Net loss per share attributable to common stockholders - basic (in dollars per share)	$ (1.52)	$ (3.99)	$ (3.09)
Net loss per share attributable to common stockholders - diluted (in dollars per share)	$ (1.52)	$ (3.99)	$ (3.09)
Weighted average shares of common stock outstanding - basic (in shares)	63,526	25,749	20,077
Weighted average shares of common stock outstanding - diluted (in shares)	63,526	25,749	20,077