Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Collaboration and other revenue		$ 0	$ 150	$ 250	$ 429
Operating expenses:
Research and development expense		16,553	4,864	41,826	9,448
General and administrative expense		7,142	3,301	31,376	4,625
Total operating expenses		23,695	8,165	73,202	14,073
Loss from operations		(23,695)	(8,015)	(72,952)	(13,644)
Other income (expense):
Interest income		76	31	254	37
Interest expense (includes related party amounts of $0 for the three and nine months ended September 30, 2021 and $9 and $147 for the three and nine months ended September 30, 2020, respectively)		0	(86)	(3)	(1,387)
Change in fair value of derivative liability		0	(853)	0	(1,581)
Gain (loss) on extinguishment of long-term debt		690	(2,709)	690	(2,883)
Other income (expense)		(1)		(1)
Total other income (expense)		765	(3,617)	940	(5,814)
Consolidated net loss and comprehensive loss		$ (22,930)	$ (11,632)	$ (72,012)	$ (19,458)
Net loss per common share, basic and diluted	[1]	$ (0.68)	$ (0.13)	$ (2.13)	$ (0.13)
Weighted-average shares of common stock outstanding, basic and diluted	[1]	33,909,460	80,860,651	33,751,558	80,860,651

[1] The net loss attributable to common stockholders and related per share amounts for the three and nine months ended September 30, 2020 are based on the period from July 10, 2020 to September 30, 2020, the period where the Company had outstanding common stock (see Note 1).