Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating expenses:
Research and development (includes related party amounts of $1,023, $207, $1,676, and $207 respectively)	$ 25,770	$ 4,469	$ 56,494	$ 7,670
In-process research and development				78,897
General and administrative (includes related party amounts of $62, $156, $139, and $174, respectively)	7,060	1,813	16,732	3,955
Total operating expenses	32,830	6,282	73,226	90,522
Loss from operations	(32,830)	(6,282)	(73,226)	(90,522)
Other income (expense):
Interest income	15	429	1,075	530
Interest expense (includes related party amounts of $0, $(302), $0 and $(498), respectively)	(1,286)	(1,990)	(3,286)	(3,138)
Change in fair value of warrant liabilities (includes related party amounts of $0, $(57,754), $0 and $(59,031), respectively)		(57,776)	95	(59,060)
Change in fair value of convertible promissory notes (includes related party amounts of $0, $(732), $0, and $(1,053), respectively)		(2,486)		(4,928)
Other income (expense)	(4)	(7)	(5)	(7)
Total other income (expense)	(1,275)	(61,830)	(2,121)	(66,603)
Net loss	$ (34,105)	$ (68,112)	$ (75,347)	$ (157,125)
Net loss per share, basic and diluted	$ (1.02)	$ (9.30)	$ (2.29)	$ (22.87)
Weighted-average shares of common stock outstanding, basic and diluted	33,366,237	7,326,090	32,946,128	6,871,471