Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	UT Southwestern License	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	Common Stock	Common Stock UT Southwestern License	Additional Paid-in Capital	Additional Paid-in Capital UT Southwestern License	Accumulated Deficit
Balance at Sep. 20, 2019	$ 0				$ 0		$ 0		$ 0
Convertible preferred stock balance, shares at Sep. 20, 2019			0	0
Convertible preferred stock balance at Sep. 20, 2019			$ 0	$ 0
Balance, shares at Sep. 20, 2019					0
Issuance of Founders Shares, shares					8,715,999
Issuance of shares of common stock		$ 980						$ 980
Issuance of shares of common stock, shares						2,179,000
Net loss	(1,115)								(1,115)
Balance at Dec. 31, 2019	$ (135)						980		(1,115)
Balance, shares at Dec. 31, 2019	10,894,999				10,894,999
Issuance of convertible preferred stock			$ 28,345	$ 95,815
Issuance of convertible preferred stock, shares			10,000,000	5,647,048
Reclassification of preferred stock tranche liability upon issuance of Series A milestone shares			$ 18,080
Conversion of Series A and Series B convertible preferred stock to common stock			$ (46,425)	$ (95,815)
Conversion of Series A and Series B convertible preferred stock to common stock, shares			(10,000,000)	(5,647,048)
Conversion of Series A and Series B convertible preferred stock to common stock	$ 142,240						142,240
Conversion of convertible to common stock, shares					17,047,378
Issuance of shares of common stock	165,854						165,854
Issuance of shares of common stock, shares					9,050,000
Issuance of restricted stock award, shares					769,058
Stock-based compensation	3,354						3,354
Net loss	(60,011)								(60,011)
Balance at Dec. 31, 2020	$ 251,302						$ 312,428		$ (61,126)
Balance, shares at Dec. 31, 2020	37,761,435				37,761,435