Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Collaboration revenue - related party	$ 6,169	$ 3,594	$ 8,094	$ 6,929
Operating expenses:
Research and development	23,180	15,513	43,125	29,719
General and administrative	6,851	6,766	14,203	12,781
Restructuring charges	1,520		1,520
Total operating expenses	31,551	22,279	58,848	42,500
Loss from operations	(25,382)	(18,685)	(50,754)	(35,571)
Other income (expense), net	290	(10)	334	(24)
Net loss	$ (25,092)	$ (18,695)	$ (50,420)	$ (35,595)
Net loss per share attributable to common stockholders, basic	$ (0.22)	$ (0.17)	$ (0.45)	$ (0.35)
Net loss per share attributable to common stockholders, diluted	$ (0.22)	$ (0.17)	$ (0.45)	$ (0.35)
Weighted average shares of common stock outstanding, basic	112,859,461	112,298,982	112,735,101	100,850,878
Weighted average shares of common stock outstanding, diluted	112,859,461	112,298,982	112,735,101	100,850,878