Income Taxes - Summary of Reconciliation of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax benefit at statutory rate	$ (27,189)	$ (20,699)
State income tax, net of federal benefit	(7,065)	(6,823)
Permanent items	348	8
Stock-based compensation	174	215
Orphan drug credit	(1,827)	(2,544)
Research and development credits	(2,489)	(863)
Uncertain tax positions	1,125	785
Change in state rate	910	74
Change in valuation allowance	36,284	28,090
Other	1,329	1,757
Total income tax expense (benefit)	$ 1,600	$ 0