Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued employee compensation and benefits	$ 1,747	$ 1,535
Accrued research and development	1,398	60
Accrued consulting and professional services	445	189
Accrued legal services and license fee	27	578
Other	668	132
Total accrued expenses and other current liabilities	$ 4,285	$ 2,494