Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 4,312	$ 4,551
Accrued research and development expenses	4,285	2,258
Accrued professional fees	403	542
Accrued unvested common stock subject to repurchase	21	37
Accrued other	253	256
Total accrued expenses and other liabilities	$ 9,274	$ 7,644