Supplemental Financial Information - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Disclosure of Accrued Expenses and Other Current Liabilities [Line Items]
Research and development	$ 453	$ 133
Bonuses and other employee liabilities	600
Professional fees	506	200
Other	52	90
Total accrued expenses and other current liabilities	$ 1,611	$ 423