Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Prepaid Expense And Other Assets Current [Abstract]
Tax incentive refund	$ 2,034	$ 1,916
Prepaid research and development costs	4,006	4,915
Prepaid insurance	410	897
Interest income receivable	149	224
Prepaid rent	87	86
Other current assets	966	620
Total	$ 7,652	$ 8,658