Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Research and development	$ 1,597	$ 1,924
Payroll and other employee-related expenses	7,922	8,748
Professional services fees	1,845	4,888
Accrued interest	1,464	1,356
Product revenue reserves	1,854	2,306
Accrual for employee stock purchase plan	166	183
Other	562	205
Total accrued expenses and other current liabilities	$ 15,410	$ 19,610