Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accounts payable - trade	$ 726	$ 492
Payroll and benefits	1,489	1,290
Inventory	965	1,143
Research and development	45	629
Royalty fees due to unrelated parties	276	226
Consulting	153	397
Rent and utilities	78	23
Audit and tax fees	57	113
Legal	152	138
Other	164	234
Total accounts payable and accrued expenses	$ 4,105	$ 4,685