Accounts Payable and Other Liabilities - Schedule of Accounts Payable and Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Trade accounts payable	$ 1,604	$ 702
Accrued clinical/preclinical expenses	944	3,655
Accrued compensation and vacation	1,238	21
Other accrued liabilities	339	240
Accounts payable and other liabilities	$ 4,125	$ 4,618