Financial Statement Details - Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financial Statement Details [Abstract]
Accrued bonus	$ 3,105	$ 2,002
Accrued compensation	1,304	1,064
Accrued laboratory equipment, supplies and related services	1,134	640
Accrued professional and service fees	1,102	975
Accrued preclinical and clinical trial costs	509	281
Accrued franchise and sales/use taxes	220	200
Other	75	181
Accrued Liabilities Current	$ 7,449	$ 5,343