Income Tax - Schedule of Reconciliations of the Expected Statutory Federal Income Tax (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Expected income taxes benefit at federal statutory rate	$ (7,093,000)	$ (3,408,000)	$ (4,990,000)
State income taxes, net of federal benefit	(2,313,000)	(12,000)	(19,000)
Permanent items and other	592,000	169,000	49,000
Stock compensation	90,000	804,000	701,000
Research credits	(1,253,000)	(835,000)	(817,000)
Unrecognized tax benefits	500,000	334,000	327,000
Foreign rate differential	21,000	13,000	20,000
Change in tax rate	52,000	(7,000)	(49,000)
Change in valuation allowance	9,404,000	2,942,000	4,778,000
Income tax (benefit) expense	$ 0	$ 0	$ 0