Income Tax - Schedule of Significant Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 48,833	$ 41,203
Capitalized research and development expenses	18,086	17,007
Research credits and other state credits	13,695	12,954
Intangible assets	1,465	1,655
Reserve and accruals	641	544
Share-based compensation expense	1,369	1,253
Lease liability	290	472
Valuation allowance	(84,112)	(74,646)
Total deferred tax assets	267	442
Deferred tax liabilities:
Right of use lease assets	(267)	(442)
Total deferred tax liabilities	$ (267)	$ (442)