Balance Sheet Components - Summary of Accrued and Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued employee related costs	$ 4,359	$ 3,420
Accrued research and development costs	1,715	2,668
Accrued professional fees	774	817
Operating lease liability	$ 207	$ 187
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherCurrentLiabilitiesMember	us-gaap:OtherCurrentLiabilitiesMember
Other	$ 93	$ 78
Total accrued and other liabilities	$ 7,148	$ 7,170