Stockholders' Equity - Shares Reserved For Future Issuances (Detail) - shares	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	55,139,084	3,646,200
Conversion of Common Stock Warrants and Prefunded Warrants [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	20,602,244
LPC Purchase Agreement [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	30,000,000
2012 Stock Option And Grant Plan [Member] | 2012 Stock Incentive Plan [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	665,720	921,824
2019 Stock Option And Grant Plan [Member] | 2019 Stock Incentive Plan [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	3,400,489	2,396,922
2019 Stock Option And Grant Plan [Member] | 2019 Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	470,631	327,454