Description of Business, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss per Share Would Be Anti-dilutive (Detail) - shares
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Potentially dilutive securities 10,680,000 7,273,000
Warrants to purchase common stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Potentially dilutive securities 4,235,000 5,032,000
Common Stock Options    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Potentially dilutive securities 6,445,000 2,226,000
Common Stock Subject to Repurchase    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Potentially dilutive securities   15,000