Quarterly report pursuant to Section 13 or 15(d)

STOCK-BASED COMPENSATION - Narrative (Details)

v3.21.2
STOCK-BASED COMPENSATION - Narrative (Details) - shares
6 Months Ended
Apr. 19, 2021
Aug. 31, 2020
Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock purchase offering period     6 months
2020 Omnibus Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares authorized     9,125,000
Options | 2020 Omnibus Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares of common stock reserved for future issuance   4,500,000  
Number of additional shares authorized 4,000,000    
Options outstanding (in shares)     5,379,767
Shares available for grant     3,988,558
Options | 2009 Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options outstanding (in shares)     1,266,655
Shares available for grant     0
Options | Vical Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options outstanding (in shares)     117,180
Shares available for grant     0
Employee Stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares available for grant     2,600,000
Employee Stock | Employee Stock Purchase Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares available for grant     2,600,000
Discount from market price, purchase date     85.00%