Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Additional Information (Details)

v3.20.2
Common Stock - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended
Oct. 23, 2019
May 31, 2018
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Jan. 01, 2020
Dec. 31, 2019
Oct. 30, 2019
Jan. 31, 2019
Dec. 31, 2018
Class Of Stock [Line Items]                      
Common stock, authorized shares     150,000,000   150,000,000     150,000,000   29,000,000 21,147,115
Common stock shares modified   2,904,000                  
Fair value of common stock shares modified   $ 0.74                  
Total compensation cost of common stock shares modified   $ 2,126                  
Unrecognized compensation cost, period for recognition   3 years     2 years 10 months 24 days            
Unrecognized compensation cost related to unvested stock-based awards     $ 10,955   $ 10,955            
2019 Plan                      
Class Of Stock [Line Items]                      
Shares reserved for issuance 2,342,288           961,361        
Increase in share reserved percentage 4.00%                    
Share-based compensation, number of shares available for grant     2,422,403   2,422,403            
2019 ESPP                      
Class Of Stock [Line Items]                      
Shares reserved for issuance 234,229                    
Minimum | 2019 ESPP                      
Class Of Stock [Line Items]                      
Shares reserved for issuance                   234,229  
Increase in share reserved percentage 1.00%                    
Stock Options                      
Class Of Stock [Line Items]                      
Compensation cost recognized     $ 1,067 $ 416 $ 1,940 $ 912          
Stock Options | 2018 Plan                      
Class Of Stock [Line Items]                      
Number of options granted         1,959,411            
Stock Options | 2019 Plan                      
Class Of Stock [Line Items]                      
Number of options granted         705,072            
Weighted average grant-date fair value of stock options granted         $ 8.26 $ 3.98          
Aggregate grant-date fair value of options vested         $ 940 $ 276          
Stock Options | Minimum | 2018 Plan                      
Class Of Stock [Line Items]                      
Percentage of exercise price per share of fair market value         100.00%            
Share-based compensation, vesting period         3 years            
Stock Options | Maximum | 2018 Plan                      
Class Of Stock [Line Items]                      
Term of stock options after grant date         10 years            
Share-based compensation, vesting period         4 years            
Performance-Based Shares                      
Class Of Stock [Line Items]                      
Unrecognized compensation cost related to unvested stock-based awards, other than options     176   $ 176            
Founders                      
Class Of Stock [Line Items]                      
Unrecognized compensation cost, period for recognition         9 months 18 days            
Unrecognized compensation cost related to unvested stock-based awards     575   $ 575            
Research and Development | Stock Options                      
Class Of Stock [Line Items]                      
Compensation cost recognized     491 237 910 597          
Research and Development | Founders                      
Class Of Stock [Line Items]                      
Compensation cost recognized     124 132 248 264          
General and Administrative Expense | Stock Options                      
Class Of Stock [Line Items]                      
Compensation cost recognized     576 179 1,030 315          
General and Administrative Expense | Founders                      
Class Of Stock [Line Items]                      
Compensation cost recognized     $ 44 $ 44 $ 88 $ 88          
Voting Common Stock                      
Class Of Stock [Line Items]                      
Common stock, authorized shares     143,590,481   143,590,481     143,590,481 143,590,481    
Non-voting Common Stock                      
Class Of Stock [Line Items]                      
Common stock, authorized shares     6,409,519   6,409,519     6,409,519 6,409,519