Annual report pursuant to Section 13 and 15(d)

Common Stock - Additional Information (Details)

v3.20.4
Common Stock - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended
Oct. 23, 2019
May 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Aug. 31, 2020
Jan. 01, 2020
Oct. 31, 2019
Class Of Stock [Line Items]              
Common stock, authorized shares     150,000,000 150,000,000      
Conversion of non-voting common stock to voting common stock         1,733,904    
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 9 months 18 days        
Unrecognized compensation cost related to unvested stock-based awards     $ 9,809        
Stock Options              
Class Of Stock [Line Items]              
Compensation cost recognized     $ 4,388 $ 2,300      
Founders              
Class Of Stock [Line Items]              
Unrecognized compensation cost, period for recognition     3 months 18 days        
Unrecognized compensation cost related to unvested stock-based awards     $ 239        
Research and Development | Stock Options              
Class Of Stock [Line Items]              
Compensation cost recognized     1,989 1,304      
Research and Development | Founders              
Class Of Stock [Line Items]              
Compensation cost recognized     495 529      
General and Administrative Expense | Stock Options              
Class Of Stock [Line Items]              
Compensation cost recognized     2,399 996      
General and Administrative Expense | Founders              
Class Of Stock [Line Items]              
Compensation cost recognized     177 $ 177      
At-The-Market Offering Sales Agreement              
Class Of Stock [Line Items]              
Issuance of common stock     $ 75,000        
Issuance of common stock, Shares     0        
Two Thousand Eighteen Stock Option And Grant Plan | Stock Options              
Class Of Stock [Line Items]              
Share-based compensation unvested number of shares     0        
Number of options granted     1,959,411        
Two Thousand Eighteen Stock Option And Grant Plan | Stock Options | Minimum              
Class Of Stock [Line Items]              
Share-based compensation, vesting period     3 years        
Two Thousand Eighteen Stock Option And Grant Plan | Stock Options | Maximum              
Class Of Stock [Line Items]              
Share-based compensation, vesting period     4 years        
2019 Plan              
Class Of Stock [Line Items]              
Shares reserved for issuance 2,342,288         962,511  
Increase in share reserved percentage 4.00%            
Share-based compensation, number of shares available for grant     2,314,303        
2019 Plan | Stock Options              
Class Of Stock [Line Items]              
Number of options granted     813,172 1,340,839      
Weighted average grant-date fair value of stock options granted     $ 8.31 $ 5.24      
2019 ESPP              
Class Of Stock [Line Items]              
Compensation cost recognized     $ 18        
Shares reserved for issuance 234,229         234,229  
2019 ESPP | Minimum              
Class Of Stock [Line Items]              
Shares reserved for issuance 234,229            
Increase in share reserved percentage 1.00%            
2019 ESPP | Maximum              
Class Of Stock [Line Items]              
Payroll deduction percentage of eligible compensation     15.00%        
Employee stock purchase plan maximum annual rights to purchase common stock     $ 25        
Percentage of shares to be purchased     85.00%        
Voting Common Stock              
Class Of Stock [Line Items]              
Common stock, authorized shares     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