XML 81 R53.htm IDEA: XBRL DOCUMENT v3.23.1
Stockholders' Equity - Additional Information (Details)
 1 Months Ended 12 Months Ended 70 Months Ended
Feb. 03, 2021
USD ($)
Investor
$ / shares
shares
Mar. 27, 2020
USD ($)
shares
Oct. 31, 2018
shares
Dec. 31, 2022
USD ($)
$ / shares
shares
Dec. 31, 2021
USD ($)
$ / shares
shares
Dec. 31, 2022
USD ($)
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Common stock, shares authorized       200,000,000 200,000,000 200,000,000
Common stock, par value | $ / shares       $ 0.0001 $ 0.0001 $ 0.0001
Preferred stock, shares authorized       10,000,000   10,000,000
Preferred stock, par value | $ / shares       $ 0.0001   $ 0.0001
Common stock, shares outstanding       34,414,149 29,455,668 34,414,149
Number of shares available for issuance       8,178,936 6,549,848 8,178,936
Aggregate intrinsic value of stock options exercised | $       $ 0 $ 400,000  
Proceeds from exercise of stock options | $       0 891,000  
Fair value of stock options vested | $       $ 4,500,000 $ 3,000,000.0  
Weighted-average grant-date fair value of options granted | $ / shares       $ 2.49 $ 3.94  
Unrecognized compensation expense related to unvested stock options | $       $ 6,700,000   $ 6,700,000
Expected recognition period of unrecognized compensation expense       2 years 7 months 6 days    
Dividends paid | $       $ 0    
Equity Unit Purchase Agreements            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Gross proceeds from issuance of common stock | $ $ 30,000,000.0          
Proceeds from issuance of common stock | $ $ 29,900,000          
Number of institutional investors | Investor 2          
Shares upon exercise of warrants 1,285,713          
Purchase Agreement | Lincoln Park Capital Fund, LLC            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Purchase agreement expiration date       May 01, 2023    
Common Stock | Equity Unit Purchase Agreements            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Issuance of common stock, Shares 4,285,710          
Common Stock | Purchase Agreement | Lincoln Park Capital Fund, LLC            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Issuance of common stock, Shares   65,374   0    
Stock issuance costs | $   $ 400,000        
Estimated maximum amount of common stock issuable | $   $ 15,000.0        
Term of purchase agreement   36 months        
Fair market value of commitment shares | $   $ 200,000        
Common Stock Warrants            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Number of shares available for issuance       1,366,141 1,366,141 1,366,141
Common Stock Warrants | Equity Unit Purchase Agreements            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Sale of stock, price per share | $ / shares $ 25.00          
Gross proceeds from issuance of common stock | $ $ 25,000,000          
Warrants exercisable, per share exercise price | $ / shares $ 14.00          
2018 Equity Incentive Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Equity incentive plan description       The number of shares of common stock reserved for issuance under the 2018 Plan will automatically increase on January 1 of each calendar year through January 1, 2028, in an amount equal to 5.0% of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the Board.    
2018 Equity Incentive Plan | Maximum            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Number of shares available for issuance       784,331   784,331
2018 Equity Incentive Plan | Common Stock Options            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Minimum options exercise price as percentage of fair market value of common stock       100.00%    
Remaining vesting period       3 years    
2018 Equity Incentive Plan | Common Stock Options | Maximum            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Award expiration period       10 years    
2018 Equity Incentive Plan | Tranche One | Common Stock Options            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Vesting percentage       25.00%    
2017 Equity Incentive Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Unvested shares issued under early exercise which are subject to repurchase         43,135  
Unvested stock liability | $       $ 0 $ 53,000 $ 0
2018 Employee Stock Purchase Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Number of shares authorized for issuance under purchase rights granted to employees     343,275      
Employee stock purchase plan description       Equity Stock Purchase Plan (ESPP) whereby eligible employees may elect to withhold up to 15% of their earnings to purchase shares of the Company’s common stock at a price per share equal to the lower of (i) 85% of the fair market value of a share of the Company’s common stock on the first date of an offering or (ii) 85% of the fair market value of a share of the Company’s common stock on the date of the purchase right (purchase right). Initially, 343,275 shares of the Company’s common stock were approved for issuance under the ESPP pursuant to purchase rights granted to the Company’s employees or to employees of any of the Company’s designated affiliates. The number of shares of the Company’s common stock reserved for issuance will automatically increase on January 1 of each calendar year through January 1, 2028, by the lesser of (1) 1.0% of the total number of shares of the Company’s common stock outstanding on the last day of the calendar month before the date of the automatic increase, and (2) 343,275 shares; provided that before the date of any such increase, the Board may determine that such increase will be less than the amount set forth in clauses (1) and (2)    
Withhold Percentage of employees earnings to purchase shares of common stock     15.00%      
Minimum stock price per share as percentage of fair market value of common stock     85.00%      
Number of shares issued       138,251   307,417
Number of shares available for future issuance under employee stock purchase plan       925,963    
2018 Employee Stock Purchase Plan | Purchase Right            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Minimum stock price per share as percentage of fair market value of common stock     85.00%