v3.22.2.2
CONDENSED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) - USD ($)
$ in Thousands
Total
Preferred Stock
Convertible preferred stock
Common stock
Additional paid-in capital
Accumulated other comprehensive income (loss)
Accumulated deficit
Beginning balance, preferred stock shares (in shares) at Dec. 31, 2020   1,931,860        
Beginning balance, common stock shares (in shares) at Dec. 31, 2020     6,743,271      
Beginning balance at Dec. 31, 2020 $ 26,026 $ 2 $ 7 $ 453,062 $ 0 $ (427,045)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock upon vesting of restricted stock units (in shares)     1,684      
Issuance of common stock upon exercise of options (in shares)     2,673      
Issuance of common stock upon exercise of options 26     26    
Issuance of common stock upon exercise of warrants (in shares)     241,866      
Issuance of common stock upon exercise of warrants 666     666    
Issuance of common stock through ATM (in shares)     400,970      
Issuance of common stock through ATM 5,713   $ 1 5,712    
Issuance of common stock under employee stock purchase plan (in shares)     411      
Issuance of common stock under Employee Stock Purchase Plan 2     2    
Conversions of convertible preferred stock (in shares)   (78,036) 78,036      
Conversions of convertible preferred stock 0          
Stock-based compensation expense 691     691    
Net loss (6,013)         (6,013)
Ending balance, preferred stock shares (in shares) at Mar. 31, 2021   1,853,824        
Ending balance, common stock shares (in shares) at Mar. 31, 2021     7,468,911      
Ending balance at Mar. 31, 2021 27,111 $ 2 $ 8 460,159 0 (433,058)
Beginning balance, preferred stock shares (in shares) at Dec. 31, 2020   1,931,860        
Beginning balance, common stock shares (in shares) at Dec. 31, 2020     6,743,271      
Beginning balance at Dec. 31, 2020 26,026 $ 2 $ 7 453,062 0 (427,045)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Net loss (20,675)          
Unrealized (loss) gain on short-term investments 0          
Ending balance, preferred stock shares (in shares) at Sep. 30, 2021   1,846,239        
Ending balance, common stock shares (in shares) at Sep. 30, 2021     8,704,780      
Ending balance at Sep. 30, 2021 29,012 $ 2 $ 9 476,721 0 (447,720)
Beginning balance, preferred stock shares (in shares) at Mar. 31, 2021   1,853,824        
Beginning balance, common stock shares (in shares) at Mar. 31, 2021     7,468,911      
Beginning balance at Mar. 31, 2021 27,111 $ 2 $ 8 460,159 0 (433,058)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock upon vesting of restricted stock units (in shares)     1,679      
Issuance of common stock upon exercise of options (in shares)     95      
Issuance of common stock upon exercise of warrants (in shares)     25,000      
Issuance of common stock upon exercise of warrants 166     166    
Issuance of common stock through ATM (in shares)     1,200,761      
Issuance of common stock through ATM 14,831   $ 1 14,830    
Conversions of convertible preferred stock (in shares)   (7,585) 7,585      
Stock-based compensation expense 754     754    
Net loss (6,034)         (6,034)
Ending balance, preferred stock shares (in shares) at Jun. 30, 2021   1,846,239        
Ending balance, common stock shares (in shares) at Jun. 30, 2021     8,704,031      
Ending balance at Jun. 30, 2021 36,828 $ 2 $ 9 475,909 0 (439,092)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock under employee stock purchase plan (in shares)     749      
Issuance of common stock under Employee Stock Purchase Plan 5     5    
Stock-based compensation expense 807     807    
Net loss (8,628)         (8,628)
Unrealized (loss) gain on short-term investments 0          
Ending balance, preferred stock shares (in shares) at Sep. 30, 2021   1,846,239        
Ending balance, common stock shares (in shares) at Sep. 30, 2021     8,704,780      
Ending balance at Sep. 30, 2021 $ 29,012 $ 2 $ 9 476,721 0 (447,720)
Beginning balance, preferred stock shares (in shares) at Dec. 31, 2021   5,571,959        
Beginning balance, common stock shares (in shares) at Dec. 31, 2021 14,597,118   14,597,118      
Beginning balance at Dec. 31, 2021 $ 54,958 $ 5 $ 15 509,791 0 (454,853)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock under employee stock purchase plan (in shares)     996      
Issuance of common stock under Employee Stock Purchase Plan 2     2    
Stock-based compensation expense 1,000     1,000    
Net loss (6,719)         (6,719)
Ending balance, preferred stock shares (in shares) at Mar. 31, 2022   5,571,959        
Ending balance, common stock shares (in shares) at Mar. 31, 2022     14,598,114      
Ending balance at Mar. 31, 2022 $ 49,241 $ 5 $ 15 510,793 0 (461,572)
Beginning balance, preferred stock shares (in shares) at Dec. 31, 2021   5,571,959        
Beginning balance, common stock shares (in shares) at Dec. 31, 2021 14,597,118   14,597,118      
Beginning balance at Dec. 31, 2021 $ 54,958 $ 5 $ 15 509,791 0 (454,853)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Net loss (21,528)          
Unrealized (loss) gain on short-term investments $ (31)          
Ending balance, preferred stock shares (in shares) at Sep. 30, 2022   5,571,959        
Ending balance, common stock shares (in shares) at Sep. 30, 2022 16,840,261   16,840,261      
Ending balance at Sep. 30, 2022 $ 39,670 $ 5 $ 17 516,060 (31) (476,381)
Beginning balance, preferred stock shares (in shares) at Mar. 31, 2022   5,571,959        
Beginning balance, common stock shares (in shares) at Mar. 31, 2022     14,598,114      
Beginning balance at Mar. 31, 2022 49,241 $ 5 $ 15 510,793 0 (461,572)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock upon vesting of restricted stock units (in shares)     36,300      
Stock-based compensation expense 420     420    
Net loss (7,258)         (7,258)
Unrealized (loss) gain on short-term investments (36)       (36)  
Ending balance, preferred stock shares (in shares) at Jun. 30, 2022   5,571,959        
Ending balance, common stock shares (in shares) at Jun. 30, 2022     14,634,414      
Ending balance at Jun. 30, 2022 42,367 $ 5 $ 15 511,213 (36) (468,830)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock through ATM (in shares)     2,205,100      
Issuance of common stock through ATM 4,488   $ 2 4,486    
Issuance of common stock under employee stock purchase plan (in shares)     747      
Issuance of common stock under Employee Stock Purchase Plan 1     1    
Stock-based compensation expense 360     360    
Net loss (7,551)         (7,551)
Unrealized (loss) gain on short-term investments $ 5       5  
Ending balance, preferred stock shares (in shares) at Sep. 30, 2022   5,571,959        
Ending balance, common stock shares (in shares) at Sep. 30, 2022 16,840,261   16,840,261      
Ending balance at Sep. 30, 2022 $ 39,670 $ 5 $ 17 $ 516,060 $ (31) $ (476,381)