Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Tables)

v3.22.2
Stock Based Compensation (Tables)
 6 Months Ended
Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]  
Schedule of Stock-based Compensation Expense The amount of stock-based compensation expense recognized for the three and six months ended June 30, 2022 and 2021 was as follows (in thousands): 
  Three Months Ended June 30, Six Months Ended June 30,
  2022 2021 2022 2021
Research and development $ 365  $ 467  $ 653  $ 765 
Selling, general and administrative 304  2,607  5,327  3,757 
Total stock-based compensation $ 669  $ 3,074  $ 5,980  $ 4,522 
Summary of Option Activity A summary of option activity for the six months ended June 30, 2022 is as follows:
  Options Outstanding
  Number of shares Weighted average exercise price per share Weighted average grant date fair value per share Weighted average remaining contractual term (in years)
Balance at December 31, 2021 1,054,277  $ 44.26  $ 27.45  8.1
Granted 439,590  $ 9.29  $ 6.66 
Forfeited (168,063) $ 32.37  $ 21.64 
Expired (29,569) $ 54.12  $ 42.09 
Balance at June 30, 2022 1,296,235  $ 33.72  $ 20.82  6.8
Exercisable at June 30, 2022 707,059  $ 45.36  $ 27.01  4.8
Schedule of Fair Value Assumptions for Options
The following table shows the assumptions used to compute stock-based compensation expense for stock options with service-based vesting conditions granted under the Black-Scholes valuation model for the six months ended June 30, 2022:
Service-based options  
Expected term of option (in years)  
5 - 6.25
Expected stock price volatility  
84.0% - 86.8%
Risk-free interest rate  
1.50% - 3.61%
Expected annual dividend yield   0%