Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Tables)

v3.22.2.2
Stock Based Compensation (Tables)
 9 Months Ended
Sep. 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 nine months ended September 30, 2022 and 2021 was as follows (in thousands): 
  Three Months Ended September 30, Nine Months Ended September 30,
  2022 2021 2022 2021
Research and development $ 279  $ 480  $ 931  $ 1,244 
Selling, general and administrative 452  1,278  5,780  5,036 
Total stock-based compensation $ 731  $ 1,758  $ 6,711  $ 6,280 
Summary of Option Activity A summary of option activity for the nine months ended September 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 447,022  $ 9.19  $ 6.59 
Forfeited (262,852) $ 30.14  $ 20.14 
Expired (60,876) $ 53.48  $ 35.76 
Balance at September 30, 2022 1,177,571  $ 33.62  $ 20.72  6.4
Exercisable at September 30, 2022 713,994  $ 44.28  $ 26.55  4.7
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 nine months ended September 30, 2022:
Service-based options  
Expected term of option (in years)  
5 - 6.25
Expected stock price volatility  
84.0% - 93.5%
Risk-free interest rate  
1.50% - 4.06%
Expected annual dividend yield   0%