v3.22.2.2
Stock-Based Compensation (Tables)
9 Months Ended
Sep. 30, 2022
Stock-Based Compensation [Abstract]  
Components of Stock-Based Compensation Expense

Following is the stock-based compensation expense related to common stock options, restricted common stock, common stock warrants and deferred stock units:
 
 
 
Three Months Ended
September 30,
   
Nine Months Ended
September 30,
 
 
 
2022
   
2021
   
2022
   
2021
 
 
 
in thousands
 
Research and development
 
$
216
   
$
91
   
$
595
   
$
247
 
General and administrative
   
465
     
496
     
1,591
     
1,175
 
Total stock-based compensation expense
 
$
681
   
$
587
   
$
2,186
   
$
1,422
 
Stock Option Activity

The following table summarizes the stock option activity in the Company’s equity incentive plans, including non-plan grants to Company executives, from December 31, 2021 through September 30, 2022:
 
 
 
Shares
   
Weighted Average
Exercise Price
 
Outstanding, December 31, 2021
   
4,895,561
   
$
3.14
 
Granted
   
945,000
     
1.84
 
Exercised
   
   
 
Options forfeited/cancelled
   
(195,000
)
   
2.21
 
Outstanding, September 30, 2022
   
5,645,561
   
$
2.93
 
Weighted Average Assumptions Used to Determine Fair Value of Options Granted

The fair value of all other options granted is determined using the Black-Scholes option-pricing model. The following weighted average assumptions were used:
 
 
 
Nine
Months Ended
September 30,
   
Nine
Months Ended
September 30,
 
 
 
2022
   
2021
 
Risk-free interest rate
   
1.56
%
   
0.58
%
Expected life of the options
 
5.6 years
   
6 years
 
Expected volatility of the underlying stock
   
94
%
   
91
%
Expected dividend rate
   
0
%    
0
%