Stock-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2021
Schedule of expenses relating to employee and non-employee stock-based awards

The Company’s results of operations include expenses relating to stock-based awards as follows (in thousands):

Year Ended December 31, 

    

2021

    

2020

    

2019

Research and development

$

2,161

$

2,791

$

3,103

General and administrative

 

2,071

 

2,956

 

4,245

Total

$

4,232

$

5,747

$

7,348

Employee stock options  
Schedule of fair value of share-based awards to employees was estimated using Black Scholes model

Year Ended December 31, 

    

2021

    

2020

    

2019

Risk-free interest rate

0.9

%  

0.5

%  

1.9

%

Expected volatility

86.7

%  

82.7

%  

82.1

%

Expected term (in years)

6.0

6.0

6.0

 

Expected dividend yield

0

%  

0

%  

0

%