Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Tables)

v3.23.3
Stock-Based Compensation (Tables)
9 Months Ended
Sep. 30, 2023
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Stock-Based Compensation Expense

Stock-based compensation expense, which consists of the compensation cost for employee stock options and the value of options issued to non-employees for services rendered, was allocated to research and development and general and administrative in the consolidated statements of operations as follows (in thousands):

 

Three Months Ended
September 30,

Nine Months Ended
September 30,

 

    

2023

    

2022

    

2023

    

2022

Research and development

$

353

$

1,381

$

2,411

$

4,753

General and administrative

895

1,260

2,931

4,552

Total stock-based compensation

$

1,248

$

2,641

$

5,342

$

9,305

Weighted-Average Fair Value Valuation Assumptions

The fair value of employee stock options was estimated using the following weighted-average assumptions:

 

Three Months Ended
September 30,

Nine Months Ended
September 30,

 

    

2023

    

2022

    

2023

    

2022

Employee Stock Options:

Risk-free interest rate

4.29

%  

3.25

%  

4.03

%  

2.33

%

Expected term (in years)

6.08

6.08

6.08

6.08

Dividend yield

Volatility

78.85

%  

83.32

%  

77.65

%  

88.70

%

Weighted-average fair value of stock options granted

$

5.82

$

7.95

$

5.23

$

24.90

Summary of Stock Option Activity Under Equity Incentive Plan

The following table summarizes stock option activity under the Company’s equity incentive plans:

    

Outstanding Options
Number of Shares

    

Weighted Average
Exercise Price

    

Weighted Average
Remaining
Contractual Term

    

Aggregate Intrinsic
Value (in millions):

Balances, December 31, 2021

523,411

$

153.11

6.72

$

14.25

Granted

194,679

$

33.09

Exercised

(3,106)

$

10.65

Cancelled

(152,106)

$

141.63

Balances, December 31, 2022

562,878

$

115.50

7.09

$

Granted

213,168

$

7.46

Exercised

(192)

$

7.20

Cancelled

(241,027)

$

82.61

Balances, September 30, 2023

534,827

$

87.30

6.61

$

Vested and expected to vest, September 30, 2023

534,827

$

87.30

6.61

$

Exercisable at September 30, 2023

327,184

$

118.84

5.05

$