v3.24.1.1.u2
Equity Incentive Plans, Equity Inducement Plans, Employee Stock Purchase Plan and Stock-Based Compensation (Tables)
 3 Months Ended
Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]  
Summary of Option Activity

The following table summarizes option activity under the Company’s 2004 Plan, 2018 Plan and 2021 Plan:

 

 

 

Shares

 

 

Weighted-
Average
Exercise Price

 

Stock options outstanding at December 31, 2023

 

 

7,905,032

 

 

$

11.24

 

Granted

 

 

976,750

 

 

 

4.55

 

Exercised

 

 

(23,748

)

 

 

4.91

 

Canceled and forfeited

 

 

(108,209

)

 

 

7.83

 

Stock options outstanding at March 31, 2024

 

 

8,749,825

 

 

 

10.55

 

Stock options exercisable at March 31, 2024

 

 

5,985,449

 

 

$

12.29

 
Summary of Status and Activity of Non-vested RSUs

A summary of the status and activity of non-vested RSUs during the three months ended March 31, 2024 is as follows:

 

 

 

Number of
shares

 

 

Weighted
Average
Grant-Date
Fair Value

 

Non-vested December 31, 2023

 

 

5,244,873

 

 

$

8.31

 

Granted

 

 

2,309,030

 

 

 

4.54

 

Vested and released

 

 

(1,215,729

)

 

 

9.90

 

Canceled and forfeited

 

 

(115,625

)

 

 

8.22

 

Non-vested March 31, 2024

 

 

6,222,549

 

 

$

6.60

 
Schedule of Stock-Based Compensation Expense Recognized

Total stock-based compensation expense recognized was as follows:

 

 

 

Three Months Ended

 

 

 

 

March 31,

 

 

 

 

2024

 

 

2023

 

 

 

 

(in thousands)

 

 

Research and development expense:

 

$

3,174

 

 

$

2,821

 

 

General and administrative expense:

 

 

2,894

 

 

 

3,200

 

 

Total

 

$

6,068

 

 

$

6,021