XML 28 R22.htm IDEA: XBRL DOCUMENT v3.24.1.u1
Stock-Based Compensation (Tables)
 3 Months Ended
Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]  
Summary of Stock Option Activity

The following table summarizes stock option activity under the Company's equity incentive plans for the three months ended March 31, 2024:

 

 

 

 

 

 

 

 

Weighted

 

 

 

 

 

 

 

 

 

Weighted

 

 

Average

 

 

 

 

 

 

 

 

 

Average

 

 

Remaining

 

 

Aggregate

 

 

 

Number of

 

 

Exercise

 

 

Contractual

 

 

Intrinsic

 

 

 

Options

 

 

Price

 

 

Term

 

 

Value

 

 

 

 

 

 

 

 

 

(In years)

 

 

(In thousands)

 

Balance outstanding as of December 31, 2023

 

 

4,686,577

 

 

$

14.11

 

 

 

7.9

 

 

$

11,712

 

Granted

 

 

2,241,000

 

 

 

9.99

 

 

 

 

 

 

 

Exercised

 

 

(1,626

)

 

 

4.44

 

 

 

 

 

 

 

Cancelled and forfeited

 

 

(34,602

)

 

 

12.94

 

 

 

 

 

 

 

Balance outstanding as of March 31, 2024

 

 

6,891,349

 

 

$

12.78

 

 

 

8.3

 

 

$

16,139

 

Exercisable as of March 31, 2024

 

 

2,617,844

 

 

$

14.76

 

 

 

6.8

 

 

$

9,011

 
Summary of Estimated Fair Value of Stock Option Awards Granted Using Black-Scholes Option-Pricing Model

The fair value of stock option awards granted for the periods indicated was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions:

 

 

Three Months Ended
March 31,

 

 

2024

 

2023

Expected term (years)

 

5.5–6.1

 

5.5–6.1

Expected volatility

 

89.4–90.4%

 

91.6–93.2%

Risk-free interest rate

 

3.8–4.1%

 

3.4–3.8%

Expected dividend

 

—

 

—

As of March 31, 2024, total unrecognized stock-based compensation expense related to unvested stock options was $34.8 million, which is expected to be recognized over a weighted-average period of 3.0 years.

RSU and PSUs

RSUs generally vest annually over a two or three-year period. PSUs generally contain performance conditions associated with corporate goals, such as achievement of certain development milestones, that vests upon achievement over a one to three-year period.
Summary of Restricted Stock Unit Activity

The following table summarizes RSU and PSU activity for the three months ended March 31, 2024:

 

 

RSUs

 

 

PSUs

 

 

 

Number of
Shares

 

 

Weighted-Average
Grant Date Fair Value per Share

 

 

Number of
Shares

 

 

Weighted-Average
Grant Date Fair Value per Share

 

Balance outstanding as of December 31, 2023

 

 

688,382

 

 

$

10.72

 

 

 

299,168

 

 

$

5.96

 

Granted

 

 

651,950

 

 

 

9.98

 

 

 

192,000

 

 

 

9.98

 

Vested

 

 

(157,172

)

 

 

13.43

 

 

 

(159,168

)

 

 

7.00

 

Canceled

 

 

(6,614

)

 

 

10.78

 

 

 

—

 

 

 

—

 

Balance outstanding as of March 31, 2024

 

 

1,176,546

 

 

$

9.95

 

 

 

332,000

 

 

$

7.79

 

As of March 31, 2024, total unrecognized stock-based compensation expense related to RSUs and PSUs was $12.3 million, which is expected to be recognized over a weighted-average period of 1.9 years.

Stock-Based Compensation
Summary of Stock-Based Compensation Expense

The Company recorded stock-based compensation expense for the periods indicated as follows (in thousands):

 

 

Three Months Ended
March 31,

 

 

 

2024

 

 

2023

 

Research and development

 

$

2,315

 

 

$

1,486

 

General and administrative

 

 

2,683

 

 

 

2,065

 

Total stock-based compensation

 

$

4,998

 

 

$

3,551