Quarterly report pursuant to Section 13 or 15(d)

Equity Incentive Plans, Employee Stock Purchase Plan and Stock-Based Compensation (Tables)

v3.22.1
Equity Incentive Plans, Employee Stock Purchase Plan and Stock-Based Compensation (Tables)
3 Months Ended
Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [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

 

 

Weighted-
Average
Remaining
Contract Term
(Years)

 

 

Aggregate
Intrinsic Value
(in thousands)

 

Stock options outstanding at December 31, 2021

 

 

6,512,086

 

 

$

13.86

 

 

 

7.39

 

 

$

14,955

 

Granted

 

 

862,000

 

 

$

8.17

 

 

 

 

 

 

 

Exercised

 

 

(32,497

)

 

$

5.55

 

 

 

 

 

 

 

Canceled and forfeited

 

 

(97,893

)

 

$

13.23

 

 

 

 

 

 

 

Stock options outstanding at March 31, 2022

 

 

7,243,696

 

 

$

13.23

 

 

 

7.52

 

 

$

1,098

 

Stock options exercisable at March 31, 2022

 

 

4,140,938

 

 

$

13.08

 

 

 

6.58

 

 

$

672

 

Schedule of Employee Stock Options Valuation

For determining stock-based compensation expense, the fair-value-based measurement of each employee stock option was estimated as of the date of grant using the Black-Scholes option-pricing model with assumptions as follows:

 

 

 

Three Months Ended

 

 

 

March 31,

 

 

 

2022

 

 

2021

 

Expected term (in years)

 

6.0

 

 

5.8-6.1

 

Expected volatility

 

 

81.9

%

 

84.6%-84.9%

 

Risk-free interest rate

 

 

1.7

%

 

0.6%-1.0%

 

Expected dividend

 

 

 

 

 

 

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, 2022 is as follows:

 

 

 

Number of
shares

 

 

Weighted
Average
Grant-Date
Fair Value

 

Non-vested December 31, 2021

 

 

2,403,826

 

 

$

18.43

 

Granted

 

 

1,812,500

 

 

$

8.19

 

Vested and released

 

 

(465,731

)

 

$

17.76

 

Canceled and forfeited

 

 

(74,650

)

 

$

14.28

 

Non-vested March 31, 2022

 

 

3,675,945

 

 

$

13.55

 

Schedule of Fair Value of ESPP Shares Using Option Pricing Model

The fair value of the ESPP shares is estimated using the Black-Scholes option pricing model. For the three months ended March 31, 2022 and 2021, the fair value of ESPP shares was estimated using the following assumptions:

 

 

Three Months Ended

 

 

March 31,

 

 

2022

 

 

2021

 

Expected term (in years)

0.5

 

 

0.5

 

Expected volatility

65.9%-66.3%

 

 

72.5%-111.4%

 

Risk-free interest rate

0.1%-0.9%

 

 

 

0.1

%

Expected dividend

 

 

 

 

 

 

Schedule of Stock-Based Compensation Expense Recognized

Total stock-based compensation expense recognized was as follows:

 

 

 

Three Months Ended

 

 

 

March 31,

 

 

 

2022

 

 

2021

 

 

 

(in thousands)

 

Research and development expense:

 

$

2,613

 

 

$

1,104

 

General and administrative expense:

 

 

4,361

 

 

 

2,848

 

Total

 

$

6,974

 

 

$

3,952