XML 45 R35.htm IDEA: XBRL DOCUMENT v3.21.2
Stock-Based Compensation (Tables)
6 Months Ended
Jun. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Summary of Stock Option Activity

A summary of stock option activity for the six months ended June 30, 2021 is set forth below:

 

 

 

Number of
Shares
Available for
Grant

 

 

Number of
Shares
Underlying
Outstanding
Options

 

 

Weighted-
Average
Exercise
Price

 

 

Weighted-
Average
Remaining
Contractual
Term
(in years)

 

 

Aggregate
Intrinsic
Value
(in thousands)

 

Outstanding, December 31, 2020

 

 

1,739,621

 

 

 

3,706,945

 

 

$

10.90

 

 

 

7.98

 

 

$

15,126

 

Options authorized

 

 

2,287,089

 

 

 

 

 

 

 

 

 

 

 

 

 

Options granted

 

 

(1,911,472

)

 

 

1,911,472

 

 

$

15.04

 

 

 

 

 

 

 

Options exercised

 

 

 

 

 

(433,594

)

 

$

2.91

 

 

 

 

 

 

 

Options forfeited or cancelled

 

 

745,006

 

 

 

(745,006

)

 

$

14.26

 

 

 

 

 

 

 

Outstanding, June 30, 2021

 

 

2,860,244

 

 

 

4,439,817

 

 

$

12.90

 

 

 

8.20

 

 

$

4,948

 

Shares exercisable, June 30, 2021

 

 

 

 

 

1,288,596

 

 

$

8.43

 

 

 

5.20

 

 

$

4,522

 

Vested and expected to vest, June 30, 2021

 

 

 

 

 

4,439,817

 

 

$

12.90

 

 

 

8.20

 

 

$

4,948

 

Summary of Stock-Based Compensation Expense

Total stock-based compensation expense recognized was as follows (in thousands):

 

 

 

Three Months Ended June 30,

 

 

Six Months Ended June 30,

 

 

 

2021

 

 

2020

 

 

2021

 

 

2020

 

Research and development

 

$

825

 

 

$

88

 

 

$

2,413

 

 

$

174

 

General and administrative

 

 

1,834

 

 

 

263

 

 

 

3,289

 

 

 

476

 

Total stock-based compensation

 

$

2,659

 

 

$

351

 

 

$

5,702

 

 

$

650

 

Schedule of Assumptions to Estimate Fair Value of Stock Options Using Black-Scholes Option Pricing Model

The assumptions used in the Black Scholes Model to calculate stock-based compensations are as follows:

 

 

 

Three Months Ended June 30,

 

Six Months Ended June 30,

 

 

2021

 

2020

 

2021

 

2020

Fair value of common stock

 

$10.29 - $15.93

 

N/A

 

$10.29 - $16.82

 

$1.48

Expected term (years)

 

0.9 - 6.1

 

 N/A

 

0.9 - 6.1

 

6.1 - 6.8

Volatility

 

77.9% - 78.6%

 

N/A

 

77.9% - 79.8%

 

80.3% - 82.6%

Risk free rates

 

0.1% - 1.1%

 

N/A

 

0.1% - 1.1%

 

0.4% - 0.5%

Dividend rate

 

0.0%

 

N/A

 

0.0%

 

0.0%