Quarterly report pursuant to Section 13 or 15(d)

Stock Plans

v3.22.2
Stock Plans
6 Months Ended
Jun. 30, 2022
Stock Plans  
Stock Plans

2.    Stock Plans

The following table summarizes our option activity:

    

    

    

Weighted

    

Weighted

Average

Average 

Remaining

Aggregate

Exercise

Option

Intrinsic

Options (in

Price per

Term

Value

thousands)

share

(in years)

(in thousands)

Outstanding at December 31, 2021

 

682

$

12.53

 

8.98

$

Granted

 

310

 

1.18

Forfeited or expired

 

(24)

 

31.21

Outstanding at June 30, 2022

 

968

$

8.43

8.81

$

Exercisable at June 30, 2022

 

557

$

13.18

8.48

$

No options to purchase common shares were granted during the three-month period ended June 30, 2022.

The following table summarizes the stock-based compensation expense recorded for awards under our stock option plans (in thousands):

Three Months Ended

Six Months Ended

(in thousands)

June 30, 

June 30, 

    

2022

    

2021

    

2022

    

2021

Research and development

$

123

$

214

$

246

$

334

Selling, general and administrative

 

94

 

233

 

197

 

361

Total stock-based compensation

$

217

$

447

$

443

$

695

We use the Black-Scholes-Merton option-pricing model with the following assumptions to estimate the fair value of our stock options:

Three Months Ended

Six Months Ended

June 30, 

 

June 30, 

 

    

2022

    

2021

    

2022

    

2021

    

Weighted-average risk-free interest rate

 

%  

%

1.5

%

0.5

%

Expected dividend payments

 

 

 

 

 

Expected holding period (years) 1

 

5.4

5.5

Weighted-average volatility factor 2

 

 

 

1.13

 

1.14

 

Estimated forfeiture rates for options granted 3

 

%  

%

5

%

30

%

(1) Expected holding period is based on historical experience of similar awards, giving consideration to the contractual terms of the stock-based awards, vesting schedules and the expectations of future employee behavior.
(2) Weighted average
(3) volatility is based on the historical volatility of our common stock.
(4) Estimated forfeiture rates are based on historical data.

As of June 30, 2022, there was approximately $0.4 million of total unrecognized compensation expense related to non-vested stock options. This expense is expected to be recognized over a weighted-average period of approximately 0.8 years.