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2. Stock Plans
The following table summarizes our option activity:
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Weighted |
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Weighted |
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Average |
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Average |
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Remaining |
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Aggregate |
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Exercise |
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Option |
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Intrinsic |
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Options (in |
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Price per |
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Term |
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Value |
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|
thousands) |
|
share |
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(in years) |
|
(in thousands) |
Outstanding at December 31, 2021 |
|
682 |
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$ |
12.53 |
|
8.98 |
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$ |
— |
Granted |
|
310 |
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|
1.18 |
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|
Forfeited or expired |
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(24) |
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|
31.21 |
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Outstanding at June 30, 2022 |
|
968 |
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$ |
8.43 |
|
8.81 |
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$ |
— |
Exercisable at June 30, 2022 |
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557 |
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$ |
13.18 |
|
8.48 |
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$ |
— |
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):
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Three Months Ended |
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Six Months Ended |
(in thousands) |
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June 30, |
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June 30, |
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2022 |
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2021 |
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2022 |
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2021 |
Research and development |
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$ |
123 |
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$ |
214 |
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$ |
246 |
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$ |
334 |
Selling, general and administrative |
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|
94 |
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|
233 |
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|
197 |
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|
361 |
Total stock-based compensation |
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$ |
217 |
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$ |
447 |
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$ |
443 |
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$ |
695 |
We use the Black-Scholes-Merton option-pricing model with the following assumptions to estimate the fair value of our stock options:
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Three Months Ended |
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Six Months Ended |
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June 30, |
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June 30, |
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2022 |
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2021 |
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2022 |
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2021 |
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Weighted-average risk-free interest rate |
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— |
% |
— |
% |
1.5 |
% |
0.5 |
% |
Expected dividend payments |
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— |
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— |
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— |
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— |
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Expected holding period (years) 1 |
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— |
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— |
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5.4 |
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5.5 |
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Weighted-average volatility factor 2 |
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— |
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— |
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1.13 |
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1.14 |
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Estimated forfeiture rates for options granted 3 |
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— |
% |
— |
% |
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. |
| (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.
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