Note 11 - Stock-based Compensation (Tables)
|
3 Months Ended |
Mar. 31, 2023 |
|---|
| Notes To Financial Statements [Abstract] |
|
| Share-based Payment Arrangement, Option, Activity |
Stock option transactions for the three months ended March 31, 2023, and March 31, 2022, are summarized as follows:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Three months ended
March 31, 2023 |
|
|
|
|
|
|
Options (in thousands) |
|
|
Weighted average
exercise price |
|
|
Weighted average remaining contractual life
(years) |
|
Outstanding, beginning of period |
|
|
16,503 |
|
|
$ |
3.48 |
|
|
|
|
Granted |
|
|
3,220 |
|
|
0.56 |
|
|
|
|
Exercised |
|
|
— |
|
|
|
— |
|
|
|
|
Forfeited |
|
|
(884 |
) |
|
|
1.20 |
|
|
|
|
Outstanding, end of the period |
|
|
18,839 |
|
|
$ |
3.11 |
|
|
|
7.01 |
|
Exercisable, end of the period |
|
|
11,002 |
|
|
|
4.17 |
|
|
|
5.54 |
|
Vested and expected to vest, end of period |
|
|
17,426 |
|
|
$ |
3.22 |
|
|
|
6.84 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Three months ended
March 31, 2022 |
|
|
|
|
|
|
Options (in thousands) |
|
|
Weighted average
exercise price |
|
|
Weighted average remaining
contractual
life (years) |
|
Outstanding, beginning of period |
|
|
15,112 |
|
|
$ |
4.61 |
|
|
|
|
Granted |
|
|
3,870 |
|
|
1.34 |
|
|
|
|
Exercised |
|
|
(14 |
) |
|
1.08 |
|
|
|
|
Forfeited |
|
|
(349 |
) |
|
4.77 |
|
|
|
|
Outstanding, end of the period |
|
|
18,619 |
|
|
|
3.97 |
|
|
|
7.0 |
|
Exercisable, end of the period |
|
|
10,736 |
|
|
|
4.68 |
|
|
|
5.5 |
|
Vested and expected to vest, end of period |
|
|
17,344 |
|
|
$ |
4.03 |
|
|
|
6.9 |
|
|
| Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions |
The following table presents the weighted average assumptions that were used in the Black‑Scholes option pricing model to determine the fair value of stock options granted during the period, and the resulting weighted-average fair values:
|
|
|
|
|
|
|
|
|
|
|
Three months ended
March 31, 2023 |
|
|
Three months ended
March 31, 2022 |
|
Risk-free interest rate |
|
|
3.41 |
% |
|
|
1.70 |
% |
Expected dividend yield |
|
|
— |
|
|
|
— |
|
Expected volatility |
|
|
80.3 |
% |
|
|
83.3 |
% |
Expected life of options |
|
5 years |
|
|
5 years |
|
Grant date fair value |
|
$ |
0.44 |
|
|
$ |
0.89 |
|
|
| Schedule of Share-based Payment Award, Options, Grants in Period |
The following table presents the vesting terms of options granted in the period:
|
|
|
|
|
|
|
|
|
|
|
Three months ended
March 31, 2023 |
|
|
Three months ended
March 31, 2022 |
|
|
|
Number of options
(in thousands) |
|
|
Number of options
(in thousands) |
|
3-year vesting (50%-25%-25%) |
|
|
725 |
|
|
|
425 |
|
4-year vesting (50%-16 2/3%-16 2/3%-16 2/3%) |
|
|
2,495 |
|
|
|
3,445 |
|
Total stock options granted in the period |
|
|
3,220 |
|
|
|
3,870 |
|
|
| Share-based Payment Arrangement, Vesting and Redemption of the RSUs Granted |
No RSUs were granted in the three months ended March 31, 2022. The following table presents the vesting and redemption of the RSUs granted in the three months ended March 31, 2023.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Three months ended
March 31, 2023 |
|
Three months ended
March 31, 2022 |
|
|
Number of options
(in thousands) |
|
Weighted average grant date fair value |
|
Number of options
(in thousands) |
|
Weighted average grant date fair value |
|
Outstanding, beginning of period |
|
— |
|
$ |
— |
|
|
— |
|
$ |
— |
|
Granted |
|
570 |
|
|
0.66 |
|
|
— |
|
|
— |
|
Vested and redeemed |
|
(570 |
) |
|
0.66 |
|
|
— |
|
|
— |
|
Outstanding, ending of period |
|
— |
|
$ |
— |
|
|
— |
|
$ |
— |
|
|
| Share-based Payment Arrangement, Expensed and Capitalized, Amount |
The Company recorded share-based payment expense related to stock options and RSUs as follows:
|
|
|
|
|
|
|
|
|
|
|
Three months ended
March 31, |
|
|
|
2023 |
|
|
2022 |
|
Research and development |
|
$ |
652 |
|
|
$ |
946 |
|
General and administrative |
|
|
1,222 |
|
|
|
1,568 |
|
|
|
$ |
1,874 |
|
|
$ |
2,514 |
|
|