XML 29 R18.htm IDEA: XBRL DOCUMENT
v3.25.2

Note 12 - Stock-based Compensation | 6 Months Ended
--- | ---
Jun. 30, 2025
Notes to Financial Statements |
Share-Based Payment Arrangement [Text Block] | Note 12—Stock-Based Compensation ​ Our stock option plans provide for the grant of incentive and non-qualified stock options, restricted stock awards, restricted stock units, and other stock awards to employees, non-employee directors, and consultants. Stock-based compensation is as follows:
|  | Three Months Ended |  |  | Six Months Ended |
​ |  | June 30, |  |  | June 30, |
​ |  | 2025 |  |  | 2024 |  |  | 2025 |  |  | 2024 |
​ |  | (In thousands) |
|  | ​ |  |  | ​ |  |  | ​ |  |  | ​ |
Research and development |  | $ | 915 |  |  | $ | 1,069 |  |  | $ | 1,951 |  |  | $ | 2,083 |
Selling, general and administrative |  |  | 1,150 |  |  |  | 1,699 |  |  |  | 2,567 |  |  |  | 3,343 |
Total stock-based compensation |  | $ | 2,065 |  |  | $ | 2,768 |  |  | $ | 4,518 |  |  | $ | 5,426 |
The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The following assumptions were applied to all stock option grants:
​ |  | Three Months Ended |  |  | Six Months Ended |
​ |  | June 30, 2025 |  |  | June 30, 2025 |
Estimated weighted-average fair value |  | $ | 2.57 |  |  | $ | 2.61 |
Weighted-average assumptions: |  | ​ |  |  | ​ |
Expected volatility |  |  | 101 | % |  |  | 101 | %
Expected life, in years |  |  | 7.3 |  |  |  | 7.3 |
Risk-free interest rate |  |  | 4.13 | % |  |  | 4.13 | %
Expected dividend yield |  |  | — | % |  |  | — | %
Expected volatility is based on the historical volatility of our stock price weighted by grant issuances over the reporting period. We estimated the expected life of the stock options granted using the historical exercise behavior of option holders. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. Forfeiture expense is estimated at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates. Stock option activity for all stock plans and related information is as follows:
​ |  | ​ |  |  | Weighted- |  |  | ​ |  |  | ​ |
​ |  | ​ |  |  | Average |  |  | ​ |  |  | Aggregate |
​ |  | ​ |  |  | Exercise |  |  | Remaining |  |  | Intrinsic |
​ |  | Options |  |  | Price per |  |  | Contractual Life |  |  | Value |
​ |  | Outstanding |  |  | Share |  |  | (In years) |  |  | (In thousands) |
Balance at December 31, 2024 |  |  | 16,690,882 |  |  | $ | 8.17 |  |  |  |  |  |  |  |  |
Granted |  |  | 3,296,700 |  |  |  | 3.29 |  |  |  |  |  |  |  |  |
Exercised |  |  | (26,702 | ) |  |  | 3.30 |  |  |  |  |  |  |  |  |
Forfeited |  |  | (245,766 | ) |  |  | 14.20 |  |  |  |  |  |  |  |  |
Balance at June 30, 2025 |  |  | 19,715,114 |  |  | $ | 7.28 |  |  |  | 6.4 |  |  | $ | 558 |
Vested and expected to vest at June 30, 2025 |  |  | 18,974,796 |  |  | $ | 7.44 |  |  |  | 6.3 |  |  | $ | 534 |
Exercisable at June 30, 2025 |  |  | 12,469,143 |  |  | $ | 9.63 |  |  |  | 4.9 |  |  | $ | 288 |
On June 30, 2025, annual stock options grants of approximately 3.1 million shares of common stock were awarded to eligible participants for the 2024 annual performance period under the 2017 Omnibus Incentive Compensation Plan. Of the 19.7 million common stock options outstanding as of June 30, 2025, 16.9 million shares have an exercise price per share above $3.00, which was the closing price of our stock on the Nasdaq exchange on June 30, 2025. As of June 30, 2025, there were 7.2 million unvested options outstanding that will vest over a weighted-average period of 2.8 years. The total estimated compensation expense yet to be recognized on outstanding options is $16.2 million. As of June 30, 2025, the total number of shares of common stock available for grant was 3.8 million.

X
- Definition The entire disclosure for share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (l) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (h)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/718/tableOfContent Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (h)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DisclosureTextBlockAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration