XML 22 R13.htm IDEA: XBRL DOCUMENT
v3.23.1

Stock-Based Compensation | 3 Months Ended
--- | ---
Mar. 31, 2023
Stock-Based Compensation |
Stock-Based Compensation | (8) Stock-Based Compensation ​ A summary of stock option activity for the three months ended March 31, 2023 is as follows: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted | ​ | Weighted
​ | ​ | ​ | ​ | Average | ​ | Average
​ | ​ | ​ | ​ | Exercise | ​ | Remaining
​ | ​ | ​ | ​ | Price | ​ | Contractual
​ |  | Shares |  | Per Share |  | Term (In Years)
Options outstanding at December 31, 2022 |  | 5,085,662 | ​ | $ | 29.26 | ​ | 7.9
Granted |  | 26,900 | ​ | $ | 43.17 | ​ | ​
Exercised |  | (37,492) | ​ | $ | 15.18 | ​ | ​
Canceled |  | (107,306) | ​ | $ | 20.95 | ​ | ​
Options outstanding at March 31, 2023 |  | 4,967,764 | ​ | $ | 29.62 | ​ | 7.6
Options vested and expected to vest at March 31, 2023 |  | 4,884,568 | ​ | $ | 29.72 | ​ | 7.6
Options exercisable at March 31, 2023 |  | 2,273,841 | ​ | $ | 38.18 | ​ | 6.4
Shares available for grant under the 2021 Plan |  | 1,918,374 | ​ | ​ | ​ | ​ | ​
​ The weighted average grant-date fair value of stock options granted during the three months ended March 31, 2023 was $33.25. ​ The aggregate intrinsic value of stock options vested and expected to vest at March 31, 2023 was $78.1 million. The aggregate intrinsic value of stock options exercisable at March 31, 2023 was $42.0 million. As of March 31, 2023, total compensation cost related to non-vested employee, consultant and non-employee director stock options not yet recognized was approximately $38.3 million, net of estimated forfeitures, which is expected to be recognized as expense over a weighted average period of 2.5 years. ​ Stock-based compensation expense for the three months ended March 31, 2023 and 2022 was recorded as follows: ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three months ended March 31,
​ |  | 2023 |  | 2022
​ | ​ | (In thousands)
Research and development | ​ | $ | 2,162 | ​ | $ | 1,614
General and administrative | ​ |  | 2,178 | ​ |  | 1,539
Total stock-based compensation expense | ​ | $ | 4,340 | ​ | $ | 3,153
​ The fair values of employee, consultant and non-employee director stock options granted during the three months ended March 31, 2023 and 2022 were valued using the Black-Scholes option pricing model with the following assumptions: ​
​ | ​ | ​ | ​ | ​
​ | ​ | Three months ended March 31,
|  | 2023 |  | 2022
Expected stock price volatility |  | 92% | ​ | 91 - 97%
Expected option term |  | 6.0 Years | ​ | 6.0 Years
Risk-free interest rate |  | 3.7 - 4.0% | ​ | 1.7 - 1.9%
Expected dividend yield |  | None | ​ | None
​

X
- Definition The entire disclosure for share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -URI https://asc.fasb.org/topic&trid=2228938 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (l) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2)(i) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + 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_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration