v3.22.4

Stockholders’ Equity and Stock-Based Compensation (Tables) | 12 Months Ended
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Dec. 31, 2022
Equity [Abstract] |
Schedule of Warrant Activity | A summary of the Company’s warrant activity for the year ended December 31, 2022 was as follows:
| Shares of Stock under Warrants |  | Weighted- Average Exercise Price |  | Weighted- Average Remaining Contractual Term |  | Aggregate Intrinsic Value
Outstanding at January 1, 2021 | 15,174,000 |  |  | $ | 2.34 |  |  | 3.76 |  | $ | 26,841,000 |
Granted | — |  |  | — |  |  |  |  | — |
Exercised | (10,794,000) |  |  | 0.88 |  |  |  |  | 58,191,000 |
Canceled | (24,000) |  |  | 3.29 |  |  |  |  | — |
Outstanding at December 31, 2021 | 4,356,000 |  |  | $ | 5.96 |  |  | 1.76 |  | $ | 785,000 |
Granted | — |  |  | — |  |  |  |  | — |
Exercised | — |  |  | — |  |  |  |  | — |
Canceled | — |  |  | — |  |  |  |  | — |
Outstanding at December 31, 2022 | 4,356,000 |  |  | $ | 5.96 |  |  | 0.76 |  | $ | 273,000 |
Summary of Stock Option Activity Under 2018 Plan and 2006 Plan | A summary of the Company’s stock option activity is as follows:
| Shares of Stock under Stock Options |  | Weighted- Average Exercise Price |  | Weighted- Average Remaining Contractual Term |  | Aggregate Intrinsic Value
Outstanding at January 1, 2022 | 12,765,000 |  | $ | 4.97 |  |  | 8.9 |  | $ | 7,891,000 |
Granted | 16,148,000 |  | 2.12 |  |  |  |  |
Exercised | (467,000) |  | 0.74 |  |  |  |  | 580,000 |
Canceled | (4,424,000) |  | 4.18 |  |  |  |  |
Outstanding at December 31, 2022 | 24,022,000 |  | 3.28 |  | 8.5 |  | 2,068,000 |
Vested and exercisable at December 31, 2022 | 7,791,000 |  | $ | 3.79 |  |  | 7.5 |  | $ | 1,513,000 |
Share-based Payment Arrangement, Restricted Stock Unit, Activity | Restricted stock activity was as follows:
| Stock Units |  | Weighted- Average Grant Date Fair Value per Share
Outstanding at January 1, 2022 | 361,000 |  | $ | 4.74 |
Granted | — |  | —
Released | (265,000) |  | 4.74
Forfeited | — |  | — |
Outstanding at December 31, 2022 | 96,000 |  | $ | 4.74
Performance stock activity was as follows:
| Stock Units |  | Weighted- Average Grant Date Fair Value per Share
Outstanding at January 1, 2022 | 290,000 |  | $ | 4.74 |
Granted | — |  | —
Released | — |  | —
Forfeited | — |  | —
Outstanding at December 31, 2022 | 290,000 |  | $ | 4.74
Summary of Recognized Stock-Based Compensation Expense | The Company recognized stock-based compensation expense for the years ended December 31, 2022 and 2021 was as follows:
| Years Ended December 31,
| 2022 |  | 2021
Research and development | $ | 13,402,000 |  |  | $ | 3,531,000 |
General and administrative | 9,015,000 |  |  | 6,188,000 |
Total stock-based compensation expense | $ | 22,417,000 |  |  | $ | 9,719,000 |
Schedule of Weighted-Average Assumptions in Black -Scholes Option Pricing Model | The weighted-average assumptions used in the Black-Scholes-Merton option pricing model to determine the fair value of the employee stock option grants were as follows:
| Years Ended December 31,
| 2022 |  | 2021
Risk-free interest rate | 2.4% |  | 1.1%
Expected volatility | 68.0% |  | 76.2%
Expected term (in years) | 5.8 |  | 6.0
Expected dividend yield | 0.0% |  | 0.0%

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- Definition Tabular disclosure of allocation of amount expensed and capitalized for award under share-based payment arrangement to statement of income or comprehensive income and statement of financial position. Includes, but is not limited to, corresponding line item in financial statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 50 -Section S99 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6784392&loc=d3e188667-122775 + Details
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