XML 101 R28.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Equity Incentive Plans (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2023
Share-Based Payment Arrangement [Abstract] |
Schedule of Activity Related to Stock Option Awards | A summary of the activity related to stock option awards during the year ended December 31, 2023 is as follows:
| Shares Subject to Options |  | Weighted-Average Exercise Price per Share |  | Weighted-Average Remaining Contractual Term (in years) |  | Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2023 | 3,673,208 |  |  | $ | 32.04 |  |  | 6.28 |  | $ | 18,686 |
Granted | 1,579,331 |  |  | $ | 22.02 |  |  |  |  |
Exercises | (90,883) |  |  | $ | 18.95 |  |  |  |  |
Forfeitures and cancellations | (936,041) |  |  | $ | 37.52 |  |  |  |  |
Outstanding at December 31, 2023 | 4,225,615 |  |  | $ | 27.36 |  |  | 7.42 |  | $ | 5,827 |
Exercisable at December 31, 2023 | 2,154,408 |  |  | $ | 30.60 |  |  | 6.10 |  | $ | 4,741 |
Schedule of Time-based Restricted Stock Units Activity |
| Number of Restricted Stock Units |  | Weighted-Average Grant Date Fair Value |  | Weighted-Average Remaining Contractual Term (in years) |  | Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2023 | 1,028,843 |  |  | $ | 26.14 |  |  | 1.17 |  | $ | 31,884 |
Granted | 568,574 |  |  | $ | 22.02 |  |  |  |  |
Released | (68,900) |  |  | $ | 23.89 |  |  |  |  |
Forfeitures and cancellations | (46,945) |  |  | $ | 21.87 |  |  |  |  |
Outstanding at December 31, 2023 | 1,481,572 |  |  | $ | 24.80 |  |  | 0.73 |  | $ | 31,735 |
RSU expected to vest at December 31, 2023 | 1,481,572 |  |  | $ | 24.80 |  |  | 0.73 |  | $ | 31,735 |
Schedule of Weighted Average Assumptions in Stock Option Valuations | The estimated fair values of stock option awards granted were determined on the date of grant using the Black-Scholes option valuation model with the following weighted-average assumptions:
|  | Year Ended December 31,
|  | 2023 |  | 2022 |  | 2021
Risk-free interest rate |  | 3.8 | % |  | 2.5 | % |  | 0.7 | %
Expected volatility |  | 85.7 | % |  | 87.4 | % |  | 92.9 | %
Expected dividend yield |  | — | % |  | — | % |  | — | %
Expected term (in years) |  | 5.82 |  | 6.09 |  | 6.18
Weighted average grant date fair value per share | $ | 16.06 | $ | 21.58 | $ | 22.34
Schedule of Non-cash Stock-based Compensation Expense | Total non-cash stock-based compensation expense for all stock awards that was recognized in the consolidated statements of operations and comprehensive loss is as follows:
|  |  | Year Ended December 31,
(in thousands) |  |  |  |  | 2023 |  | 2022 |  | 2021
Research and development |  |  |  |  | $ | 10,159 |  |  | $ | 6,775 |  |  | $ | 5,856 |
General and administrative |  |  |  |  | 23,046 |  |  | 20,581 |  |  | 9,491 |
Total |  |  |  |  | $ | 33,205 |  |  | $ | 27,356 |  |  | $ | 15,347 |

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

X
- Definition Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- 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 -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- 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 -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (e) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- 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 -Topic 718 -SubTopic 10 -Subparagraph (f)(2) -Name Accounting Standards Codification -Paragraph 2 -Section 50 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration