XML 43 R26.htm IDEA: XBRL DOCUMENT
v3.23.3

Stock-Based Compensation (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2023
Share-Based Payment Arrangement [Abstract] |
Summary of Stock Option Activity Under Plan | The following summarizes option activity under the 2018 Plan:
| Outstanding Options
| Number of Options |  | Weighted- Average Exercise Price |  | Weighted- Average Remaining Contract Term |  | Aggregate Intrinsic Value
|  |  |  |  | (in years) |  | (in thousands)
Balance, December 31, 2022 | 17,569,575 |  |  | $ | 12.90 |  |  | 7.73 |  | $ | 6,658 |
Granted | 9,300,276 |  |  | 5.13 |  |  |  |  |
Exercised | (782,538) |  |  | 2.47 |  |  |  |  | 2,283 |
Forfeited | (4,097,851) |  |  | 10.85 |  |  |  |  |
Balance, September 30, 2023 | 21,989,462 |  |  | $ | 10.37 |  |  | 7.61 |  | $ | 673 |
Exercisable, September 30, 2023 | 13,651,398 |  |  | $ | 12.33 |  |  | 6.95 |  | $ | 673 |
Vested and expected to vest, September 30, 2023 | 21,989,462 |  |  | $ | 10.37 |  |  | 7.61 |  | $ | — |
Schedule Stock Option Valuation Assumptions | The fair value of employee, consultant and director stock option awards was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions:
| Nine Months Ended September 30,
| 2023 |  | 2022
Expected term in years | 5.27 - 6.08 |  | 5.25 - 6.08
Expected volatility | 73.18% - 73.85% |  | 70.82% - 73.39%
Expected risk-free interest rate | 3.45% - 4.30% |  | 1.61% - 3.49%
Expected dividend | 0% |  | 0%
Schedule of Restricted Stock Units Activity Under Plan | The following summarizes restricted stock unit activity under the 2018 Plan:
| Outstanding Restricted Stock Units
| Restricted Stock Units |  | Weighted- Average Grant Date Fair Value per Share |  | Weighted Average Remaining Vesting Life |  | Aggregate Intrinsic Value
|  |  |  |  | (in years) |  | (in thousands)
Unvested December 31, 2022 | 5,493,406 |  |  | $ | 16.86 |  |  | 1.54 |  | $ | 34,554 |
Granted | 11,215,162 |  |  | 4.70 |  |  | 2.0 |  |
Vested | (1,545,458) |  |  | 18.49 |  |  |  |  |
Forfeited | (2,993,273) |  |  | 9.35 |  |  |  |  |
Unvested September 30, 2023 | 12,169,837 |  |  | $ | 7.29 |  |  | 2.14 |  | $ | 38,578 |
Vested and expected to vest, September 30, 2023 | 12,169,837 |  |  | $ | 7.29 |  |  | 2.14 |  | $ | 38,578 |
Schedule of Stock-Based Compensation Expense | Total stock-based compensation expense related to stock options, restricted stock units, employee stock purchase plan and vesting of the founders’ common stock was as follows (in thousands):
| Three Months Ended September 30, |  | Nine Months Ended September 30,
| 2023 |  | 2022 |  | 2023 |  | 2022
Research and development | $ | 6,733 |  |  | $ | 11,016 |  |  | $ | 22,849 |  |  | $ | 35,068 |
General and administrative | 8,621 |  |  | 10,132 |  |  | 27,869 |  |  | 31,286 |
Total stock-based compensation | $ | 15,354 |  |  | $ | 21,148 |  |  | $ | 50,718 |  |  | $ | 66,354 |

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 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 -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_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the changes in outstanding nonvested restricted stock units. + 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)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock
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