XML 45 R35.htm IDEA: XBRL DOCUMENT
v3.21.2

Stock-Based Compensation (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] |
Summary of Stock Option Activity | A summary of stock option activity for the six months ended June 30, 2021 is set forth below:
|  | Number of Shares Available for Grant |  |  | Number of Shares Underlying Outstanding Options |  |  | Weighted- Average Exercise Price |  |  | Weighted- Average Remaining Contractual Term (in years) |  |  | Aggregate Intrinsic Value (in thousands) |
Outstanding, December 31, 2020 |  |  | 1,739,621 |  |  |  | 3,706,945 |  |  | $ | 10.90 |  |  |  | 7.98 |  |  | $ | 15,126 |
Options authorized |  |  | 2,287,089 |  |  |  | — |  |  |  |  |  |  |  |  |  |
Options granted |  |  | (1,911,472 | ) |  |  | 1,911,472 |  |  | $ | 15.04 |  |  |  |  |  |  |
Options exercised |  |  | — |  |  |  | (433,594 | ) |  | $ | 2.91 |  |  |  |  |  |  |
Options forfeited or cancelled |  |  | 745,006 |  |  |  | (745,006 | ) |  | $ | 14.26 |  |  |  |  |  |  |
Outstanding, June 30, 2021 |  |  | 2,860,244 |  |  |  | 4,439,817 |  |  | $ | 12.90 |  |  |  | 8.20 |  |  | $ | 4,948 |
Shares exercisable, June 30, 2021 |  |  |  |  |  | 1,288,596 |  |  | $ | 8.43 |  |  |  | 5.20 |  |  | $ | 4,522 |
Vested and expected to vest, June 30, 2021 |  |  |  |  |  | 4,439,817 |  |  | $ | 12.90 |  |  |  | 8.20 |  |  | $ | 4,948 |
Summary of Stock-Based Compensation Expense | Total stock-based compensation expense recognized was as follows (in thousands):
|  | Three Months Ended June 30, |  |  | Six Months Ended June 30, |
|  | 2021 |  |  | 2020 |  |  | 2021 |  |  | 2020 |
Research and development |  | $ | 825 |  |  | $ | 88 |  |  | $ | 2,413 |  |  | $ | 174 |
General and administrative |  |  | 1,834 |  |  |  | 263 |  |  |  | 3,289 |  |  |  | 476 |
Total stock-based compensation |  | $ | 2,659 |  |  | $ | 351 |  |  | $ | 5,702 |  |  | $ | 650 |
Schedule of Assumptions to Estimate Fair Value of Stock Options Using Black-Scholes Option Pricing Model | The assumptions used in the Black Scholes Model to calculate stock-based compensations are as follows:
|  | Three Months Ended June 30, |  | Six Months Ended June 30,
|  | 2021 |  | 2020 |  | 2021 |  | 2020
Fair value of common stock |  | $10.29 - $15.93 |  | N/A |  | $10.29 - $16.82 |  | $1.48
Expected term (years) |  | 0.9 - 6.1 |  | N/A |  | 0.9 - 6.1 |  | 6.1 - 6.8
Volatility |  | 77.9% - 78.6% |  | N/A |  | 77.9% - 79.8% |  | 80.3% - 82.6%
Risk free rates |  | 0.1% - 1.1% |  | N/A |  | 0.1% - 1.1% |  | 0.4% - 0.5%
Dividend rate |  | 0.0% |  | N/A |  | 0.0% |  | 0.0%

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 -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum: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 -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=120381028&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 http://asc.fasb.org/extlink&oid=120381028&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 http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum: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 -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration