Share-based Compensation | 8. Share-based Compensation 2022 Equity Inducement Plan In October 2022, the board of directors and stockholders approved the 2022 Equity Inducement Plan, or the 2022 Plan. The 2022 Plan provides for the grant of non-statutory stock options and restricted stock units. The number of shares of common stock reserved for issuance under the 2022 Plan is 1,000,000 shares. The following table provides a summary of stock option activity under the 2022 Plan during the three months ended March 31, 2023. Options Weighted-Average Weighted-Average Aggregate Outstanding at December 31, 2022 309,000 $ 21.14 Granted — $ — Exercised — $ — $ — Forfeiture — $ — Outstanding at March 31, 2023 309,000 $ 21.14 9.6 $ — Vested and expected to vest at March 31, 2023 309,000 $ 21.14 9.6 $ — Exercisable at March 31, 2023 — $ — — $ — Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money options. There was no fair value of options that vested during each of the three months ended March 31, 2023 and 2022. There was no weighted-average grant date fair value of options granted since there were no options granted from the 2022 Plan during each of the three months ended March 31, 2023 and 2022. Unamortized share-based compensation for stock options as of March 31, 2023 was $ 4.2 million, which is expected to be recognized over a weighted-average period of 3.6 years. The following table provides a summary of restricted stock units activity under the 2022 Plan during the three months ended March 31, 2023: Number of Weighted Average Unvested restricted stock units at December 31, 2022 47,400 $ 21.14 Granted — $ — Vested — $ — Forfeiture — $ — Unvested restricted stock units at March 31, 2023 47,400 $ 21.14 Unamortized share-based compensation for restricted stock units as of March 31, 2023 was $ 0.9 million, which is expected to be recognized over a weighted-average period of 3.6 years. 2021 Equity Incentive Plan Immediately prior to consummation of the Company’s initial public offering, or the IPO, all the outstanding incentive shares were converted into common stock. The following table provides a summary of the unvested common stock awards activity during the three months ended March 31, 2023. Number of Weighted Average Unvested common stock as of December 31, 2022 1,722,744 $ 16.00 Vested ( 251,620 ) $ 16.00 Forfeiture ( 21,400 ) $ 16.00 Unvested common stock as of March 31, 2023 1,449,724 $ 16.00 In May 2021, in connection with the IPO, the board of directors and stockholders approved, the 2021 Equity Incentive Plan, or the 2021 Plan, which became effective on the day before the date of the effectiveness of the IPO. The 2021 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, awards of restricted stock, restricted stock units and other share-based awards. The number of shares of common stock reserved for issuance under the 2021 Plan is equal to the sum of: (x) 6,369,000 shares of common stock; plus (y) 4,719,605 shares of common stock issued in respect of the Conversion of incentive shares that were subject to vesting immediately prior to the effectiveness of the registration statement for the IPO that expire, terminate or are otherwise surrendered, canceled, forfeited or repurchased by us at their original issuance price pursuant to a contractual repurchase right. The number of shares available for grant and issuance under the 2021 Plan will be automatically increased on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2021 and continuing for each fiscal year until, and including, the fiscal year commencing on January 1, 2031, by the lesser of (a) 5 % of the number of shares of all classes of the Company’s common stock, plus the total number of shares of Company common stock issuable upon conversion of any preferred stock or exercise of any warrants to acquire shares of Company common stock for a nominal exercise price issued and outstanding on each December 31 immediately prior to the date of increase or (b) such number of shares determined by the board of directors. The following table provides a summary of stock option activity under the 2021 Plan during the three months ended March 31, 2023. Options Weighted-Average Weighted-Average Aggregate Outstanding at December 31, 2022 7,634,167 $ 16.42 Granted 1,515,000 $ 23.25 Exercised ( 75,184 ) $ 15.74 $ 612 Forfeiture ( 90,552 ) $ 20.04 Outstanding at March 31, 2023 8,983,431 $ 17.54 8.7 $ 1,099 Vested and expected to vest at March 31, 2023 8,983,431 $ 17.54 8.7 $ 1,099 Exercisable at March 31, 2023 2,828,518 $ 16.55 8.4 $ 61 Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money options. The total fair value of options that vested during the three months ended March 31, 2023 and 2022 was $ 6.3 million and $ 1.7 million, respectively. The weighted-average grant date fair value of options granted during the three months ended March 31, 2023 and 2022 was $ 16.63 per share and $ 8.47 per share, respectively. Unamortized share-based compensation for stock options as of March 31, 2023 was $ 67.5 million, which is expected to be recognized over a weighted-average period of 2.9 years. The Company used the Black-Scholes option pricing model to estimate the fair value of stock options awards granted with the following assumptions: Three Months Ended 2023 2022 Expected term (in years) 5.86 - 6.25 5.90 - 6.08 Expected volatility 80.79 % - 81.98 % 65.20 % - 66.92 % Risk-free interest rate 3.55 % - 4.08 % 1.47 % - 2.55 % Expected dividend yield — — The following table provides a summary of restricted stock units activity under the 2021 Plan during the three months ended March 31, 2023: Number of Weighted Average Unvested restricted stock units at December 31, 2022 485,351 $ 16.83 Granted 510,660 $ 23.23 Vested ( 60,673 ) $ 20.08 Forfeiture ( 18,038 ) $ 21.04 Unvested restricted stock units at March 31, 2023 917,300 $ 20.10 Unamortized share-based compensation for restricted stock units as of March 31, 2023 was $ 17.4 million, which is expected to be recognized over a weighted-average period of 3.4 years. Performance Awards In June 2022, the Company granted performance awards, consisting of performance stock options, or PSOs, and performance stock units, or PSUs, to non-executive employees pursuant to the 2021 Equity Incentive Plan. Each performance award is earned through the achievement of a performance-based metric over a defined performance period determined by the compensation committee of the Company's board of directors. The estimated fair value of the equity awards that contain performance conditions is expensed over the term of the award once the Company has determined that it is probable that the performance conditions will be satisfied. As of March 31, 2023, the Company has granted 152,550 PSOs with a weighted-average grant date fair value of $ 7.78 per share and 99,250 PSUs with a weighted-average grant date fair value of $ 15.25 per share. The total fair values of PSOs and PSUs granted were $ 1.2 million and $ 1.5 million, respectively. As of March 31, 2023, no PSOs or PSUs had vested since the achievement of the performance-based metrics of the performance awards was not deemed probable. For the three months ended March 31, 2023 and 2022, the Company has not granted any performance awards under the 2021 Plan. 2021 Employee Stock Purchase Plan In May 2021, the board of directors adopted, and the stockholders approved the 2021 Employee Stock Purchase Plan, or the ESPP, which became effective on May 26, 2021. A total of 603,000 shares of common stock were initially reserved for issuance under the ESPP. The number of shares of the common stock reserved for issuance under the ESPP will automatically increase on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2021 and continuing for each fiscal year until, and including, the fiscal year commencing on January 1, 2031, by the lesser of: (a) 1 % of the total number of outstanding shares of common stock of the Company (on an as converted basis outstanding on the immediately preceding December 31 (rounded down to the nearest whole share) and (b) an amount determined by the board of directors. 97,413 shares have been issued under the ESPP as of March 31, 2023. The Company recognized $ 0.2 million and $ 0.1 million compensation expense related to the ESPP for the three months ended March 31, 2023 and 2022, respectively. For the three months ended March 31, 2023 and 2022, the Company has not issued any shares pursuant to the ESPP. Share-based compensation expense recorded in the accompanying condensed consolidated statements of operations is as follows (in thousands): Three Months Ended 2023 2022 Research and development expense $ 3,380 $ 2,147 General and administrative expense 6,067 4,055 Total share-based compensation expense $ 9,447 $ 6,202 As of March 31, 2023, there was $ 96.6 million of unrecognized compensation cost related to unvested restricted stock, unvested restricted stock units, unvested stock options, and shares subject to purchase under the ESPP that is expected to be recognized over a weighted-average period of approximately 3.0 years. As of March 31, 2023, there was $ 2.6 million of unrecognized compensation cost related to unvested PSOs and PSUs. The Company will recognize the PSO and PSU expense through the expected vesting dates when the achievement of the performance-based metrics is probable. |