Stock-Based Compensation | STOCK-BASED COMPENSATION 2017 Stock Incentive Plan The Board adopted the 2017 Stock Incentive Plan (the "2017 Plan") in February 2017, and the stockholders approved the 2017 Plan in March 2017. The 2017 Plan was most recently amended in March 2020. As of June 30, 2022, there was an aggregate of 646,958 shares of common stock issuable upon the exercise of outstanding options under the 2017 Plan. Any options or awards outstanding under the 2017 Plan remain outstanding and effective. 2020 Equity Incentive Plan In April 2020, the 2020 Equity Incentive Plan (the "2020 Plan") became effective, and, as a result, no further awards will be made under the 2017 Plan. The 2020 Plan provides for the grant of stock options qualifying as incentive stock options ("ISOs"), to employees and for the grant of nonstatutory stock options ("NSOs"), restricted stock awards, restricted stock unit awards, stock appreciation rights, performance stock awards and other forms of stock compensation to employees, and directors. The 2020 Plan also provides for the grant of performance cash awards to employees, consultants and directors. Any previously granted awards under the 2017 Plan will remain outstanding in accordance with their respective terms. Under the 2020 Plan, there is an annual increase on January 1 of each year from January 1, 2021 continuing through January 1, 2030, by 4.0% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares as may be determined by the Board. On January 1, 2022, the Company increased the number of shares available for future grant under the 2020 Plan by 958,993 shares. As of June 30, 2022, there was an aggregate of 2,870,395 shares of common stock issuable upon the exercise of outstanding options under the 2020 Plan. Additionally, there were an aggregate of 1,047,305 shares reserved for future issuance under the 2020 Plan, including shares forfeited from the 2017 Plan. Stock Options A summary of option activity during the six months ended June 30, 2022 is as follows (in thousands except share and per share data): NUMBER OF OPTIONS WEIGHTED-AVERAGE EXERCISE PRICE Outstanding as of December 31, 2021 2,810,684 $ 24.62 Granted 897,358 45.07 Exercised (99,123) 6.25 Cancelled or Forfeited (84,691) 43.24 Expired (6,875) $ (59.94) Outstanding as of June 30, 2022 3,517,353 $ 29.83 Options exercisable as of December 31, 2021 1,223,019 $ 10.48 Options exercisable as of June 30, 2022 1,486,827 $ 16.77 The weighted-average grant date fair value price per share of options granted during the six months ended June 30, 2022 and 2021 was $32.17 and $47.10, respectively. As of June 30, 2022, there was $52.3 million of unrecognized stock-based compensation expense related to unvested stock options. The unrecognized stock-based compensation expense is estimated to be recognized over a period of 2.72 years. The total fair value of options vested during the six months ended June 30, 2022 was $9.4 million. The aggregate intrinsic value of the stock options outstanding and stock options exercisable was $30.4 million and $23.0 million for the six months ended June 30, 2022, respectively. Stock-Based Compensation Expense Total stock-based compensation expense recorded for employees, directors and non-employees during the three and six months ended June 30, 2022 and 2021 was as follows (in thousands): THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2022 2021 2022 2021 Research and development $ 2,100 $ 1,116 $ 3,963 $ 2,014 General and administrative 2,694 1,733 5,219 3,329 Total stock-based compensation expense $ 4,794 $ 2,849 $ 9,182 $ 5,343 |