STOCK BASED COMPENSATION | 7 . STOCK‑BASED COMPENSATION Equity Incentive Plans In May 2019, the Company's board of directors (the "Board") adopted its 2019 Equity Incentive Plan ("2019 Plan"), which was subsequently approved by its stockholders and became effective on May 13, 2019. As a result, no additional awards under the Company's 2016 Equity Incentive Plan, as amended (the "2016 Plan") will be granted and all outstanding stock awards granted under the 2016 Plan that are repurchased, forfeited, expired or are cancelled will become available for grant under the 2019 Plan in accordance with its terms. The 2016 Plan will continue to govern outstanding equity awards granted thereunder. The 2019 Plan provides for the issuance of incentive stock options ("ISOs") to employees, and for the grant of nonstatutory stock options ("NSOs"), stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards and other forms of stock awards to the Company's employees, officers and directors, as well as non- employees, consultants and affiliates to the Company. Under the terms of the 2019 Plan, stock options may not be granted at an exercise price less than fair market value of the Company's common stock on the date of the grant. The 2019 Plan will be administered by the Compensation Committee of the Company's Board. Initially, subject to adjustments as provided in the 2019 Plan, the maximum number of the Company's common stock that may be issued under the 2019 Plan is 4,530,000 shares, which is the sum of (i) 1,618,841 new shares, plus (ii) the number of shares (not to exceed 2,911,159 shares) that remained available for the issuance of awards under the 2016 Plan, at the time the 2019 Plan became effective, and (iii) any shares subject to outstanding stock options or other stock awards granted under the 2016 Plan that are forfeited, expired, or reacquired. The 2019 Plan provides that the number of shares reserved and available for issuance under the 2019 Plan will automatically increase each January 1, beginning on January 1, 2020, by 5% of the outstanding number of shares of common stock on the immediately preceding December 31 or such lesser number of shares as determined by the Board. Subject to certain changes in capitalization of the Company, the aggregate maximum number of shares of common stock that may be issued pursuant to the exercise of ISOs shall be equal to 13,000,000 shares of common stock. Stock options awarded under the 2019 Plan expire 10 years after grant and typically vest over four years. As of March 31, 2020, there were 2,675,770 shares reserved by the Company to grant under the 2016 and 2019 Plans and an aggregate of 1,100,671 shares remained available for future grants under the 2019 Plan. Stock-Based Compensation Expense Total stock-based compensation expense recorded for employees, directors and non-employees during the three months ended March 31, 2020 and 2019 was as follows: Three Months Ended March 31, (in thousands) 2020 2019 Research and development $ 642 $ $ 147 General and administrative 670 178 Total stock-based compensation expense $ 1,312 $ 325 During the three months ended March 31, 2020, the Company granted options to purchase 194,031 shares of common stock. The Company recorded stock-based compensation expense for options granted during the three months ended March 31, 2020 and 2019 of $1.3 million and $0.3 million, respectively. As of March 31, 2020 and December 31, 2019, there were 4,238,892 and 4,079,888 options outstanding, respectively. The weighted‑average fair value of options granted during the three months ended March 31, 2020 and 2019 was $21.65 and $1.54 per share, respectively. As of March 31, 2020, and March 31, 2019, the total unrecognized stock‑based compensation balance for unvested options was $15.4 million and $5.3 million, respectively, which is expected to be recognized over a period of 1.6 years and 2.3 years, respectively. The following table summarizes the information about options outstanding at March 31, 2020: Weighted-Average Weighted- Remaining Aggregate Options Average Contractual Intrinsic (in thousands, except for share data) Outstanding Exercise Price Term (in years) Value Outstanding at December 31, 2019 4,079,888 $ 5.11 8.26 $ 82,327 Options granted 194,031 35.43 Options exercised (35,027) 2.32 — Forfeited — — Expired — — Outstanding at March 31, 2020 4,238,892 $ 8.16 8.83 $ 104,515 Exercisable at March 31, 2020 2,073,735 $ 3.22 8.42 $ 61,123 Nonvested at March 31, 2020 2,165,157 $ 12.89 9.23 $ 43,392 Valuation of Stock Options Granted to Employees that Contain Service Conditions Only The fair value of each option award granted with service-based vesting is estimated on the date of the grant using the Black-Scholes option valuation model based on the weighted average assumptions noted in the table below for those options granted in the years ended March 31, 2020 and 2019. Three Months Ended March 31, 2020 2019 Expected term (in years) 6.1 6.0 Volatility % 68.44 % Risk-free interest rate 0.59 % 2.47 % Dividend yield 0.00 % 0.00 % Stock Options Granted to Employees that Contain Service, Performance and Market Conditions Included in the stock options granted during the three months ended March 31, 2019 were 159,501 stock options that contain service-, performance- and market-based vesting conditions granted to the Company's interim Chief Financial Officer ("CFO") with a fair value at the grant date of $0.5 million, valued using the Monte-Carlo simulation model. The derived service period, calculated using the Monte-Carlo simulation model, ranged from one day to three years. The assumptions used in the Monte-Carlo simulation model were as follows: Three Months Ended March 31, 2020 Time to expiration (in years) 10.0 Volatility 68.54 % Risk-free interest rate 2.64 % Dividend yield 0.00 % Cost of equity 24.00 % Fair value of underlying common stock (as of valuation date) $ 5.85 The compensation expense for these awards is recognized over the derived service period, or, if earlier, until the vesting condition is met. The condition for the performance-based stock options was based on the Company's completion of its IPO and the condition for the market-based stock options was based on the future price of the Company's common stock trading at or above a specified threshold. As of March 31, 2020 there were no outstanding stock options containing service-, performance-, and market-based vesting conditions. The Company recorded $0.1 million in compensation expense related to these awards for the three months ended March 31, 2019. Issuance of Restricted Common Stock On March 9, 2020, the Board of Directors of the Company approved the grant of 36,464 restricted stock units (the “RSUs”) to an employee of the Company, pursuant to the 2019 Equity Plan. One-fourth of the RSUs shall vest in four equal annual installments commencing one year after the date of grant, subject to the employee continuing to provide services through each such date. These shares were valued at $1.3 million, determined using price per share of $34.28, the closing price of the Company’s common stock on March 9, 2020, and will be amortized ratably over the term of the vesting periods of three years on a straight line basis. For the three months ended March 31, 2020, amortization of deferred stock compensation of these shares amounted to $19,000. As of March 31, 2020, the unamortized deferred compensation costs associated with non-vested restricted stock awards were $1.2 million with a weighted-average remaining amortization period of 3.9 years. 2019 Employee Stock Purchase Plan In May 2019, the Company’s Board and its stockholders approved the 2019 Employee Stock Purchase Plan (the “2019 ESPP”), which became effective as of May 13, 2019. The ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the U.S. Internal Revenue Code of 1986, as amended. The number of shares of common stock initially reserved for issuance under the ESPP was 180,000 shares. The ESPP provides for an annual increase on the first day of each year beginning in 2020 and ending in 2029, in each case subject to the approval of the Board, equal to the lesser of (i) 1% of the shares of common stock outstanding on the last day of the calendar month before the date of the automatic increase and (ii) 360,000 shares; provided that prior to the date of any such increase, the Board may determine that such increase will be less than the amount set forth in clauses (i) and (ii). As of March 31, 2020, no shares of common stock had been issued under the ESPP. The first offering period has not yet been decided by the Board. |