XML 30 R17.htm IDEA: XBRL DOCUMENT
v3.23.3

Share-Based Compensation | 9 Months Ended
--- | ---
Sep. 30, 2023
Share-Based Compensation |
Share-Based Compensation | 11. Share-Based Compensation Equity Incentive Plan The Company has three equity incentive plans: the 2018 Equity Incentive Plan, as amended, or the 2018 Plan, the 2020 Equity Incentive Plan, or the Incentive Plan, and the 2021 Equity Inducement Plan, as amended, or the Inducement Plan. New awards can only be granted under the Incentive Plan and the Inducement Plan. The total number of shares authorized under the Incentive Plan as of September 30, 2023 was 13,101,661. Additionally, any awards previously issued under the 2018 Plan which are forfeited become available for issuance under the Incentive Plan. As of September 30, 2023, 7,644,421 shares were available for future grants under the Incentive Plan. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the Incentive Plan shall automatically increase on January 1st of each year, commencing on January 1, 2021 and continuing for ten years, in an amount equal to five percent of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the board of directors or compensation committee to determine a lesser number of shares shall be added for such year. As a result, the number of shares reserved for issuance under the Incentive Plan increased by 2,730,735 and 2,712,249 shares in January 2023 and 2022, respectively. The Incentive Plan provides for the granting of common stock, incentive stock options, nonqualified stock options, restricted stock awards, and/or stock appreciation rights to employees, directors, and other persons, as determined by the Company’s board of directors. The Company’s stock options awarded to date under the Incentive Plan vest based on a requisite service period, generally over four-year periods, and have a term of ten years. The Inducement Plan was approved by the Company’s board of directors in July 2021 and subsequently amended in February 2022 and February 2023. The total number of shares authorized under the Inducement Plan as of September 30, 2023 was 2,500,000. Of this amount, 1,006,655 shares were available for future grants as of September 30, 2023. The Inducement Plan provides for the granting of nonqualified stock options and restricted stock awards to employees hired by the Company, as determined by the Company’s board of directors. The Company’s stock options awarded to date under the Inducement Plan vest based on requisite service period and have a term of ten years. The Company’s restricted stock units awarded to date under the Inducement Plan vest based on requisite service period and have a term based on each award agreement. The Company measures share-based awards at their grant date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. The Company recorded share-based compensation expense in the following expense categories in its accompanying statements of operations for the period presented: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three Months Ended September 30, | ​ | Nine Months Ended September 30,
(in thousands) |  | 2023 |  | 2022 | ​ | 2023 |  | 2022
Research and development | ​ | $ | 1,429 | ​ | $ | 568 | ​ | $ | 4,788 | ​ | $ | 6,528
General and administrative | ​ |  | 1,395 | ​ |  | 2,294 | ​ |  | 4,563 | ​ |  | 8,949
​ | ​ | $ | 2,824 | ​ | $ | 2,862 | ​ | $ | 9,351 | ​ | $ | 15,477
​ The following table summarizes stock option activity for the nine months ended September 30, 2023: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | ​ |  | ​ | ​ |  | Weighted | ​
​ | ​ | ​ | ​ | Weighted | ​ | average | ​
​ | ​ | ​ | ​ | average | ​ | remaining | ​
​ | ​ | Number of | ​ | exercise price | ​ | contractual | ​
​ | ​ | shares | ​ | per share | ​ | term (years) | ​
Outstanding at January 1, 2023 |  | 11,411,390 |  | $ | 9.01 |  | 7.1 | ​
Granted |  | 3,348,982 | ​ | ​ | 1.06 |  |  | ​
Exercised |  | — | ​ | ​ | — |  |  | ​
Forfeited |  | (2,256,315) | ​ | ​ | 8.58 |  |  | ​
Expired |  | (2,264,006) | ​ | ​ | 12.50 |  |  | ​
Outstanding at September 30, 2023 |  | 10,240,051 | ​ | $ | 5.73 |  | 8.2 | ​
Vested and exercisable at September 30, 2023 |  | 4,935,214 | ​ | $ | 8.43 |  | 7.4 | ​
Vested or expected to vest at September 30, 2023 |  | 10,240,051 | ​ | $ | 5.73 |  | 8.2 | ​
​ The weighted average grant date fair value of options granted was $0.82 and $2.52 for the nine months ended September 30, 2023 and 2022, respectively. As of September 30, 2023, the total unrecognized compensation expense related to unvested stock option awards was $12.4 million, which the Company expects to recognize over a weighted average period of 1.9 years. The 2018 Plan and the Incentive Plan provide certain holders of stock options an election to early exercise prior to vesting. The Company has the right to repurchase early exercised options without transferring any appreciation in the value of the underlying shares to the employee if the employee terminates employment before the end of the original vesting period. The repurchase price is the lesser of the original exercise price or the then fair value of the Company’s common stock. As of September 30, 2023, 3,426 options to purchase common stock are unvested, but exercisable, under early exercise provisions. The fair value of each option was estimated on the date of grant using the weighted average assumptions in the table below: ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Nine Months Ended September 30,
​ | ​ | 2023 | ​ | 2022
Expected volatility | ​ | 92.6 | % | ​ | 92.3 | %
Risk‑free interest rate | ​ | 3.6 | % | ​ | 2.6 | %
Expected term | ​ | 6.0 | years | ​ | 5.8 | years
Expected dividend yield | ​ | — | ​ | ​ | — | ​
​ Restricted Stock Units The Company issues restricted stock units, or RSUs, to employees that vest over periods as determined by the board of directors. Any unvested shares are forfeited upon termination of services. The fair value of the RSUs is equal to the fair market value price of the Company’s common stock on the date of grant. Compensation expense is recognized on a straight-line basis over the vesting period of the RSUs. ​ The following table summarizes activity related to RSU awards during the nine months ended September 30, 2023: ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ |  | ​ |  | ​ | Weighted average
​ | ​ |  | Number of shares |  | ​ | grant date fair value
Unvested balance at January 1, 2022 | ​ |  | 1,229,166 |  | $ | 2.98
Granted | ​ |  | 195,000 |  | $ | 1.01
Vested | ​ | ​ | (98,042) | ​ | ​ | 5.82
Forfeited | ​ |  | (179,625) |  | $ | 2.13
Unvested balance at September 30, 2023 | ​ |  | 1,146,499 |  | $ | 2.58
​ As of September 30, 2023, the total unrecognized expense related to all RSUs was $1.5 million, which the Company expects to recognize over a weighted average period of 1.1 years. ​ Employee Stock Purchase Plan The Company’s 2020 Employee Stock Purchase Plan, or the ESPP, became effective on February 28, 2020. The ESPP authorizes the issuance of up to 1,981,766 shares of the Company’s common stock. Of this amount, 1,565,821 were available for future grants as of September 30, 2023. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the ESPP shall automatically increase on January 1st of each year and continuing for ten years, in an amount equal to one percent of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the board of directors or compensation committee to determine a lesser number of shares shall be added for such year. As a result, on January 1, 2023, the number of shares reserved for issuance under the ESPP increased by 546,147 shares, resulting in a total of 1,981,766 shares authorized for issuance. Under the ESPP, eligible employees can purchase the Company’s common stock through accumulated payroll deductions at such times as are established by the compensation committee. Eligible employees may purchase the Company’s common stock at 85% of the lower of the fair market value of the Company’s common stock on the first day of the offering period or on the last day of the offering period. The offering periods under the ESPP have a duration of six months, with periods ending in May and November of each calendar year. Eligible employees may contribute up to 15% of their eligible compensation. Under the ESPP, a participant may not accrue rights to purchase more than $25,000 worth of the Company’s common stock for each calendar year in which such right is outstanding or purchase more than 4,000 shares of the Company’s common stock in any single offering period. In accordance with the guidance in ASC 718-50, Compensation – Stock Compensation, the ability to purchase shares of the Company’s common stock at 85% of the lower of the price on the first day of the offering period or the last day of the offering period (i.e. the purchase date) represents an option and, therefore, the ESPP is a compensatory plan under this guidance. Accordingly, share-based compensation expense is determined based on the option’s grant-date fair value as estimated by applying the Black-Scholes option-pricing model and is recognized over the withholding period. The Company did not recognize any share-based compensation expense during both the three months ended September 30, 2023 and 2022. The Company recognized expense related to the ESPP of $0 and $0.2 million during the nine months ended September 30, 2023 and 2022, respectively.

X
- Definition The entire disclosure for share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -URI https://asc.fasb.org/topic&trid=2228938 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (l) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2)(i) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration