XML 134 R19.htm IDEA: XBRL DOCUMENT v3.23.1
Stock-Based Compensation
 12 Months Ended
Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]  
Stock-Based Compensation STOCK-BASED COMPENSATION
Summary of Plans— The Company issues stock awards under the following plans: (a) The 2015 Employee, Director and Consultant Equity Incentive Plan, as amended (the “2015 Plan”), (b) the Amended and Restated 2017 Equity Incentive Plan (the “2017 Plan”), (c) the 2017 Employee Stock Purchase Plan (the “2017 ESPP”) and the 2019 Inducement Equity Incentive Plan (the “2019 Plan”).
These plans are administered by the Board of Directors or by a committee thereof. The exercise prices, vesting and other restrictions are determined at the discretion of the Board of Directors, or its committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant and the term of the stock option may not be greater than ten years. Incentive stock options granted to employees and restricted stock awards granted to employees, officers, members of the Board of Directors, advisors, and consultants of the Company typically vest over four years. Non-statutory options granted to employees, officers, members of the Board of Directors, advisors, and consultants of the Company typically vest over three or four years. Shares that are expired, terminated, surrendered or canceled under the Plans without having been fully exercised will be available for future awards. In addition, shares of common stock that are tendered to the Company by a participant to exercise an award are added to the number of shares of common stock available for the grant of awards.
2015 Employee, Director and Consultant Equity Incentive Plan—Under the 2015 Plan, the Company grants incentive stock options, nonqualified stock options, restricted stock awards and other stock-based awards to employees, directors and consultants of the Company. As of December 31, 2022, there were approximately 19 thousand shares available for issuance under the 2015 Plan.
2017 Equity Incentive Plan— Under the 2017 Plan, the Company may grant incentive stock options, non-qualified options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. Under an “evergreen” provision of the 2017 Plan, shares of common stock reserved for issuance under the 2017 Plan are increased annually on the first day of each year, beginning on January 1, 2021 and ending on January 1, 2027, in an amount equal to the lower of 4.0% of the number of shares of the Company’s common stock outstanding on January 1 of each year or an amount determined by the Company’s Board of Directors. As of December 31, 2022, approximately 298 thousand shares were available for future issuance under the 2017 Plan. As of January 1, 2023, an additional 4.8 million shares became available for future issuance under the 2017 Plan under the evergreen provision.
2017 Employee Stock Purchase Plan— The 2017 ESPP provides participating employees with the opportunity to purchase shares of the Company’s common stock at defined purchase prices over six-month offering periods. For the twelve months ended December 31, 2022, 204,903 shares of common stock were issued under the 2017 ESPP. As of December 31, 2022, approximately 64 thousand shares were available for future issuance under the 2017 ESPP. Pursuant to the evergreen provision of the 2017 ESPP, on January 1, 2023, an additional 85 thousand shares became available for future issuance under the 2017 ESPP.
2019 Inducement Equity Incentive Plan— On June 17, 2019, the Board of Directors approved the adoption of the 2019 Plan, as amended, which is used exclusively for the grant of equity awards to individuals who were not previously employees of the Company (or following a bona fide period of non-employment), as an inducement material to such individual’s entering into employment with the Company, pursuant to Nasdaq Listing Rule 5635(c)(4). The total number of shares of common stock that may be issued under the 2019 Plan, as amended, is 2.3 million shares. Shares that are expired, forfeited, canceled or otherwise terminated without having been fully exercised will be available for future grant under the 2019 Plan. In addition, shares of common stock that are tendered to the Company by a participant to exercise an award are added to the number of shares of common stock available for future grants. As of December 31, 2022, approximately 1.3 million shares were available for future issuance under the 2019 Plan.
Stock Option Valuation— The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted:


Year Ended
December 31,



2022

20212020
Risk-free interest rate


3.4 %

1.0 %0.6 %
Expected term (in years)


6.06

5.966.01
Expected volatility


96.0 %

97.3 %94.9 %
Expected dividend yield


0 %

0 %0 %
Stock Options
The following table summarizes the Company’s stock option activity for the twelve months ended December 31, 2022:

Number of
Shares

Weighted
Average
Exercise
Price

Weighted
Average
Contractual
Term
(in Years)

Aggregate Intrinsic
Value
(in Thousands)
Outstanding as of December 31, 20211,916,051 

$10.01 

7.8

$— 
Granted759,200 

1.76 




Forfeited(653,771)

9.75 




Outstanding as of December 31, 20222,021,480 

$6.99 

6.5

$1 
Exercisable as of December 31, 20221,114,604 

$9.93 

6.3

$— 
Vested and expected to vest as of December 31, 20221,722,110 

$7.77 

7.3

$— 
The aggregate intrinsic value of options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock to the extent the stock option had a lower exercise price. The aggregate intrinsic value of stock options exercised during the twelve months ended December 31, 2021 and 2020 was $13 thousand and $42 thousand, respectively. There were no stock options exercised for the twelve months ended December 31, 2022. The weighted average grant-date fair value per share of stock options granted during the years ended December 31, 2022, 2021 and 2020 was $1.38, $5.17, and $6.12, respectively.
Restricted Stock Units— During the twelve months ended December 31, 2022, the Company granted 1.8 million restricted stock units to employees at a weighted average grant date fair value of $2.09 per share. These restricted stock units are time-based and vest annually as the employee provides services to the Company. The Company recognizes stock-based compensation expense ratably, net of estimated forfeitures, over the estimated vesting period.
The following table summarizes the Company’s restricted stock activity for the twelve months ended December 31, 2022:
Number of Shares
Unvested at December 31, 2021925,101 
Granted1,814,425 
Vested(384,814)
Forfeited(674,149)
Unvested at December 31, 20221,680,563 
Stock-Based Compensation— As of December 31, 2022, total unrecognized compensation expense related to unvested stock options and restricted stock units was $4.4 million, which is expected to be recognized over a weighted average period of 1.5 years.
Stock-based compensation expense was classified in the consolidated statements of operations as follows:

Year Ended
December 31,

2022

20212020
Research and development expense$2,534 

$2,723 $2,316 
Selling, general and administrative expense2,665 

3,457 3,112 
Total stock-based compensation$5,199 

$6,180 $5,428 
Stock Appreciation Rights— On November 7, 2022 (the “Grant Date”), the compensation committee of the Board of Directors approved special retention and recognition grants of stock appreciation rights pursuant to the 2017 Plan to the Company’s President and Chief Executive Officer, the Company’s Chief Financial Officer and Treasurer, and certain other executive officers of the Company. The SARs have a measurement price per SAR equal to $1.80, the closing price per share of the Company’s common stock on the Grant Date, and each grant of SARs will have a maximum term of ten years from the Grant Date. Unless otherwise determined by the Board of Directors, the SARs will be settled in cash upon exercise. The settlement value will be based on the difference between the closing price of the Company’s common stock on the date of settlement less $1.80 multiplied by the number of SARs exercised. The SARs will vest and become exercisable in equal annual installments on the first, second, and third anniversaries of the Grant Date, subject to the recipient remaining an employee of the Company through and including each applicable vesting date.
The calculation of the fair value of the outstanding SARs includes the closing price of the Company’s common stock of $0.99 and the following assumptions on a weighted average basis:
December 31,
2022
Risk-free interest rate3.95 %
Expected term (in years)5.86
Expected volatility96.96 %
Expected dividend yield— %
Expected Forfeiture Rate22 %
The SARs are accounted for as liability awards as settlement will be in the form of cash unless the Board of Directors authorizes settlement in shares of the Company’s common stock and such shares are available to be issued from the 2017 Plan. The Company currently intends to settle the SARs in cash if and when exercised. Compensation expense is recorded based the fair value of the SARs, as determined using the Black-Scholes option valuation model, using an accelerated attribution method as the SARs vest. The Company remeasures the fair value of the outstanding SARs each period until settlement and adjusts life-to-date compensation expense to the period end SARs fair value. For the year ended December 31, 2022, the Company recognized $373 thousand of compensation expense related to the SARs.