Stock-Based Compensation

3 Months Ended

Mar. 31, 2024

Stock-Based Compensation

Stock-Based Compensation

15. Stock-Based Compensation

2019 Inducement Plan

In October 2019, the Company’s Board of Directors adopted the 2019 Inducement Plan, or the 2019 Plan, which is a non-stockholder approved stock plan adopted pursuant to the “inducement exception” provided under Nasdaq Listing Rule 5635(c)(4), or Rule 5635, for the purpose of awarding (i) non-statutory stock options, (ii) restricted stock awards, (iii) restricted stock unit awards, (iv) other stock awards (collectively, the Inducement Awards) to new employees of the Company, as inducement material to such new employees entering into employment with the Company. In November 2019, the Company filed a Registration Statement on Form S-8 with the SEC covering the offering of up to 300,000 shares of its common stock, par value $0.001, pursuant to the Company’s 2019 Plan. Initial grants of Inducement Awards made to employees vest as to 25% on the first anniversary of the date of grant and the balance ratably over the next 36 months and subsequent grants vest monthly over a period of four years from the grant date.

2014 Equity Incentive Plan

The Company’s 2014 Equity Incentive Plan, or the 2014 Plan, is administered by the Company’s Board of Directors or a duly authorized committee thereof, referred to as the Plan administrator. The 2014 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, performance stock awards and other forms of equity compensation, collectively referred to as Stock Awards. Additionally, the 2014 Plan provides for the grant of performance cash awards. Incentive stock options may be granted only to employees. All other awards may be granted to employees, including officers, non-employee directors, and consultants. No incentive stock options may be granted under the 2014 Plan after the tenth anniversary of the effective date of the 2014 Plan. Stock Awards granted under the 2014 Plan vest at the rate specified by the Plan administrator. Initial grants of Stock Awards made to employees and non-employee consultants generally vest as to 25% on the first anniversary of the date of grant and the balance ratably over the next 36 months and subsequent grants generally vest monthly over a period of four years from the grant date, or upon the probable achievement of corporate goals. Stock options initially granted to members of the Company’s Board of Directors generally vest over a period of three years in equal quarterly installments from the date of the grant, subject to the option holder’s continued service as a director through such date. Subsequent grants to directors that are made automatically at Annual Meetings of Stockholders vest fully on the earlier of the first anniversary of the date of grant and the next Annual Meeting of Stockholders. The Plan administrator determines the term of Stock Awards granted under the 2014 Plan up to a maximum of ten years.

The aggregate number of shares of the Company’s common stock reserved for issuance under the 2014 Plan has automatically increased on January 1 of each year, beginning on January 1, 2015 and continued to increase on January 1 of each year through and including January 1, 2024, by 3% of the total number of shares of the Company’s capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company’s Board of Directors. On January 1, 2024, the aggregate number of shares of common stock that may be issued pursuant to Stock Awards under the 2014 Plan automatically increased from 12,203,023 to 13,837,444. The maximum number of shares that may be issued pursuant to the exercise of incentive stock options under the 2014 Plan is 30,000,000 shares.

Restricted Stock Units

Under the 2014 Plan, there were no restricted stock units granted during the three months ended March 31, 2024. During the three months ended March 31, 2023, the Company granted 407,000 restricted stock units. No restricted stock units were granted under the 2019 Inducement Plan during the three months ended March 31, 2024 and 2023.

The weighted-average grant date fair value per share of restricted stock units granted to employees during the three months ended March 31, 2023 was $10.06.

As of March 31, 2024, the Company’s restricted stock units consist of time-based restricted stock units and performance-based restricted stock units. For time-based restricted stock units, the Company recognizes compensation expense associated with these restricted stock units ratably over the award’s vesting period following the grant date. For performance-based restricted stock units, vesting is contingent on the achievement of certain performance targets, subject to the recipient’s continuous service through each performance target. Recognition of compensation expense associated with these performance-based awards begins when, and to the extent, the performance criteria are probable of achievement and the employee has met the service conditions.

During the three months ended March 31, 2024 and 2023, the Company recognized compensation expense relating to restricted stock units as follows:

	Three Months Ended
	March 31,
	2024		2023
Research and development	$	255	$	179
General and administrative		1,357		453
Total restricted stock unit expense	$	1,612	$	632

A summary of restricted stock unit activity related to employees and non-employee members of the Company’s Board of Directors as of and for the three months ended March 31, 2024 is presented below:

		Weighted
	Number of	Average Grant
	Units	Date Fair Value
Outstanding, December 31, 2023	566,324	$	9.27
Awarded	—		—
Vested and released	(186,375)		11.04
Forfeited	(129,682)		10.57
Outstanding, March 31, 2024	250,267	$	7.28
Restricted stock units exercisable (vested and deferred), March 31, 2024	—

Stock Options

Under the 2014 Plan, the Company granted 1,875,125 and 1,449,154 stock options during the three months ended March 31, 2024 and 2023, respectively. No stock options were granted under the 2019 Inducement Plan during the three months ended March 31, 2024 and 2023. There was no stock compensation expense recognized for the stock options granted in the current period as these were performance-based options that were not probable of achievement as of March 31, 2024. The fair values of stock options granted during the three months ended March 31, 2024 and 2023 were estimated as of the dates of grant using the Black-Scholes option pricing model with the following assumptions:

	Three Months Ended
	March 31,
	2024	2023
Risk-free interest rate	4.12%	3.62% - 4.22%
Expected volatility	89.6%	76.3% - 81.3%
Expected dividend yield	0%	0%
Expected life of employee and Board options (in years)	6.25	6.25

The weighted-average grant date fair value per share of options granted to employees and non-employee members of the Company’s Board of Directors for their Board service during the three months ended March 31, 2024 and 2023 was $0.76 and $7.08, respectively. No options were granted to non-employee consultants during the three months ended March 31, 2024 and 2023.

During the three months ended March 31, 2024 and 2023, the Company recognized compensation expense relating to stock options as follows:

	Three Months Ended
	March 31,
	2024		2023
Research and development	$	504	$	1,480
General and administrative		1,229		1,241
Total stock option expense	$	1,733	$	2,721

A summary of stock option award activity related to employees, non-employee members of the Company’s Board of Directors and non-employee consultants as of and for the three months ended March 31, 2024 is presented below:

		Weighted
	Number of	Average Exercise
	Shares	Price
Outstanding, December 31, 2023	7,897,647	$	12.99
Granted	1,875,125		0.99
Exercised	—		—
Forfeited	(679,165)		10.87
Expired	(277,075)		13.36
Outstanding, March 31, 2024	8,816,532	$	10.59
Options exercisable, March 31, 2024	4,827,562

The Company does not expect to realize any tax benefits from its stock option activity or the recognition of stock-based compensation expense because the Company currently has net operating losses and has a full valuation allowance against its deferred tax assets. Accordingly, no amounts related to excess tax benefits have been reported in cash flows from operations for each of the three months ended March 31, 2024 and 2023.