The Company currently grants equity-based awards under its 2020 Incentive Award Plan (“2020 Plan”) and the 2022 Employment Inducement Award Plan (“Inducement Award Plan”). The Company previously granted equity-based awards under its 2005 Equity Incentive Plan (“2005 Plan”) and 2016 Equity Incentive Plan ("2016 Plan”).

The 2020 Plan provides for grant of incentive stock options and nonqualified stock options, stock appreciation rights, restricted stock, dividend equivalents, restricted stock units, performance awards and other share and cash-based awards to employees and consultants and members of the Board of Directors of the Company and its subsidiary.

The initial number of shares of the Company’s common stock that may be issued under the 2020 Plan is 2,100,000 shares plus the number of shares of the Company’s common stock underlying outstanding awards under the 2005 Plan and 2016 Plan as of the effective date of the 2020 Plan that expire, lapse or are terminated, exchanged for cash, surrendered, repurchased, canceled or forfeited following the effective date of the 2020 Plan. The number of shares available under the 2020 Plan will automatically increase on January 1st of each year from 2021 to 2030 by the lesser of (i) 4% of the number of shares of common stock outstanding on the final day of the immediately preceding calendar year and (ii) a smaller number of shares determined by the Company’s Board of Directors. However, no more than 8,800,000 shares may be issued under the 2020 Plan pursuant to the exercise of incentive stock options. On January 1, 2023, the shares available for grant under the 2020 Plan was automatically increased by 1,273,106. On January 1, 2024, the shares available for grant under the 2020 Plan was automatically increased by 2,288,582. As of December 31, 2024, the Company had 696,925 shares available for issuance under the 2020 Plan. On January 1, 2025, the shares available for grant under the 2020 Plan was automatically increased by 2,620,600.

In February 2022, the Company’s Board of Directors adopted the Inducement Award Plan (and together with the 2020 Plan, 2016 Plan and 2005 Plan, the “Plans”), which was adopted by the Board of Directors without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Stock Market LLC listing rules (“Rule 5635(c)(4)”), and currently allows for the granting of up to 2,763,002 shares of the Company's common stock. The Inducement Award Plan provides for the grant of non-qualified stock options, stock appreciation rights, performance units, restricted stock awards, restricted stock units and stock grants. In accordance with Rule 5635(c)(4), awards made under the Inducement Award Plan may only be made to a newly hired employee who has not previously been a member of the Board, or any employee who is being rehired following a bona fide period of non-employment by the Company or a subsidiary, as a material inducement to the employee’s entering into employment with the Company or its subsidiary. In June 2022, the Inducement Award Plan was amended to

increase the shares authorized for issuance thereunder to 1,473,002 shares and amended again in the same month to increase the shares authorized for issuance to 1,703,002. In September 2022, the Inducement Award Plan was amended to increase the shares authorized for issuance to 1,813,002 shares. On December 9, 2022, the Inducement Award Plan was amended and restated to increase the shares authorized for issuance to 2,413,002 shares. The amended and restated Inducement Award Plan was amended in October 2023 to add another 350,000 shares to the shares authorized for issuance, for a current overall limit of 2,763,002 shares. During the year-ended December 31, 2024, the Company did not grant options to purchase shares of common stock to executives under the amended and restated Inducement Award Plan, and during the year-ended December 31, 2023 the Company granted options to purchase 630,000 shares under this plan. There were 863,000 shares remaining available for issuance under the Inducement Award Plan as of December 31, 2024.

All stock option grants are nonqualified stock options except for option grants to employees granted, under the 2020 Plan, 2016 Plan or 2005 Plan intended to qualify as incentive stock options under the Internal Revenue Code of 1986, as amended. Stock options may not be granted under the 2020 Plan at less than the fair market value of the Company’s common stock on the date of grant. Vesting periods of awards are determined by the Board of Directors or its compensation committee. Vesting periods of awards granted to date range from vesting upon grant to vesting over a four-year period. Vesting conditions are generally based on continued service. Additionally, the Company has granted certain awards which vest upon the achievement of certain financing and revenue milestones. Stock options granted under the Plans expire no more than 10 years from the date of grant.

Stock-based compensation expense included in the Company’s consolidated statements of operations and comprehensive loss was as follows (in thousands):


	Year Ended December 31,
	2024		2023
Research and development	$	1,360	$	1,176
General and administrative		5,356		4,711
Total	$	6,716	$	5,887

For the year ended December 31, 2024 no stock-based compensation expense was recorded to liabilities. For the year ended December 31, 2023, $255,000 of the stock-based compensation expense was recorded to liabilities.

The Company has granted options to purchase 1,648,002 shares of common stock that vest as to one-third of options, in each case, upon the achievement of three distinct market capitalization targets during the five-year performance period following the date of grant, provided that no more than one-third of the option may vest prior to the first anniversary of the date of grant, no more than two-thirds of the option may vest prior to the second anniversary of the date of grant and the option may not become fully vested prior to the third anniversary of the date of grant, subject to continued service on each applicable vesting date and certain exceptions in the context of a change in control transaction. The Company has accounted for these awards as market-based condition awards and therefore, stock-based compensation recorded during the year ended December 31, 2024 was $1.0 million.

In March 2024, the Company granted options to purchase 550,000 shares of common stock at an exercise price of $6.07 per share to its Chief Executive Officer (“2024 Performance Options”) and granted 385,000 RSUs to its Executive Chair (“2024 PSUs”), each with performance-based vesting conditions under the 2020 Plan. Vesting of the 2024 Performance Options and the 2024 PSUs are based on the achievement of various clinical and regulatory milestones during the specified periods.

For the 2024 PSUs, the Company measures stock compensation expense based on the fair value of the award on the grant date and then once the Company determines the performance criteria is probable of achievement, recognizes such amount over the vesting term of the award, which is approximately 3.8 years. The Company determined the fair value of the 2024 Performance Option using the Black-Scholes option-pricing model and using the following inputs: risk-free interest rate of 4.26%, volatility of 76.82%, expected dividend yield 0%, and expected term of 6.0 years.


	Shares			Weighted- Average Grant Date Fair Value
Restricted stock units outstanding as of December 31, 2023		105,048		$	3.20
Granted		2,332,527		$	2.82
Vested		(86,574	)	$	4.26
Forfeited		(207,199	)	$	4.29
Restricted stock units outstanding as of December 31, 2024		2,143,802		$	2.65

The following table summarizes the Company’s unrecognized stock-based compensation as of December 31, 2024:


	Unrecognized Expense (in thousands)		Period of Recognition (years)
Restricted stock units	$	2,088		2.4
Stock options		5,743		2.7
Total	$	7,831


	Year Ended December 31,
	2024			2023
Risk-free interest rate		4.2	%		3.9	%
Expected dividend yield		—	%		—	%
Expected term (in years)		6.0			6.1
Expected volatility		80.5	%		82.7	%

A summary of the stock option activity, including incentive options, under the Plans for the year ended December 31, 2024 was as follows:


	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2023		5,709,980		$	5.68		8.0	$	6,334
Granted		2,605,002			4.89
Exercised		(1,002	)		3.96
Cancelled		(1,999,419	)		4.69
Outstanding at December 31, 2024		6,314,561		$	5.66		7.5	$	—
Exercisable at December 31, 2024		2,822,175		$	7.06		6.8	$	—
Vested and expected to vest at December 31, 2024		6,314,561		$	5.66		7.5	$	—

The weighted-average fair value of options granted to employees, directors and non-employees during the years ended December 31, 2024 and 2023 was $2.80 and $2.13, respectively.

The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2024 and 2023 was approximately $0.1 million and $0.1 million, respectively.

In April 2020, the Company’s Board of Directors adopted the Company’s 2020 Employee Stock Purchase Plan (“2020 ESPP”). The 2020 ESPP is structured as a qualified employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986, as amended, and is not subject to the provisions of the Employee Retirement Income Security Act of 1974. The Company initially reserved 150,000 shares of common stock for issuance under the 2020 ESPP. In addition, the number of shares available for issuance under the 2020 ESPP will be annually increased on January 1st of each year from 2021 to 2030 by the lesser of (i) 0.5% of the number of shares of common stock outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares as is determined by the Company’s Board of Directors, provided that no more than 987,500 shares of common stock may be issued under the 2020 ESPP.

On January 1, 2023, the shares available for grant under the 2020 ESPP was automatically increased by 159,138. On January 1, 2024, the shares available for grant under the 2020 ESPP was automatically increased by 286,072. The 2020 ESPP permits eligible participants to purchase common stock through payroll deductions of up to a specified percentage of their eligible compensation. The purchase price of the shares, in the absence of a contrary designation, will be 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the purchase date. In June 2024 the Company indefinitely suspended the offering of its 2020 ESPP. As of December 31, 2024, 1,000 shares have been issued under the 2020 ESPP. As of December 31, 2024, there are a total of 723,906 shares available for issuance under the 2020 ESPP. On January 1, 2025, the shares available for grant under the 2020 ESPP was automatically increased by 262,594.