Stock-Based Compensation

12 Months Ended

Dec. 31, 2025

Stock-Based Compensation

Stock-Based Compensation

6. Stock-Based Compensation

The following table summarizes total stock-based compensation expense recognized for the years ended December 31, 2025 and 2024 (in thousands).


		For the years ended
		December 31,
		2025			2024
Research and development		$	1,167		$	3,112
General and administrative			40			344
Total stock-based compensation expense		$	1,207		$	3,456

The total unrecognized compensation cost was approximately $0.8 million as of December 31, 2025 and will be recognized over the next 1.5 years.

Stock Options

Equity Compensation Plan

On May 29, 2020, the Board of Directors of the Company approved a new equity compensation plan (the “Plan”). The Company’s prior plan was adopted in 2007, was updated in amended and restated plans that were approved by shareholders in 2012 and 2013 and expired in 2017 (the “Prior Plan”).

The Plan is substantially similar to the Prior Plan. The Plan has a 10-year life, and allows for awards to employees, directors and consultants of the Company. The Plan allows for any type of equity security to be awarded, as did the Prior Plan. The awards and their terms (including vesting) will be determined by the Board and applicable Committees, as was the case under the Prior Plan. The Plan established a pool of potential equity compensation equal to twenty percent of the outstanding securities of the Company, which is on an evergreen basis as under the Prior Plan.

On February 25, 2022, the Company amended its existing Equity Compensation Plan, which was adopted in 2020 as previously reported. The amendment provides that the possible forms of awards under the Plan include awards paid in cash or awards paid in a combination of cash and equity, in addition to the existing provisions for awards made in any form of equity. The amendment also clarifies that a delegation of authority from the Board to a Committee may be either a general delegation or a delegation for a specific occasion.

The following table summarizes stock option activity for the Company’s option plans during the years ended December 31, 2025 and 2024 (in thousands, except per share amounts):


							Weighted
				Weighted			Average
				Average			Remaining		Total
		Number of		Exercise			Contractual		Intrinsic
		Shares		Price			Life (in years)		Value
Outstanding as of January 1, 2024		317,076		$	0.35		6.0		$	114,097
Granted ⁽¹⁾		500			0.53		3.4			—
Cashless exercised		(650)			0.35		—			—
Expired		(100)			0.83		—			—
Outstanding as of December 31, 2024		316,826			0.35		5.0			3,932
Granted ⁽²⁾		2,275			0.29		5.5			—
Forfeited ⁽³⁾		(7,333)			0.26		—			—
Outstanding as of December 31, 2025		311,768		$	0.35		4.0		$	10
Options vested ⁽⁴⁾		278,109		$	0.33		4.0		$	10

(1)	During the year ended December 31, 2024, the Company granted 500,000 stock options with an exercise price at $0.53 per share to a staff employee. The options vested immediately on the grant date. In addition, the Company will make an additional payment of

$0.30 per option exercised by the employee for a maximum amount of $150,000. The Company has fully accrued this additional payment as of December 31, 2025 on its consolidated balance sheets.

(2)	During the year ended December 31, 2025, the Company granted 2 million stock options to a new-hire employee, of which 1.8 million options were forfeited in the same period. The Company also granted 0.3 million options to key external consultants who provide services to the Company.

(3)	As part of the Advent acquisition, 5.5 million stock options that were previously issued to Advent as compensation for services were returned to the Company and cancelled. These options were fully vested as of the date of the acquisition of Advent.

(4)	Of the total 278 million vested options, 183 million are subject to agreements (the “Blocker Letter Agreements”) under which they cannot be exercised except upon at least 61 days’ prior notice.

The Black-Scholes option pricing model is used to estimate the fair value of stock options granted. The weighted average assumptions used in calculating the fair values of stock options that were granted during the years ended December 31, 2025 and 2024:


		For the years ended
		December 31,
		2025			2024
Exercise price		$	0.29		$	0.53
Expected term (years)			3.2			2.1
Expected stock price volatility			77	%		73	%
Risk-free rate			3.8	%		4.5	%
Dividend yield (per share)			0	%		0	%

Other Service Agreements

During year ended December 31, 2025, the Company issued 150,000 shares of common stock to an unrelated vendor who provided professional services for the Company. The fair value of the common stock on the issuance date was approximately $39,000, which was expensed immediately on the issuance date.

During the year ended December 31, 2024, the Company issued 350,000 shares of common stock to an unrelated vendor who provided professional services for the Company. The fair value of the common stock on the issuance date was approximately $0.2 million, which was expensed over a three-month service period.