v3.26.1
Stock-Based Compensation Plans (Tables)
 3 Months Ended
Mar. 31, 2026
Share-Based Payment Arrangement [Abstract]  
Schedule of Stock Option Activity
The following table summarizes stock option activity for the three months ended March 31, 2026 and 2025, respectively, for the 2019 Plan:
OptionsWeighted-
Average
Exercise
Price		Weighted-
Average
Remaining
Contractual
Term (Years)		Aggregate
Intrinsic
Value
Outstanding as of January 1, 20262,572,850 $12.08 
Granted19,000 $8.36 
Exercised— $— 
Forfeited or expired(9,544)$8.81 
Outstanding as of March 31, 20262,582,306 $12.06 8.01$3,330,853 
Options exercisable as of March 31, 20261,128,145 $14.98 7.00$386,493 
OptionsWeighted-
Average
Exercise
Price		Weighted-
Average
Remaining
Contractual
Term (Years)		Aggregate
Intrinsic
Value
Outstanding as of January 1, 20251,613,605 $15.20 
Granted19,500 $10.20 
Exercised— $— 
Forfeited or expired(12,245)$15.70 
Outstanding as of March 31, 20251,620,860 $15.20 8.29$16,635 
Options exercisable as of March 31, 2025629,572 $18.40 7.14$3,397 
Schedule of Valuation Assumptions Used
The following table summarizes the key assumptions used in estimating the fair value of the SARs on March 31, 2026 and December 31, 2025:
March 31, 2026December 31, 2025
Expected term (years)
1.08-2.96
1.00-2.40
Risk-free interest rate
3.75%-4.21%
3.64%-4.11%
Stock price volatility
80%-115%
65%-115%
Probability (1)
50%-50%
50%-50%
Dividend rate
—%
—%

(1) Scenario probability was based on timing expectations of the Company that a corporate transaction occurring was estimated at 50%; and a corporate transaction not occurring at 50%.
The following are the underlying assumptions used in the Black-Scholes option pricing model to determine the fair value of stock options granted to employees and to non-
employees under this stock plan. The expected term of the options for the three months ended March 31, 2025 includes a grant to a non-employee consultant where the term of the option is five years compared to employee grants that are ten years:
Three Months Ended March 31,
20262025
Risk-free interest rate3.81%4.36%
Expected dividend yield0%0%
Expected volatility111.0%95.2%
Expected term of options (years)6.103.50
The following table summarizes the key assumptions used in estimating the fair value of the SARs at March 31, 2026 and December 31, 2025:

March 31, 2026December 31, 2025
Expected term (years)
1.08-2.96
1.00-2.40
Risk-free interest rate
3.75%-4.21%
3.64%-4.11%
Stock price volatility
80%-115%
65%-115%
Probability (1)
50%-50%
50%-50%
Dividend rate
—%
—%

(1) Scenario probability was based on timing expectations of the Company that a corporate transaction occurring was estimated at 50%; and a corporate transaction not occurring at 50%.
Schedule of SAR's Activity
The Company’s SARs activity is as follows:

SARs grantsSharesWeighted average exercise priceWeighted average remaining contractual term (years)Aggregate intrinsic value
Balance at January 1, 20261,623,007 $7.65
SARs granted— $—
SARs forfeited or expired(715,308)$7.65
SARs exercised— $—
Balance at March 31, 2026907,699 $7.659.23$3,131,563
Exercisable at March 31, 2026— $———
Schedule of Stock-Based Compensation Expense for Stock Awards Recognized
Total stock-based compensation expense for all stock awards recognized in the accompanying unaudited condensed consolidated statements of operations is as follows:
 Three Months
 Ended March 31,
 20262025
Research and development$1,483,000 $833,000 
General and administrative2,983,000 1,209,000 
Total$4,466,000 $2,042,000