Stock-Based Compensation (Tables)
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12 Months Ended |
Dec. 31, 2025 |
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| Stock-Based Compensation [Abstract] |
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| Components of Stock-Based Compensation Expense |
Following is the stock-based compensation expense related to common stock options, restricted common stock, common stock warrants and deferred stock units:
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| Year Ended
December 31, | |
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| 2025 | |
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| 2024 | |
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Research and development
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$ |
732 | |
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$ |
1,222 | |
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General and administrative
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924 | |
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1,225 | |
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Total stock-based compensation expense
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$ |
1,656 | |
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$ |
2,447 | |
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| Weighted Average Assumptions Used to Determine Fair Value of Options Granted |
The fair value of the options granted is determined using the Black-Scholes option-pricing model. The following weighted average assumptions were used:
| | | | | | | | | | | | | | 2025 | | | | 2024 | | | Risk-free interest rate | | | 4.48 | % | | | 3.89 | % | | Expected life of the options | | | 5.6 years | | | | 5.7 years | | | Expected volatility of the underlying stock | | | 83.1 | % | | | 75.1 | % | | Expected dividend rate | | | 0 | % | | | 0 | % |
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| Stock Option Activity |
The following table summarizes the stock option activity in the stock-based compensation plans:
| | | | | | | | | | | | | | | | | | | | | Number of Shares | | | Weighted Average
Exercise
Price | | | Weighted Average Remaining Contractual
Life
(in years) | | | Aggregate Intrinsic Value
(in thousands) | | | Outstanding, December 31, 2023 | | | 6,333,841 | | | $ | 2.66 | | | | | | | | | | | Granted | | | 1,373,000 | | | | 1.86 | | | | | | | | | | | Forfeited/Cancelled | | | (348,750 | ) | | | 6.35 | | | | | | | | | | | Exercised | | | (503,333 | ) | | | 1.71 | | | | | | | | | | | Outstanding, December 31, 2024 | | | 6,854,758 | | | $ | 2.39 | | | | | | | | | | | Granted | | | 1,211,000 | | | | 1.23 | | | | | | | | | | | Forfeited/Cancelled | | | (403,085 | ) | | | 1.76 | | | | | | | | | | | Exercised | | | (1,090,164 | ) | | | 2.05 | | | | | | | | | | | Outstanding, December 31, 2025 | | | 6,572,509 | | | $ | 2.27 | | | | 5.58 | | | $ | 13,031 | | | Exercisable, December 31, 2025 | | | 6,237,508 | | | $ | 2.60 | | | | 5.42 | | | $ | 12,155 | |
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| Outstanding and Exercisable Options under Stock Based Compensation Plans |
The following table summarizes additional information regarding outstanding and exercisable options under our stock-based compensation plans at December 31, 2025:
| | | | Options Outstanding | | | Options Exercisable | | | Exercise Price (Range) | | | Number of
Shares | | | Weighted
Average
Remaining
Contractual
Life | | | Weighted
Average
Exercise
Price | | | Number of
Shares | | | Weighted
Average
Exercise
Price | | | | | |
| | | (in years) | | | | | | | | | | | | | | | $0.89 – 1.50 | | | 1,771,541 | | | | 7.10 | | | $ | 1.19 | | | | 1,536,540 | | | $ | 1.19 | | | $1.51 – 2.50 | | | 3,022,227 | | | | 5.85 | | | | 2.00 | | | | 2,922,227 | | | | 2.00 | | | $2.51 – 5.00 | | | 1,558,741 | | | | 3.82 | | | | 3.47 | | | | 1,558,741 | | | | 3.47 | | | $5.01 – 6.71 | | | 220,000 | | | | 2.10 | | | | 5.92 | | | | 220,000 | | | | 5.92 | | | | | | 6,572,509 | | | | 5.58 | | | $ | 2.39 | | | | 6,138,254 | | | $ | 2.45 | |
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