| Schedule of Stock Option Activities |
The following table summarizes the stock option activities, including performance-based stock options, under the 2024 Plan, the 2021 Equity Incentive Plan (the “2021 Plan”), the 2022 Inducement Plan and the 2019 EIP for the six months ended June 30, 2026: | | | Options
Outstanding | | | Weighted
Average
Exercise
Price | | | Weighted Average
Remaining
Contractual
Life (Years) | | | Aggregate
Intrinsic Value
(in thousands) | | | Balance, December 31, 2025 | | | 2,246,206 | | | $ | 13.72 | | | | 4.81 | | | $ | — | | | Options granted | | | 1,262,300 | | | $ | 1.65 | | | | | | | | | | | Options cancelled/forfeited/expired | | | (1,122,407 | ) | | $ | 8.23 | | | | | | | | | | | Balance, June 30, 2026 | | | 2,386,099 | | | $ | 9.92 | | | | 7.15 | | | $ | — | | | Vested and expected to vest, June 30, 2026 | | | 2,386,099 | | | $ | 9.92 | | | | 7.15 | | | $ | — | | | Exercisable, June 30, 2026 | | | 959,629 | | | $ | 18.33 | | | | 4.21 | | | $ | — | | The following table provides a summary of performance-based stock options activity under the 2024 Plan and the 2021 Plan during the six months ended June 30, 2026: | | | Options
Outstanding | | | Weighted
Average
Exercise
Price | | | Weighted
Average
Remaining
Contractual
Life (Years) | | | Aggregate
Intrinsic
Value
(in thousands) | | | Balance, December 31, 2025 | | | 30,894 | | | $ | 7.33 | | | | 4.43 | | | $ | — | | | Options expired | | | (14,616 | ) | | | 7.10 | | | | | | | | | | | Balance, June 30, 2026 | | | 16,278 | | | $ | 7.53 | | | | 3.95 | | | $ | — | | | Vested and expected to vest, June 30, 2026 | | | 16,278 | | | $ | 7.53 | | | | 3.95 | | | $ | — | | | Exercisable, June 30, 2026 | | | 16,278 | | | $ | 7.53 | | | | 3.95 | | | $ | — | |
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| Schedule of RSU Activity |
The following table provides a summary of RSU activity under the 2024 Plan during the six months ended June 30, 2026: | | | Number of
Shares | | | Weighted-
Average
Grant Date
Fair Value | | | Unvested restricted stock units at December 31, 2025 | | | 198,900 | | | $ | 6.00 | | | Vested | | | (69,750 | ) | | $ | 6.00 | | | Forfeited | | | (60,300 | ) | | $ | 6.00 | | | Unvested restricted stock units at June 30, 2026 | | | 68,850 | | | $ | 6.00 | |
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| Schedule of Stock-Based Compensation Expenses |
The following table presents stock-based compensation expenses related to options, PSUs and RSUs granted to employees and non-employees, employee stock purchase plan awards and restricted common stock shares issued to founders (in thousands): | | | Three Months Ended
June 30, | | | Six Months Ended
June 30, | | | | | 2026 | | | 2025 | | | 2026 | | | 2025 | | | General and administrative | | $ | 579 | | | $ | 1,274 | | | $ | 781 | | | $ | 2,514 | | | Research and development | | | 185 | | | | 543 | | | | 406 | | | | 1,114 | | | Total | | $ | 764 | | | $ | 1,817 | | | $ | 1,187 | | | $ | 3,628 | |
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| Schedule of Fair Value of Stock Options Was Estimated Using a Black-Scholes Option-Pricing Model |
The grant date fair value of stock options was estimated using a Black-Scholes option-pricing model with the following assumptions: | | | Three Months Ended
June 30, | | | Six Months Ended
June 30, | | | | | 2026 | | | 2025 | | | 2026 | | | 2025 | | | Expected term (in years) | | | — | | | | 6.06-6.08 | | | | 6.08 | | | | 6.01-6.08 | | | Expected volatility | | | — | | | | 98.13%-98.14% | | | | 99.87%-100.05% | | | | 97.37%-98.14% | | | Risk-free interest rate | | | — | | | | 3.83%-4.04% | | | | 3.85%-3.88% | | | | 3.83%-4.35% | | | Expected dividend yield | | | — | | | | — | | | | — | | | | — | | | | | | Three and Six
Months Ended
June 30, | | | | | | 2025 | | | Expected term (in years) | | | 0.49-2.00 | | | Expected volatility | | | 104.93%-155.78 | % | | Risk-free interest rate | | | 3.94%-4.31 | % | | Expected dividend yield | | | — | |
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