v3.25.2
Equity Incentive Plans and Stock-based Compensation
6 Months Ended
Jun. 30, 2025
Share-Based Payment Arrangement [Abstract]  
Equity Incentive Plans and Stock-based Compensation Equity Incentive Plans and Stock-based Compensation
On June 8, 2021, the stockholders of the Company approved the 2021 Equity Incentive Plan (“2021 Plan”) and the 2021 Employee Stock Purchase Plan (“2021 ESPP”). As of June 30, 2025, 27,667,839 and 5,630,908 shares were available for grant under the 2021 Plan and 2021 ESPP, respectively.
2021 Employee Stock Purchase Plan
Under the 2021 ESPP, participants are permitted to purchase shares of Common Stock, up to the IRS allowable limit, through contributions (in the form of payroll deductions or otherwise to the extent permitted by the administrator of the 2021 ESPP) of up to 15% of their eligible compensation. Participants are permitted to purchase shares of the Company’s Common Stock at 85% of the lower of the fair market value of the Company’s Common Stock on the first trading day of an offering period or on the last trading date in each purchase period. The Company offers a six month purchase period. Participants may end their participation at any time during an offering and will be paid their accrued contributions that have not yet been used to purchase shares. Participation ends automatically upon termination of employment with the Company. The number of shares of common stock available for issuance under the 2021 ESPP will be increased on the first day of each fiscal year in an amount equal to the least of (i) 3,734,500 shares of common stock, (ii) a number of shares of common stock equal to one percent (1%) of the total number of shares of all classes of common stock of the Company on the last day of the immediately preceding fiscal year, or (iii) such number of shares determined by the Administrator no later than the last day of the immediately preceding fiscal year. On January 1, 2025, the number of shares available under the 2021 ESPP increased by 1,261,061 shares pursuant to this feature.
2021 Equity Incentive Plan
Under the 2021 Plan, the Company can grant incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units and performance awards to employees, non-employee
directors and consultants. Options generally expire ten years after the date of grant. The number of shares available for issuance under the 2021 Plan will be increased on the first day of each fiscal year in an amount equal to the least of (i) 18,672,200 shares, (ii) a number of shares equal to five percent (5%) of the total number of shares of all classes of common stock of the Company outstanding on the last day of the immediately preceding fiscal year, or (iii) such number of shares determined by the Administrator no later than the last day of the immediately preceding fiscal year. On January 1, 2025, the number of shares available under the 2021 Plan increased by 6,305,308 shares pursuant to this feature.
2017 Equity Incentive Plan
At the time of adoption of the 2021 Plan and the 2021 ESPP, no further awards will be granted under the 2017 Equity Incentive Plan (“2017 Plan”). Stock-based awards forfeited or cancelled from the 2017 Plan are returned to the pool of shares of Common Stock available for issuance under the 2021 Plan.
Grant Date Fair Value of Stock Options
In determining the compensation cost of the option awards, the fair value for each option award has been estimated using the Black Scholes model. The significant assumptions used in these calculations are summarized as follows:
Three Months Ended June 30,Six Months Ended June 30,
2025202420252024
Expected term (in years)
5.3 - 6.0
5.3 - 6.0
5.3 - 6.0
5.3 - 6.0
Expected volatility
97.5% - 103.0%
99.7% - 101.1%
97.5% - 103.0%
99.7% - 101.1%
Expected dividend rate0.0 %0.0 %0.0 %0.0 %
Risk free interest rate
3.90% - 4.04%
4.17% - 4.60%
3.90% - 4.04%
4.01% - 4.60%
Expected term: The expected term of stock options represents the weighted-average period the stock options are expected to remain outstanding. The Company does not have sufficient historical exercise and post-vesting termination activity to provide accurate data for estimating the expected term of options and has opted to use the “simplified method,” whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option.
Expected volatility: Historically, the Company has been a private company and lacked company‑specific historical and implied volatility information for its common stock. Therefore, the expected volatility of the Company’s common stock was determined by using an average of historical volatilities of selected industry peers deemed to be comparable to the Company’s business corresponding to the expected term of the awards and the Company expects to continue to do so until such time as the Company has adequate historical data regarding the volatility of its traded common stock price.
Expected dividend yield: The expected dividend rate is zero as the Company has no history or expectation of declaring dividends on its common stock.
Risk-free interest rate: The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities corresponding to the expected term of the awards.
The following table summarizes option award activity during the six months ended June 30, 2025:
Number of Stock Option AwardsWeighted Average Exercise PriceWeighted Average Remaining Contractual Life (Years)Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2024
16,634,775 $3.57 
Granted3,493,350 $0.99 
Exercised(60,433)$0.44 
Forfeited(1,071,442)$2.71 
Outstanding as of June 30, 2025
18,996,250 $3.16 7.4$330 
Options vested and expected to vest as of June 30, 2025
18,996,250 $3.16 
Vested and exercisable at June 30, 2025
11,777,364 $3.91 6.4$310 
As of June 30, 2025, there was $10.6 million of total unrecognized compensation expense expected to be recognized over a weighted average-period of 2.4 years. Aggregate intrinsic value represents the difference between the fair market value of the common stock and the exercise price of outstanding, in-the-money options.
Stock-based Compensation Expense
The following sets forth the total stock-based compensation expense included in the Company’s condensed consolidated statement of operations:
Three Months Ended June 30,Six Months Ended June 30,
(in thousands)2025202420252024
Research and development$686 $1,146 $1,454 $2,242 
General and administrative1,023 2,133 2,423 4,151 
Total stock-based compensation expense$1,709 $3,279 $3,877 $6,393