In September 2023, the Company adopted the 2023 Equity Incentive Plan (2023 Plan). The 2023 Plan provides for the grant of stock options, restricted stock awards, restricted stock unit awards, and other stock-based awards to employees, directors, and non-employee service providers of the Company. The 2023 Plan replaced the Company’s 2020 Equity Incentive Plan (2020 Plan). The Company no longer grants stock options or other awards under its 2020 Plan, but any stock options outstanding under the 2020 Plan remain outstanding and effective in accordance with their terms. Awards granted under the 2023 Plan expire no later than ten years from the date of grant. The price of stock options shall not be less than 100% of the estimated fair value on the date of grant and typically vest over a four-year period although may be granted with different vesting terms.

The 2023 Plan provides for an annual increase, to be added on the first day of each fiscal year, by up to 5% of the Company’s outstanding shares of common stock as of the last day of the prior year. On January 1, 2025, the number of shares of common stock available for issuance under the 2023 Plan increased by 8,085,495 shares as a result of the automatic increase provision of the 2023 Plan.

In September 2023, the Company adopted the 2023 Employee Share Purchase Plan (ESPP). The Company may hold one or more offering periods each year during which employees will be able to purchase shares under the ESPP through payroll deductions made over the term of the offering. The per-share purchase price at the end of each offering period is equal to the lesser of 85% of the closing price of the Company's common stock at the beginning or end of the offering period. On January 1, 2025, the number of shares of common stock available for issuance under the ESPP increased by 1,617,099 shares as a result of the automatic increase provision of the ESPP. In May 2025, 97,005 shares were issued under the ESPP.

Stock Option Activity


	Outstanding Stock Options			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
	(in thousands, except per share amounts and years)
Outstanding as of December 31, 2024		13,927		$	9.20		7.8	$	44,953
Granted		13,162			1.63
Exercised		—			—
Canceled and forfeited		(3,443	)		8.44
Expired		(197	)		5.74
Outstanding as of June 30, 2025		23,449		$	5.07		8.7	$	—
Exercisable as of June 30, 2025		7,218		$	7.69		7.4	$	—

The stock option activity table above excludes options to purchase 446,068 shares of common stock that were originally granted with market conditions to one of the Company’s executives.

On February 13, 2025 (Effective Date), the Company’s Board of Directors approved an option repricing (the Repricing) of the outstanding stock options held by members of the Board, certain employees and other service providers, including the Company’s named executive officers, subject to shareholder approval, which was obtained at the Annual Meeting of Stockholders on May 28, 2025 (Modification Date). Under the Repricing, the exercise price of each outstanding stock option under the Company’s 2023 Plan and 2020 Plan with an exercise price per share greater than $0.72 (the closing trading price of a share of the Company’s common stock on the Nasdaq Stock Market on May 28, 2025) held by those individuals eligible for the Repricing was repriced to $0.72 per share.

Under the terms of the Repricing, a repriced option will revert to its original exercise price if certain events occur prior to the 18 month anniversary of the effective date

The Repricing resulted in $4.2 million of incremental stock compensation expense, which was calculated using the Black-Scholes option-pricing model. $2.4 million of the incremental compensation cost related to unvested stock options as of the Modification Date, will be recognized on a straight line basis over the remaining requisite service period of the respective option, and $1.8 million of incremental compensation cost related to vested stock options will be recognized on a straight line basis over the remaining vesting period of the repriced options.

Of the incremental compensation cost, $0.3 million was recognized in the three months ended June 30, 2025.

The Company’s Plans allow for the grant of restricted common stock and restricted stock units to certain employees, executives, non-employee scientific advisors, and third-party service providers. The restrictions lapse over time primarily according to service-based vesting conditions of each award. In the event of a voluntary or involuntary termination of the holder’s continuous provision of services to the Company, any unvested portion of the restricted stock award is automatically forfeited.

The following table summarizes the Company’s restricted stock activity:


	Shares of Restricted Common Stock			Weighted- Average Grant Date Fair Value Per Share		Shares of Restricted Stock Units			Weighted- Average Grant Date Fair Value Per Share
	(in thousands, except per share amounts)
Outstanding and unvested as of December 31, 2024		371		$	10.82		1,441		$	17.32
Granted		—		$	—		—		$	—
Vested		(42	)	$	12.49		(370	)	$	15.86
Forfeited and expired		—		$	—		—		$	—
Cancelled		(231	)	$	8.87		(407	)	$	17.37
Outstanding and unvested as of June 30, 2025		98		$	14.67		664		$	18.07

The following table summarizes total stock-based compensation included in the Company’s condensed consolidated statements of operations and comprehensive loss:


	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2025		2024		2025		2024
Research and development	$	1,672	$	7,152	$	5,420	$	9,964
General and administrative		5,493		5,616		11,069		10,177
Total stock-based compensation	$	7,165	$	12,768	$	16,489	$	20,141

As of June 30, 2025, there was $57.7 million and $11.9 million of unrecognized stock-based compensation related to stock options and restricted stock outstanding, respectively, including stock options and restricted common stock for which achievement of milestones was not probable, which were expected to be recognized over a weighted-average remaining service period of 2.4 years and 2.5 years, respectively.