Stock-based Compensation

6 Months Ended

Jun. 30, 2026

Share-Based Payment Arrangement [Abstract]

9. Stock-based Compensation

Stock‑based compensation expense recognized was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Research and development	$	878	$	596	$	1,143	$	1,164
General and administrative		2,303		1,001		2,700		2,070
Total stock-based compensation expense	$	3,181	$	1,597	$	3,843	$	3,234

Valuation Assumptions

The fair value of stock options was determined using the Black-Scholes option-pricing model and the assumptions below. Each of these inputs is subjective and generally required significant judgment.

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Fair Value of Common Stock—The fair value of each share of common stock is based on the closing price of the Company’s common stock on the date of grant, or other relevant determination date, as reported on The Nasdaq Capital Market.

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Risk-Free Interest Rate—The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of the option.

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Expected Volatility—Because the Company was previously privately held and did not have any trading history for its common stock, the expected volatility was estimated based on the average volatility for comparable publicly traded life sciences companies over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on the similar size, stage in life cycle or area of specialty. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available.

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Expected Term—The expected term represents the period that the stock-based awards are expected to be outstanding and is determined using the simplified method (based on the midpoint between the vesting date and the end of the contractual term) as the Company has limited history of relevant stock option exercise activity.

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Expected Dividend Yield—The Company has never paid dividends on its common stock and has no plans to pay dividends going forward. Therefore, it used an expected dividend yield of zero.

The fair value of each stock option was estimated using the Black‑Scholes option‑pricing model with the following weighted-average assumptions:


	Six Months Ended June 30,
	2026			2025
Risk-free interest rate		4.00	%		3.98	%
Expected volatility		105.98	%		100.54	%
Expected term (in years)		5.98			5.97
Expected dividend yield		—			—

The grant date fair value of RSUs is based upon the fair market value of the Company’s common stock based on its closing price as reported on the date of grant on the Nasdaq Capital Market.

The fair value of options granted during the six months ended June 30, 2026 and 2025 was $35.8 million and $0.4 million, respectively. The fair value of RSUs granted during the six months ended June 30, 2026 was $1.6 million.

Stock Option Activity

Changes in shares available for grant under the 2026 Plan, the 2020 Plan, and the 2024 Inducement Plan during the six months ended June 30, 2026 were as follows:


	Shares Available for Grant
Shares available for grant at December 31, 2025		98,723
2020 Plan reserve increase on January 1, 2026		323,000
Options and restricted stock units granted		(4,748,364	)
Options and restricted stock units forfeited, cancelled, or expired		2,090
Termination of future use of 2020 Plan		(355,345	)
Shares reserved for issuance under 2026 Plan		5,700,000
Shares available for grant at June 30, 2026		1,020,104

A summary of stock option activity under the 2026 Plan, the 2020 Plan, and the 2024 Inducement Plan for the six months ended June 30, 2026 is as follows:


	Shares			Weighted- Average Exercise price per Share		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Balance at December 31, 2025		1,204,829		$	37.44	8.14		$	2,030
Granted		4,583,364			9.43		—		—
Exercised		—			—		—		—
Forfeited/expired		(2,090	)		3.13		—		—
Balance at June 30, 2026		5,786,103		$	15.27		9.34	$	3,388
Expected to vest		4,964,270		$	9.39		9.69	$	2,731
Options exercisable		821,833		$	50.80		7.25	$	656

The total fair value of options granted that vested during the six months ended June 30, 2026 and 2025 was $2.4 million and $4.7 million, respectively.

The aggregate intrinsic value in the table above is calculated as the difference between the exercise price of the underlying options and the estimated fair value of the Company’s common stock underlying all options that were in-the-money at June 30, 2026. There were no options exercised during the six months ended June 30, 2026 and 2025. As of June 30, 2026, there was

$37.1 million of total unrecognized compensation cost related to non-vested stock options. The Company expects to recognize this cost over a remaining weighted-average period of 3.37 years. The Company utilizes newly issued shares to satisfy option exercises.

Stock options outstanding and exercisable under the 2026 Plan, the 2020 Plan, and the 2024 Inducement Plan consisted of the following at June 30, 2026



Exercise Price ($)	Options Outstanding		Options Exercisable
3.13 to 7.14		628,261		131,881
8.35 to 13.5		4,535,226		167,825
20.4 to 40.10		411,024		310,535
89.3 to 294.10		211,592		211,592
Total		5,786,103		821,833

Restricted Stock Unit Activity

A summary of restricted stock unit ("RSU") activity under the 2026 Plan and the 2020 Plan for the six months ended June 30, 2026 is as follows:


	Share Equivalent			Weighted- Average Grant Date Fair Value
Non-vested at December 31, 2025		57,601		$	3.76
Granted		165,000			9.54
Cancelled		—			—
Vested		(57,601	)		3.76
Non-vested at June 30, 2026		165,000		$	9.54

As of June 30, 2026, there was $1.6 million of total unrecognized compensation costs related to non-vested RSUs. The Company expects to recognize this cost over a remaining weighted-average period of 0.42 years.