The Company has a 2013 Stock Option Plan (the “2013 Plan”), which is administered by the Compensation Committee. Under the 2013 Plan, stock options to purchase shares of common stock could be granted to eligible employees, officers, directors and consultants of the Company.

In 2021, the Company replaced the 2013 Plan with the 2021 Stock Incentive Plan (the “2021 Plan”), authorizing the granting of equity awards for the issuance of up to 120,000 shares of common stock. Upon adoption of the 2021 Plan, no more shares would be issued under the 2013 Plan. Starting on January 1, 2022, the shares authorized under the 2021 Plan shall have an annual increase of the lesser of (a) 3.5% of the aggregate number of shares of common stock outstanding on the final day of the preceding calendar year, or (b) such smaller amount as determined by the Board. On January 1 of 2023, 2024, 2025 and 2026, an additional 9,548, 19,193, 21,172 and 88,357 shares, respectively, were authorized under the 2021 Plan. On June 16, 2026, the Company’s stockholders approved an amendment to the 2021 Plan to increase the number of shares of common stock available for sale under the Plan by 150,000. As of June 30, 2026, 238,899 shares were available for issuance under the 2021 Plan.


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Research and development	$	150	$	263	$	299	$	423
General and administrative	237		381		475		656
Total stock-based compensation expense	$	387	$	644	$	774	$	1,079

In April 2026, the Company’s CEO was issued 37,749 shares of fully vested common stock under the 2021 Plan in partial satisfaction of his 2025 bonus payment in lieu of cash. The common shares were issued at $6.11 per share for a total value of $0.2 million.


	Six Months Ended June 30,
	2026	2025
Stock price	n/a	$14.25
Exercise price	n/a	$14.25
Expected volatility	n/a	106.8% to 107.9%
Risk free interest rates	n/a	4.1% to 4.6%
Expected term (years)	n/a	6.5 to 7

For the six months ended June 30, 2025, a dividend yield of 0% was used because the Company has not historically paid and does not intend to pay a dividend on common stock in the foreseeable future. The expected stock price volatility assumption was estimated based on the historical volatilities for industry peers, as the Company had no active market for its stock prior to the initial public offering (“IPO”) and limited history for issuance price of its stock. The risk-free rate assumption is determined using the yield currently available on U.S. Treasury zero coupon issues with a remaining term commensurate with the expected term of the award. The expected term of the option represents the period the options are expected to be outstanding.


	Options	Weighted- Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2025	160,428	$	102.46	7.8	$	—
Issued	—	$	—
Exercised	—	$	—
Forfeited and cancelled	(2,800)	$	100.00
Outstanding at June 30, 2026	157,628	$	102.50	7.5	$	—
Exercisable at June 30, 2026	98,372	$	131.09	6.8	$	—

All options expire 10 years from date of grant. Options outstanding begin to expire in September 2026. Options that were granted to employees and consultants have vesting periods that vary by award to recipient and range from immediate vesting to a period of up to 4 years.

As of June 30, 2026, total unrecognized compensation cost related to options was approximately $2.0 million and is expected to be recognized over the remaining weighted average service period of 1.8 years.


	Six Months Ended June 30,
	2026	2025
Stock price	n/a	$7.50 to $18.75
Exercise price	n/a	$9.50 to $21.25
Expected volatility	n/a	96.3% to 103.8%
Risk free interest rates	n/a	3.87% to 3.91%
Expected term (years)	n/a	1.5 to 5

For the six months ended June 30, 2025, a dividend yield of 0% was used because the Company has not historically paid and does not intend to pay a dividend on common stock in the foreseeable future. The expected stock price volatility assumption was estimated based on the historical volatilities for industry peers, as the Company had no active market for its stock prior to the IPO and limited history for issuance price of its stock. The risk-free rate assumption is determined using the yield currently available on U.S. Treasury zero coupon issues with a remaining term commensurate with the expected term of the award. The expected term of the warrant represents the period the warrants are expected to be outstanding.


	Warrants	Weighted- Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2025	339,298	$	40.11	3.0	$	13
Issued	—	$	—
Exercised	—	$	—
Forfeited and cancelled	(3,640)	$	242.17
Outstanding at June 30, 2026	335,658	$	37.92	2.4	$	—
Exercisable at June 30, 2026	335,037	$	37.71	2.4	$	—

As of June 30, 2026, total unrecognized compensation cost related to warrants was approximately $0.1 million and is expected to be recognized over the remaining weighted average service period of 1.4 years.