Share-based compensation is accounted for in accordance with the provisions of ASC 718, Compensation-Stock Compensation.

The Company has granted stock option awards to employees, directors and consultants from its 2011 Stock Incentive Plan (the “2011 Plan”) and its 2016 Equity Incentive Plan (the “2016 Plan”). The estimated fair value of options granted is determined as of the date of grant using the Black-Scholes option pricing model. The resulting fair value is recognized ratably over the requisite service period, which is generally the vesting period of the awards.

Share-based compensation expense for options granted under the 2016 Plan is reflected in the consolidated statements of operations as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Research and development	$	292	$	386	$	794	$	1,190
General and administrative		385		521		1,119		1,383
Total	$	677	$	907	$	1,913	$	2,573

The following table summarizes the activity related to stock options granted under the 2011 Plan and the 2016 Plan during the nine months ended September 30, 2025:


				Weighted
	Number of			Average
	Shares			Exercise Price
Options outstanding at December 31, 2024		842,867		$	36.97
Granted		171,695			14.20
Forfeited		(45,830	)		19.16
Options outstanding at September 30, 2025		968,732			33.78

Options exercisable at December 31, 2024		509,428			47.90

Options exercisable at September 30, 2025		634,079			42.59

As of September 30, 2025, the Company had $3.4 million of unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted average period of 2.3 years.

The Company has granted restricted stock units (“RSUs”) to employees and consultants under the 2016 Plan. The shares underlying the RSU awards have vesting terms of four years from the date of grant subject to the recipient's continuous service and subject to accelerated vesting in specified circumstances. The fair value of the RSUs granted is measured based on the market value of

the Company’s common stock on the date of grant and is recognized ratably over the requisite service period, which is generally the vesting period of the awards.

The total share-based compensation expense related to RSUs is reflected in the consolidated statements of operations as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Research and development	$	34	$	118	$	117	$	355
General and administrative		35		137		126		410
Total	$	69	$	255	$	243	$	765

The following table summarizes the activity related to RSUs during the nine months ended September 30, 2025:


				Weighted Average
	Number of			Grant Date
	Shares			Fair Value
Non-vested RSUs outstanding at December 31, 2024		29,155		$	44.36
Vested		(20,721	)		49.04
Non-vested RSUs outstanding at September 30, 2025		8,434			32.85

As of September 30, 2025, the Company had $0.1 million of unrecognized compensation expense related to the RSUs which is expected to be recognized over a weighted average period of 0.3 years.