Stock-based Compensation

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

9. Stock-based Compensation

Pursuant to the terms of the Company’s 2014 Equity Incentive Plan (“2014 Plan”), on January 1, 2024 and 2023, the Company automatically added 1,916,962 and 1,901,960 shares to the total number shares of common stock available for future issuance under the 2014 Plan, respectively. As of March 31, 2024, there were zero shares of common stock available for future issuance under the 2014 Plan.

2015 Inducement Award Plan

As of March 31, 2024, there were 637,050 shares of common stock available for future issuance under the Company’s 2015 Inducement Award Plan (“2015 Plan”). During both the three months ended March 31, 2024 and 2023, there were options to purchase zero shares of the Company’s common stock granted under the 2015 Plan.

The activity for the Company’s 2014 Plan and 2015 Plan, for the three months ended March 31, 2024, is summarized as follows:


	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value ($000)
Outstanding — December 31, 2023		1,867,795		$	10.72		6.10	$	184
Granted		862,060		$	1.86
Forfeited/Cancelled		(13,253	)	$	7.84
Outstanding — March 31, 2024		2,716,602		$	7.92		7.11	$	—
Exercisable — March 31, 2024		1,389,304		$	13.35		4.99	$	—
Vested or expected to vest — March 31, 2024		2,716,602		$	7.92		7.11	$	—

Restricted stock unit (“RSU”) activity under the 2014 Plan and 2015 Plan for the three months ended March 31, 2024, is summarized as follows:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Non-vested at December 31, 2023		1,886,374		$	2.28
Granted		1,877,940		$	1.88
Vested		(553,182	)	$	3.03
Forfeited		(9,120	)	$	2.15
Non-vested at March 31, 2024		3,202,012		$	1.91

The fair value of RSUs is based on the market price of the Company’s common stock on the date of grant. RSUs generally vest 33% annually over a three-year period from the date of grant. Upon vesting, the RSUs generally are net share settled to cover the required withholding tax with the remaining shares issued to the holder. The Company recognizes compensation expense for such awards ratably over the corresponding vesting period.

Compensation Cost

The compensation cost that has been charged against income for stock awards under the 2014 Plan and the 2015 Plan was $0.7 million for each of the three months ended March 31, 2024 and 2023. The total income tax benefit recognized in the statements of operations for share-based compensation arrangements was zero for each of the three months ended March 31, 2024 and 2023.

Stock-based compensation expense related to stock options is included in the following line items in the accompanying unaudited condensed consolidated statements of operations (in thousands):


	Three Months Ended March 31,
	2024		2023
Research and development	$	195	$	374
Selling, general and administrative		510		333
Total	$	705	$	707