Stock-based Compensation

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

10. Stock-based Compensation

Pursuant to the terms of the Company’s 2014 Equity Incentive Plan (“2014 Plan”), on January 1, 2023 and 2022, the Company automatically added 1,901,960 and 1,148,213 shares to the total number shares of common stock available for future issuance under the 2014 Plan, respectively. As of June 30, 2023, there were 504,074 shares of common stock available for future issuance under the 2014 Plan.

In July 2023, the Company’s board of directors amended the 2014 Employee Stock Purchase Plan (“ESPP Plan”), which was subsequently ratified by the Company’s stockholders and became effective on June 14, 2023. Common stock that may be issued under the ESPP Plan will not exceed 1,531,248 shares of common stock, which is the sum of: (i) the 4,779 shares of common stock originally approved; (ii) 26,469 shares of common stock that were added pursuant to the annual increase provision of the ESPP Plan between 2015 and 2023; and (iii) an additional 1,500,000 shares of common stock that were approved by our stockholders at the 2023 annual meeting of stockholders.

2015 Inducement Award Plan

As of June 30, 2023, there were 572,975 shares of common stock available for future issuance under the Company’s 2015 Inducement Award Plan (“2015 Plan”). During the six months ended June 30, 2023 and 2022, there were options to purchase zero and 92,000 shares of the Company’s common stock granted under the 2015 Plan, respectively.

The activity for the Company’s 2014 Plan and 2015 Plan, for the six months ended June 30, 2023, 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, 2022		1,740,308		$	12.21		6.16	$	—
Granted		303,000		$	1.87
Forfeited/Cancelled		(72,772	)	$	14.59
Outstanding — June 30, 2023		1,970,536		$	10.53		6.42	$	533
Exercisable — June 30, 2023		1,274,086		$	14.48		4.99	$	94
Vested or expected to vest — June 30, 2023		1,970,536		$	10.53		6.42	$	533

Restricted stock unit (“RSU”) activity under the 2014 Plan and 2015 Plan for the six months ended June 30, 2023, is summarized as follows:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Non-vested at December 31, 2022		633,270		$	5.29
Granted		1,929,575		$	1.79
Vested		(296,686	)	$	5.06
Forfeited		(71,908	)	$	2.92
Non-vested at June 30, 2023		2,194,251		$	2.32

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 25% annually over a four-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 and $1.1 million for the three months ended June 30, 2023 and 2022, respectively, and was $1.4 million and $2.0 million for the six months ended June 30, 2023, and 2022, respectively. The total income tax benefit recognized in the statements of operations for share-based compensation arrangements was zero for each of the three and six months ended June 30, 2023 and 2022.

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 June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	301	$	343	$	675	$	628
Selling, general and administrative		427		757		760		1,394
Total	$	728	$	1,100	$	1,435	$	2,022