Stock-Based Compensation

The 2012 Stock Incentive Plan

The 2012 Stock Incentive Plan ("2012 Plan") provided for the granting of stock options and restricted stock awards to employees, directors and consultants of the Company. Options granted under the 2012 Plan were either incentive stock options or nonqualified stock options. Incentive stock options were granted only to Company employees. Nonqualified stock options were granted to Company employees, outside directors and consultants. Options and awards under the 2012 Plan were granted for periods of up to ten years. Employee options granted by the Company generally vested over four years. In connection with the Company’s initial public offering of its common stock, the Company’s board of directors terminated the 2012 Plan effective as of January 27, 2015 and no further awards were issued under the 2012 Plan. However, any awards outstanding under the 2012 Plan at January 27, 2015 continue to be governed by the terms of the 2012 Plan.

The Amended and Restated 2014 Equity and Incentive Plan

The Amended and Restated 2014 Equity and Incentive Plan ("2014 Plan") provides for the issuance of (i) cash awards and (ii) equity-based awards, denominated in shares of the Company’s common stock, including incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock units, unrestricted stock awards, performance share awards and dividend equivalent rights. Incentive stock options may be granted only to Company employees. Nonqualified stock options may be granted to Company employees, outside directors and consultants. Options and awards under the 2014 Plan may be granted for periods of up to ten years. Employee options granted by the Company generally vest over four years. Restricted stock awards granted to employees, directors and consultants can be subject to the same vesting conditions and the right of repurchase by the Company of unvested shares as determined by its board of directors.

The following table summarizes option and award activity under the 2012 Plan and the 2014 Plan for the fiscal years ended December 31, 2018 and 2019:



	Shares Available for Grant		Outstanding Number of Shares		Weighted- Average Exercise Price per Share		Weighted- Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
Balance at January 1, 2018	29,571		99,029		$	25.33	8.46
Additional shares reserved	1,225,223		—		$	—
Options granted	(1,212,200	)	1,212,200		$	4.24
Options canceled/forfeited	15,072		(15,072	)	$	12.38
Shares expired under 2012 Plan	(1,867	)	—		$	—
Balance at December 31, 2018	55,799		1,296,157		$	5.75	9.23	$	—
Additional shares reserved	419,056		—		$	—
Options granted	(503,950	)	503,950		$	3.27
Options canceled/forfeited/expired	93,914		(93,914	)	$	6.03
Shares expired under 2012 Plan	(1,415	)	—		$	—
Balance at December 31, 2019	63,404		1,706,193		$	5.00	7.59	$	—
Exercisable at December 31, 2019			571,852		$	6.86	7.41	$	—

The aggregate intrinsic value is calculated as the difference between the exercise price of the option and the estimated fair value of the Company’s common stock for in-the-money options at December 31, 2019.

During the year ended December 31, 2019, the Company granted stock options to purchase 32,500 shares of common stock to non-employee directors.

Inducement Grants

The Company has also awarded inducement grants to purchase common stock to new employees outside the existing equity compensation plans in accordance with Nasdaq listing rule 5635(c)(4). Such options vest at a rate of 25% of the shares on the first anniversary of the commencement of such employee’s employment with the Company, and then one forty-eighth (1/48) of the shares monthly thereafter subject to such employee’s continued service. The following table summarizes the Company’s inducement grant stock option activities:



	Outstanding Number of Shares		Weighted- Average Exercise Price per Share		Weighted-Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
Balance at January 1, 2018	19,350		$	19.12	8.91	$	—
Options granted	—		$	—
Options canceled/forfeited	(5,513	)	$	15.40
Balance at December 31, 2018	13,837		$	20.60	4.52	$	—
Options granted	550,000		$	1.89
Options canceled/forfeited/expired	(9,723	)	$	17.81
Balance at December 31, 2019	554,114		$	2.08	9.76	$	—
Exercisable at December 31, 2019	3,228		$	27.20	3.77	$	—

The weighted-average grant-date fair value of options and awards granted during the years ended December 31, 2019 and 2018 was $2.55 and $4.24, respectively. The total fair value of options and awards that vested during the years ended December 31, 2019 and 2018 was $1.3 million and $1.0 million, respectively.

Stock-Based Compensation Expense

Total stock-based compensation expense recognized was as follows:



	Year Ended December 31, 2019		Year Ended December 31, 2018
	(in thousands)
Research and development	$	742	$	529
General and administrative	870		649
Total	$	1,612	$	1,178

At December 31, 2019, the Company had $4.2 million of total unrecognized stock-based compensation related to outstanding stock options that will be recognized over a weighted-average period of 3.00 years.

The following table presents the weighted-average assumptions for the Black-Scholes option-pricing model used in determining the fair value of options granted to employees:



	Year Ended December 31, 2019	Year Ended December 31, 2018
Dividend yield	—%	—%
Risk-free interest rate	1.60% - 2.66%	2.46% - 3.11%
Expected volatility	106.33%-107.76%	89%
Expected term (years)	5.96 - 6.08	6.08