Stock-Based Compensation

9 Months Ended

Sep. 30, 2019

11. Stock-Based Compensation

The Company recognized stock-based compensation expense on all employee and

non-employee

awards as follows:


	For the three months ended September 30,				For the nine months ended September 30,
(in thousands)	2019		2018		2019		2018
Research and development	$	339	$	552	$	1,068	$	1,765
General and administrative		1,147		928		3,673		5,085
Stock-based compensation expense	$	1,486	$	1,480	$	4,741	$	6,850

The Company granted an aggregate of 140,000 and 1,835,755 stock options during the three and nine months ended September 30, 2019 with a weighted-average grant date fair value of $3.05 and $1.90 per share, respectively. The Company granted an aggregate of 300,500 and 506,000 stock options during the three and nine months ended September 30, 2018 with a weighted average grant date fair value of $2.11 and $2.49 per share, respectively.

On January 6, 2019, the Company paid an accrued annual performance bonus by issuing 446,428 shares of common stock.

On June 13, 2019 the Company extended the contractual life of 52,500 fully vested stock options held by a director of the Company. Additionally, on June 13, 2019, the Company accelerated the vesting and extended the contractual life of 126,700 stock options held by a director. These extensions and acceleration of vesting resulted in additional stock compensation expense of $0 and $0.4 million in the three and nine months ended September 30, 2019.

On February 15, 2018, the Company extended the contractual life of 751,667 fully vested stock options held by an officer of the Company by an additional nine months. Additionally, on March 12, 2018, the Company extended the contractual life of 117,500 fully vested stock options held by a director. These extensions did not result in additional stock compensation expense for the three months ended September 30, 2018. Additional stock compensation expense of $0.5 million was recorded for the nine months ended September 30, 2018.

For the three months ended September 30, 2019 and 2018, the fair value of stock options was estimated on the date of grant using a Black-Scholes option valuation model with the following assumptions:


	For the three months ended September 30,
	2019	2018
Risk-free interest rate	1.39 - 1.92%	2.82 - 2.98%
Expected life in years	6.25	6
Expected volatility	72.87 - 78.34%	82.27 - 83.08%
Expected dividend yield	0	0

Stock option activity under the Company’s stock option plan for the nine months ended September 30, 2019 is as follows:


(in thousands, except share and per share data)	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding, December 31, 2018		5,277,085		$	4.24
Granted		1,835,755			2.69
Exercised		(482,500	)		3.48
Cancelled		(1,634,791	)		4.11

Outstanding, September 30, 2019		4,995,549		$	3.78		7.84	$	6,025

Options exercisable, September 30, 2019		2,581,327		$	4.59		6.60	$	2,425

Options exercisable, December 31, 2018		3,099,935		$	5.15		4.93	$	88

Options available for future grant		3,971,940

At September 30, 2019, total unrecognized compensation costs related to unvested stock options outstanding amounted to $6.7 million. The cost is expected to be recognized over a weighted-average period of 1.78 years.

A summary of the status of unvested restricted stock for the nine months ended September 30, 2019 is as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value
Non-vested, December 31, 2018		682,070		$	3.47
Granted		1,408,536			2.26
Vested		(446,428	)		2.24
Cancelled		(74,599	)		3.41

Non-vested, Se ptember 30, 2019		1,569,579		$	2.91

At September 30, 2019, total unrecognized compensation costs related to unvested restricted stock outstanding amounted to $2.8 million. The cost is expected to be recognized over a weighted-average period of 1.48 years.