Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of fair value of options granted

The weighted-average assumptions used in the Black-Scholes option-pricing model used to calculate the fair value of options granted during the nine months ended September 30, 2018, were as follows:

	Employee			Non-Employee
Expected volatility		71.0% -79.8	2%		N/A
Expected dividend yield		—			N/A
Expected term (in years)		3.0-3.5			N/A
Risk-free interest rate		1.58%-2.89	%		N/A

Schedule of stock option activity

The table summarizes the stock option activity, for both the 2018 and the 2015 plans, for the periods indicated as follows:

	Number of Options			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (1)
Outstanding at December 31, 2017		1,651,800		$	1.67		3.7	$	—
Granted		173,471		$	1.56		4.9	$	—
Exercised		(49,000	)	$	0.50		—	$	—
Forfeited		(50,500	)	$	—		—	$	—
Expired		—		$	—		—	$	—
Outstanding at September 30, 2018		1,725,771		$	1.57		4.4	$	—
Exercisable at September 30, 2018		1,436,050		$	1.57		3.9	$	—

(1) The aggregate intrinsic value on the table was calculated based on the difference between the estimated fair value of the Company’s stock and the exercise price of the underlying option. The estimated stock values used in the calculation was $0.69 and $0.72 per share for the nine months ended September 30, 2018 and the year ended December 31, 2017, respectively.

Schedule of stock-based compensation expense

The stock-based compensation expense was recorded as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Research and development	$	29	$	85	$	87	$	269
Selling, general and administrative		326		861		3,003		2,549
Total stock-based compensation expense	$	355	$	946	$	3,090	$	2,818

Schedule of summarizes restricted stock unit activity [Table Text Block]

The following table summarizes restricted stock unit activity for the nine months ended September 30, 2018:

	Number of  Units			Weighted Average Grant-Date Fair Value Per Units
Outstanding as of December 31, 2017		287,885		$	1.86
Granted		75,732		$	1.62
Vested		(187,128	)(1)	$	2.56
Forfeited		(3,577	)	$	6.99
Outstanding as of September 30, 2018		172,912		$	0.98

(1) In February 2018, the Company net issued 32,625 shares of common stock to a former employee of the Company under the employee’s separation agreement, which accelerated the vesting of certain restricted stock units.