Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Stock-Based Compensation

Schedule of stock option activity under the Company's Equity Incentive Plans

		Weighted
		Average		Weighted	Aggregate
		Exercise Price		Average Remaining	Intrinsic
	Options	Per Share		Life in Years	Value
Outstanding at December 31, 2017	2,257,621	$	12.38	8.66	$	68
Granted	599,050	$	6.68
Exercised	(2,478)	$	5.56
Forfeited	(92,281)	$	7.89
Outstanding at December 31, 2018	2,761,912	$	11.30	8.01	$	—
Granted	1,481,975	$	1.48
Forfeited	(219,321)	$	15.14
Outstanding at December 31, 2019	4,024,566	$	7.48	7.98	$	2
Options exercisable at December 31, 2019	2,398,685	$	10.48	7.25	$	—
Options vested and expected to vest at December 31, 2019	4,024,566	$	7.48	7.98	$	2

Schedule of assumptions used to determine grant-date fair value of stock options

	Year Ended		Year Ended
	December 31,		December 31,
	2019		2018
Expected volatility	66.94	%	66.94	%
Weighted average risk-free interest rate	2.07	%	2.80	%
Expected dividend yield	0.00	%	0.00	%
Expected term (in years)	6.77		6.95

Schedule of stock-based compensation expense classified in the consolidated statements of operations and comprehensive loss

	Year Ended
	December 31,
	2019		2018
Research and development	$	714	$	625
General and administrative		3,018		2,844
Total	$	3,732	$	3,469

Summary of outstanding RSU's under the 2016 Plan

		Weighted
	Number of	Average
	Shares	Fair Value
Outstanding at December 31, 2018	—	$	—
Awarded	181,000	$	1.74
Settled in cash	(90,500)	$	1.17
Outstanding at December 31, 2019	90,500	$	1.76