INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2015

INCOME TAXES

Schedule of significant components of net deferred tax asset

	December 31,
	2015			2014
Net operating loss carryforward	$	30,014		$	22,490
Research and development credit carryforward		942			801
Stock-based compensation		3,307			2,265
Depreciation and amortization		(48	)		(124	)
Accrued expenses		186			226
Charitable contributions		96			112
Subtotal		34,497			25,770
Valuation allowance		(34,497	)		(25,770	)
Net deferred taxes	$	—		$	—

Schedule of income tax benefits computed using the federal statutory income tax rate differs from effective tax rate

	December 31,
	2015			2014			2013
Statutory rate		(34.0	)%		(34.0	)%		(34.0	)%
State taxes, net of benefit		(3.5	)%		(4.8	)%		(2.6	)%
Permanent differences:
Derivative losses		11.0	%		0.7	%		17.1	%
Other		0.3	%		2.6	%		0.0	%
R&D tax credit		(0.4	)%		(1.0	)%		(0.4	)%
Other		0.4	%		2.2	%		0.0	%
Increase in valuation reserve		26.2	%		34.3	%		19.9	%
Effective tax rate		0.0	%		0.0	%		0.0	%