DERIVATIVE INSTRUMENTS (Tables)

6 Months Ended

Jun. 30, 2017

DERIVATIVE INSTRUMENTS

Assumptions used in determining fair value of warrants

	June 30,		December 31,
	2017		2016
Risk free interest rate	1.4	%	1.2	%
Expected dividend yield	—	%	—	%
Contractual term (in years)	1.9		2.4
Expected volatility	82	%	89	%

Changes in derivative warrant liability

	Three Months Ended June 30,
	2017		2016
Balance at March 31,	$	1,073	$	2,954
Fair value of warrants issued		—		—
Reduction in derivative liability due to exercise and modification of warrants		—		—
Increase (decrease) in the fair value of warrants		(554)		(595)
Balance at June 30,	$	519	$	2,359

	Six Months Ended June 30,
	2017		2016
Balance at December 31,	$	1,314	$	1,907
Fair value of warrants issued		—		—
Reduction in derivative liability due to exercise and modification of warrants		—		—
Increase in the fair value of warrants		(795)		452
Balance at June 30,	$	519	$	2,359