Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Measurements

Schedule of financial assets and liabilities at fair value by respective level of the fair value hierarchy

	Level 1		Level 2		Level 3		Total
	(in thousands)
At March 31, 2015
Assets:
Cash and cash equivalents	$	6,052	$	—	$	—	$	6,052
Short-term investments	119		—		—		119
Trade accounts receivable	92		—		—		92
	$	6,263	$	—	$	—	$	6,263
Liabilities:
KELTIP liability	$	71	$	—	$	—	$	71
Warrant liability	—		—		904		904
	$	71	$	—	$	904	$	975
At December 31, 2014
Assets:
Cash and cash equivalents	$	8,579	$	—	$	—	$	8,579
Trade accounts receivable	—		—		—		—
	$	8,579	$	—	$	—	$	8,579
Liabilities:
KELTIP liability	$	93	$	—	$	—	$	93
Warrant liability	—		—		1,554		1,554
	$	93	$	—	$	1,554	$	1,647

Schedule of significant inputs to the valuation model

	March 31,			December 31,
	2015			2014
Company’s ending stock price	$	0.41		$	0.54
Company’s stock volatility	85		%	90		%
Applicable risk free interest rate	1.3		%	1.6		%

Summary of change in fair value of the warrant liability

	Fair Value Measurements
	Using Significant Unobservable
	Inputs (level 3)
	Warrant Liabilities
	(in thousands)
Beginning balance at January 1, 2015	$	1,554
Change in estimated fair value	(650		)
Ending balance at March 31, 2015	$	904