Fair Value of Financial Assets and Liabilities - Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2015

Derivatives And Fair Value [Line Items]

Financial Liabilities Measured at Fair Value

The following fair value hierarchy table presents information about each major category of the Company's financial liabilities measured at fair value on a recurring basis:

	Quoted Prices in
	Active Markets		Significant Other		Significant
	for Identical		Observable Inputs		Unobservable
	Items (Level 1)		(Level 2)		Inputs (Level 3)		Total
December 31, 2015
Liabilities
Series B redeemable convertible preferred stock	$	-	$	-	$	1,493,000	$	1,493,000
Warrant liability		-		-		6,000		6,000
Total liabilities	$	-	$	-	$	1,499,000	$	1,499,000
December 31, 2014
Liabilities
Series B redeemable convertible preferred stock	$	-	$	-	$	12,320,000	$	12,320,000
Warrant liability		-		-		5,826,000		5,826,000
Total liabilities	$	-	$	-	$	18,146,000	$	18,146,000

Changes in Fair Value of Derivative and Warrant Liability

The following table sets forth a summary of changes in the fair value of the Company's Series B redeemable convertible preferred stock derivative and warrant liabilities, which represents a recurring measurement that is classified within Level 3 of the fair value hierarchy, wherein fair value is estimated using significant unobservable inputs:

			Series B
	Warrant		Redeemable
	Liability		Preferred Stock
Balance, December 31, 2014	$	5,826,000	$	12,320,000
Issuances		4,210,000		-
Exercises		(677,000)		-
Conversions to common stock		-		(1,497,000)
Warrants reclassified from liabilities to equity due to amendment of warrants		(5,462,000)		-
Warrants reclassified from liabilities to equity due to increase in authorized shares		(3,281,000)		-
Changes in estimated fair value		(610,000)		(9,330,000)
Balance as of December 31, 2015	$	6,000	$	1,493,000

Series B redeemable convertible preferred stock [Member]

Derivatives And Fair Value [Line Items]

Valuation Assumptions Used

The following assumptions were used at December 31, 2015 and December 31, 2014:

	December 31, 2015			December 31, 2014
Volatility		108 to 117	%		91	%
Expected term (years), weighted average		0.50 to 2.50			1.25
Risk-free interest rate		0.49 to 1.19	%		0.36	%
Dividend yield		0.00	%		0.00	%
Exercise price	$	7.00		$	7.00
Common stock closing price	$	3.98		$	10.50

Warrant [Member]

Derivatives And Fair Value [Line Items]

Valuation Assumptions Used

The following assumptions were used at December 31, 2015 and December 31, 2014:

	December 31, 2015			December 31, 2014
	Series (1)			Series (1)
							June			July			December
	2011			2011			2013			2013			2013
Volatility		112	%		155	%		155	%		155	%		151	%
Expected term (years)		0.98			1.98			3.49			3.54			3.98
Risk-free interest rate		0.64	%		0.67	%		1.23	%		1.25	%		1.37	%
Dividend yield		0.00	%		0.00	%		0.00	%		0.00	%		0.00	%
Exercise price	$	23.00		$	23.00		$	7.00		$	7.00		$	12.50
Common stock closing price	$	3.98		$	10.50		$	10.50		$	10.50		$	10.50

(1) See Note 11 – Warrants below for further description of the respective series of warrants.