Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value of Assets and Liabilities Measured on Recurring Basis

The following tables present the assets and liabilities the Company has measured at fair value on a recurring basis (in thousands):

			Fair Value Measurements at
			Reporting Date Using
			Quoted Prices in		Significant Other		Significant
			Active Markets for		Observable		Unobservable
			Identical Assets		Inputs		Inputs
Description	September 30, 2018		(Level 1)		(Level 2)		(Level 3)
Assets
Money market funds (included in cash and cash equivalents)	$	1,091	$	1,091	$	—	$	—
Total assets	$	1,091	$	1,091	$	—	$	—
Liabilities
Warrant liability	$	16	$	—	$	—	$	16
Total liabilities	$	16	$	—	$	—	$	16

			Fair Value Measurements at
			Reporting Date Using
			Quoted Prices in		Significant Other		Significant
			Active Markets for		Observable		Unobservable
			Identical Assets		Inputs		Inputs
Description	December 31, 2017		(Level 1)		(Level 2)		(Level 3)
Assets
Money market funds (included in cash and cash equivalents)	$	2,584	$	2,584	$	—	$	—
Total assets	$	2,584	$	2,584	$	—	$	—
Liabilities
Warrant liability	$	29	$	—	$	—	$	29
Total liabilities	$	29	$	—	$	—	$	29

Assumptions Used in the Black-Scholes Option Pricing Model to Determine the Fair Value of the Common Stock Warrants

The assumptions used in the Black-Scholes option pricing model to determine the fair value of the Consultant Warrant as of September 30, 2018, and December 31, 2017 were as follows:

	September 30,			December 31,
	2018			2017
Exercise price (A$55.00 at the then current exchange rate)	$	0.64		$	0.64
Fair value of common stock	$	0.72		$	0.60
Expected volatility		135.0	%		142.6	%
Expected term (in years)	2.61			3.34
Risk-free interest rate		2.9	%		2.0	%
Expected dividend yield		—	%		—	%

Rollforward of Fair Value of Warrants

The following table rolls forward the fair value of the Warrants, where fair value is determined by Level 3 inputs (in thousands):

Balance at December 31, 2017

Decrease in fair value of warrants upon re-measurement included in

other income (expense), net

(13

)

Balance at September 30, 2018